EcoEngineering

Pass The Sirop de Poteau

2012-01-06T12:01:00.000-05:00

Being born and raised in Quebec meant always having an abundant supply of top grade maple syrup on the table. I never even tried imitation "sirop de poteau" (syrup from telephone polls) , as it's called in Quebec until I was a young adult traveling abroad.

It was always taken for granted, yet if we continue warming the planet at the same rate, most sugar maples will be gone by 2100.

In fact, Martha Carlson of Range Veiw Farms breaks down the way sweetness in maple sap has already begun to decline (along with a 2.8-degree-F rise in temperature since 1970); today's maple sap has gone from 3.5 percent sugar to just 2 percent sugar in the last 40 years.

Alternative Deicer from Organic Waste Streams

2010-05-18T18:53:00.019-04:00

This report describes a comprehensive laboratory and field evaluation intended to determine the performance of CDS (Condensed Distillers Soluble) in particular and with chloride salt co-products in ice control operations. The study shows when mixed with co-products, CDS is effective for ice control operations, able to melt ice faster and at lower temperatures than traditional ice control agents, with little or no adverse effects on infrastructure or the environment.
The following three basic objectives for the evaluation of CDS and co-products have been established:

To characterize the physio-chemical properties.
To determine performance in melting ice and resolve operational issues.
To determine effects on the environment.

Significant research has been carried out recently on the development of deicers from agricultural by-products including corn, wheat, and rice. These developed materials are all proprietary products and little information is available in the technical literature, however, information about similar products is found in the patent literature. Table 1 in Appendix A lists the existing deicing agents from agricultural products reviewed in this study. Of these, Ice-B-Gone and IceBan are found to have particular qualities suitable for comparisons to CDS in the absence of test data.

PHYSIO-CHEMICAL PROPERTIES
CDS is the concentrated liquid residue from the processing of distillers grains having an involved chemical composition consisting primarily of complex soluble carbohydrates and proteins. CDS can be used alone or mixed with co-product as stockpile treatment pre-wetting agent and in anti-icing or deicing liquid programs.

CDS typically 40% solids (w/w), can be purchased off-the-shelf, processed to the desired solids content, and mixed with additives or co-products. DDGS (Dried Distillers Grain with Solubles) specimens were available; therefore, liquid residues were extracted by steeping DDGS in hot tap water to achieve 10 - 20 percent solids w/w solution (Figure 1) subsequently evaporated until the appearance of a tactile solution formed between the fingers. The solution is similar to molasses in color, has a pleasant odour comparable to that of cooked corn, but is less viscous, and appears to have non-newtonian properties beneficial as a melting agent. The solution dissolves readily in water and dries to a dark brown cake.

Although beyond the scope of this project, a thorough chemical composition of CDS from dry-grind by-products was conducted by the Laboratory of Renewable Resources Engineering [d1] and serves as a suitable comparison. Table 1 below is a summary of major CDS components from a typical brewery process.

Similarly, the physio-chemical properties of chlorinated salt co-products are well known and documented in other literature. Figure 1 in Appendix A shows the most common co-products used along with useful operating parameters. A brief summary of co-product controlling factors as they relate to CDS performance are outlined below.

CO-PRODUCTS
Standard co-product solutions were prepared by dissolving appropriate amounts of reagent grade salts at room temperature, cooled down to 3±2ºC for 24 hours, and supernatant collected to produce a solutions at working temperature. Three additional test solutions of 1:1 (by volume) with CDS were prepared for each co-product. Raw data and calculations for the make-up of each solution are included in Appendix A, Figure 2.

Table 2 below shows various combinations of CDS and co-product selected for study. In order to facilitate end users, CDS can be prepared at concentrations specific to the mix ratios for a particular process. CDS N50 for example, would designate a required mix ratio of 50:50 with sodium chloride, C20 would designate a 20:80 mix with calcium chloride, M30 for 30:70 with magnesium chloride and so on, however, only the concentration below were tested.

Table 2 - Test Solution combinations
I.D.	Combination
A	50% CDS
B	23% NaCl
C	22% MgCl₂
D	30% CaCl₂
E	50% A + 50% B
F	50% A + 50% C
G	50% A + 50% D
H	BlueFuzion^TM

In solid form, salts are unable to melt ice or snow until a brine is formed, which lowers the freezing point of the water until the solution becomes so diluted that its freezing point approaches the ground temperature. It is further hypothesized that when mixed with CDS, the larger particle size contributes to lowering dilution rates and increased sorption sites for the co-product in solutions, thereby providing greater retention and residual effects on applied surfaces.

In addition to having lower eutectic points and working temperatures, the hygroscopic nature of calcium and magnesium chlorides allow them to begin working immediately upon contact with ice or snow. Moreover, calcium and magnesium chlorides produce exothermic reactions, releasing heat as they dissolve into a brine solution. One kilogram of calcium chloride releases 640 British Thermal Units (Btu) as it dissolves, raising the temperature of the water. Magnesium chloride has less heat-release capability, about 57 Btu per kilogram, because it is a hexahydrate salt (about 47% MgCl2/ 53% H2O). The remaining deicers such as sodium chloride, potassium chloride and urea produce endothermic reactions (1 kg NaCl = 86 Btu, Urea = 234 Btu, KCl = 375 Btu), lowering the temperature of the water as they form a brine.

Magnesium and calcium chlorides also have higher theoretical melting capacities per unit weight at temperatures much lower than sodium chloride. For reasons mentioned above, the chloride salts of magnesium and calcium exhibit eutectic compositions and freezing point depressions substantially lower than predicted via the freezing point depression constant for water (KF = 1.86).

HYDROGEN ION CONCENTRATION (pH)
Initially, pH values of straight solutions were erratic and gave somewhat unexpected results. For example, a 1:1 mix of A & D was expected to have pH somewhere between 3.5 and 10, however, initial readings of 2.5 were measured. To remedy the situation, samples were diluted 1:4 with water to prevent the conductivity from the relatively high chloride content from overwhelming the pH test probe. Raw data are included in Appendix A, Figure 3 and summarized below.

Table 3 – Solution pH
I.D.	Description	pH
A	50% CDS	3.7
B	23% NaCl	7.0
C	22% MgCl₂	6.0
D	30% CaCl₂	9.3
E	50% A + 50% B	3.8
F	50% A + 50% C	3.5
G	50% A + 50% D	3.8
H	BlueFuzion^TM	6.3

As shown in Table 3 above, traditional deicers (B,C,D) are either neutral or alkaline, whereas A and blends with co-products (E,F,G) are acidic. Lower pH is generally associated with greater corrosion of metals, however, it should be noted that CDS was found to be less corrosive than pH neutral, pure water. [ASCE 13] It is hypothesized that in the presence of minute electrical currents that cause corrosion, the hydrocarbon and protein combination reportedly “forms a gel or film which acts as a cathodic protection agent against corrosion.” Therefore, factors associated with pH may be different than expected and the rational for restricting acidity/alkalinity on corrosion effects are no longer controlling.

SOLIDS & INSOLUBLES CONTENT
The total solids content and the amount of insoluble material can affect the performance and handling characteristics of the product. A high insoluble content may lead to settling out during transport and storage, plug nozzles, or cause other operational problems. The total solids content is directly proportional to the amount of solute and is indicative of the freezing point depressions associated with eutectic points.

A straightforward approach was used to measure the total solids in CDS specimens: A volume of solution was weighed and dried to determine % solids. Any attempts to determine insoluble content of CDS was met with great difficulty despite different methods (gravity filtering, vacuum methods). Due to the high viscosity, the 2.5 micron filter became immediately clogged. Nonetheless, after appropriate dilution and vacuum filtering, a sufficient specimen was collected to measure total insolubles content. Raw data and calculations for solids and insolubles are included in Appendix A, Figure 4.

Straight CDS (A) was determined to have a measure solids content of 49 percent of which almost all is soluble and insolubles content of 4 percent. When mixed 1:1 with 30 percent magnesium chloride solution for example, the resulting solution has a solids content of about 40 percent.

VISCOSITY
CDS is significantly less viscous than oil at lower temperatures. The fact that CDS is relatively viscous to water will have both positive and negative effects. End users may need to adjust their equipment to ensure that the product is applied correctly. On the other hand, a highly viscous liquid tends to resist flow and forms a more tenacious bond to the various surfaces to which it is applied (salt, abrasives, or ice/pavement), thereby providing better ice melting performance.

The absence of a viscometer precluded measurement of the effects of CDS specimens mixed with co-products. However, a literature review did provide estimates of viscosity for various solutions at working temperature and are listed in Table 4 below.

Table 4 - Viscosity of Solutions [d3]
I.D.	Description	Viscosity cps @ 0ºC
A	50% CDS	100 to 140^[d3]
B	23% NaCl	9
C	22% MgCl₂	-
D	30% CaCl₂	10
E	50% A + 50% B	-
F	50% A + 50% C	-
G	50% A + 50% D	-

CDS has high solids content composed of complex hydrocarbon and protein chains that are likely to impart non-newtonian properties to the liquid. It was observed that the viscosity of the syrup mixture increases as the moisture level of the mixture decreases and the lower moisture specimens have properties consistent with that of pressure sensitive adhesives.

If so, the dilatant nature of CDS equates to greater splash resistance and adhesion by increasing the liquid viscosity as shear forces increase. Moreover, higher viscosity means more resistance to cool currents of air. CDS is readily soluble in water and therefore, viscosity is easily controlled by dilution. Moreover, patent holders claim the pH of CDS may also be adjusted to reduce the viscosity of the syrup mixture to a desired level.

DENSITY
The density of any engineered product is an important consideration for transport or when sizing holding tanks and application equipment. Additionally, converting brine volume to weight of ice melted requires a determination of the specific volume of the deicer (the reciprocal of its density). The density of chilled CDS and co-products were measured in a straightforward fashion using 10ml volumetric pipettes and an analytical balance. Raw data and calculations for the density tests performed on CDS and co-products are included in Appendix A, Figure 5 and summarized in Table 5 below.

Table 5 - Density of Solutions
I.D.	Description	Density (g/cm³)
A	50% CDS	1.24
B	23% NaCl	1.22
C	22% MgCl₂	1.25
D	30% CaCl₂	1.29
E	50% A + 50% B	1.16
F	50% A + 50% C	1.17
G	50% A + 50% D	1.21
H	BlueFuzion^TM	1.29 ^[d7]

Despite the high solids content, CDS has a density slightly higher than sodium chloride, but less than magnesium and calcium chloride co-products.

PHASE DIAGRAM
While beyond the scope of this report, a literature review did provide an estimation for the freezing point depression of CDS in relation to various co-products. CDS from corn mixed with magnesium chloride (Ice Ban Magic) were reported by NASA testing [ASCE 45] to have a lower minimum freezing point than sodium and magnesium chloride, but higher than for calcium chloride. The results of NASA’s freezing point determination are shown in Figure 2 below. The eutectic concentration for a 40 percent solids solution is higher than that for the common chloride based deicers (23.3 percent for sodium, 21.6 percent for magnesium, and 29.8 percent for calcium chlorides).

ICE MELT TEST
To determine the effectiveness of CDS as an deicing agent in general and its performance compared to chloride salts in particular, a series of tests were conducted in harmony with the "Handbook of Test Methods for Evaluating Chemical Deicers", SHRP-H/WP-90, Strategic Highway Research Program, National Science Counsel, Washington, D.C., (1992)" protocols and guidelines. More specifically, H-205.2 ice melting test and H-205.4 ice penetration test were performed in addition to rudimentary field tests in order to make reasonable estimates on various parameters likely to affect or enhance performance of CDS and co-products as deicing agents.

The first series of tests provided a measure of two fundamental characteristics; the amount of ice melted by each of the products (g product/g ice melted) and the rate of melting (g/min.). Strictly speaking, the test calls for a special apparatus fabricated from Plexiglass and testing within a cold room enclosure over a range of temperatures. To make ends meet, disposable Petri dishes (Figure 3) where recycled into an apparatus and the tests were performed in a make-shift enclosure (Appendix A - Figure 6) set at 8ºF (-13.3 ºC).

Each test consisted of applying 5ml volume of deicer containing a small amount of dye (red=NaCl, green=MgCl2, blue=CaCl2) to an 8mm thick layer of ice (about 40ml water), then decanting and measuring the volume of brine generated at selected time intervals. Raw data accumulated in the ice melting test for liquids is included in Appendix A, Figure 7 to 8, and results are tabulated in Table 6 below.

Table 6 - Melt Test Results
Mix	Description	Brine Volume (ml/g)	Unit Quantity of Melt (g/g)
A	50% CDS	1.3	0.5
B	23% NaCl	1.3	0.5
C	22% MgCl₂	1.7	0.9
D	30% CaCl₂	1.8	1.1
E	50% A + 50% B	1.6	0.8
F	50% A + 50% C	2.0	1.2
G	50% A + 50% D	2.4	1.6

A two-step treatment of raw data obtained in the ice melting tests was conducted. The first step consists of conversion of brine volumes to volumes per unit weight of deicer as charged (ml brine/g deicer). The second step consists of calculating the quantity of ice melted, expressed as grams of ice melted per gram of deicer liquid. Figure 4 below charts the brine volumes generated and the rate of ice melting for combinations of CDS and co-products.

Initial melt rates (within the first ten minutes) remain relatively the same for each combination of CDS and co-product, however, it is evident that solutions containing CDS are “slower acting” than solutions without, shortly after application. In the case of NaCl, it is ineffective after 30 minutes, whereas CaCl2 and MgCl2 are about twice the capacity becoming ineffective only after 50 minutes when used alone. The addition of CDS however, not only increases the melt rate of the brine moving forward but continues to work long after conventional salt brines fail. Perhaps more interesting is the synergistic effects the CDS and co-products have on eachother. As shown in the chart at the top of Figure 4, CDS is as effective as NaCl brine alone, however, an apparent synergistic relationship exists between the two which allows the brine solution to work long after either would fail. The same is true for mixtures of magnesium or calcium chlorides and CDS.

Figure 5 below shows the unit quantity of ice melted per gram of deicer applied for combinations of CDS and co-products.

As shown in Figure 5, gram for gram, CaCl2 provides the best melt capacity of any other chloride salt alone, although the effects are greatly magnified in each case with the addition of CDS. Not only does the addition of CDS increase the amount of ice melted per gram of solution, it lowers the freezing point of the brine while potentially doubling the working time.

ICE PENETRATION TEST
The second series of tests measured the ability of the ice control agents to penetrate vertically through a given thickness of ice and the rate of penetration. This ability to cut through an ice layer to reach the pavement surface is an essential prerequisite for the deicer to perform successfully in weakening or destroying the bond at the ice/pavement interface. For liquids, this action is achieved once it pools on the surface, forming a cone as it descends, where it reaches the pavement and continues to spread.

Once again, recycled materials were utilized in an unorthodox fashion to accomplish test objectives. Each test consisted of placing a few drops (about 0.5ml) of solution containing dye on ice contained in a special test fixture as shown in Figure 6 and recording the depth of penetration at regular intervals of 10 minutes over a one-hour period. The deicers were placed on the ice in the test cell at preset temperatures of 8ºF (-13.3ºC).

When penetration occurred uniformly and evenly in the cavity, one depth was recorded. When penetration deviated and tendrils appeared, two depths were recorded. The first depth recorded was the uniform depth and the second the tendril depth. These two numbers were added together to obtain the effective penetration.
Raw data and calculations are included in Appendix A, Figure 9 to 10, and results are tabulated in Table 7 below.

Table 7 - Ice Penetration Results
Mix	Description	Ice Penetration (mm)
A	50% CDS	2.0
B	23% NaCl	0.5
C	22% MgCl₂	3.5
D	30% CaCl₂	4.5
E	50% A + 50% B	2.0
F	50% A + 50% C	4.0
G	50% A + 50% D	5.5

Figure 7 below shows the rate of ice penetration for combinations with CDS and co-products.

As shown in Figure 7, calcium chloride penetrates faster and farther than other chloride salts examined, although combinations of co-products with CDS consistently penetrated ice to a greater depth and at a faster rate than did the chloride salts alone. In the case of sodium chloride alone, there is negligible penetration within the first 10 minutes and it becomes ineffective after 30 minutes. Conversely, magnesium and calcium chlorides are seen to begin working immediately and remain effective almost twice as long as sodium chloride.

ECOTOXICOLOY
Behind all of the issues mentioned above, is the added concern that the compounds eventually wash off pavement onto the soil or into water treatment works. Materials that are toxic are therefore not acceptable deicing materials. The objective of this section is to determine if the proposed deicing product and co-products pose a significant risk to the environment and to provide a measure for determining whether those risks are sufficient to preclude use of the material or to prescribe limitations for its use.

The first series of tests involve the exposure of lettuce seed to co-products at specific concentrations under controlled conditions and measuring the mortality rates or evidence of chronic effects. Exposure levels range from those required to cause mortality to levels near estimated environmental concentrations. The second series of tests evaluates the effects of a stream containing CDS might have on bacteria such as that found in and an activated sludge process or specialized population of organisms. To this end, the Polytox™ test is used to measure respiration rates of standard aerobic bacterium in the presence of CDS solution and to evaluate the inhibition rates. Finally, a test was designed to characterise the effects on vermicompost biota and abiota and to describe effective mitigation measures towards improving system relationships and performance outputs.

SEED GERMINATION/ROOT ELONGATION
Lettuce seed was selected as a suitable indicator for addressing environmental impacts in accordance with the EPA’s 1996 Ecological Effects Test Guidelines. More specifically, the Seed Germination/ Root Elongation Toxicity Test [d4] was conducted on brines of sodium chloride and magnesium chloride. Brine specimens were prepared from materials obtained from the Ville-Marie stockpile although tests were not conducted on calcium chloride as it is not considered toxic to the environment [d5] in relative quantities expected for the design. By the same token, CDS is an agricultural product commonly sold as feed for livestock or fertilizer and has been shown to have benefits at the fruiting stage [d6], however, a separate series of tests was conducted with CDS on seed germination to observe effects.

Fresh lettuce seed were sourced from Johnny’s Selected Seeds (Appendix A, Figure 11). A control group was initially prepared on three types of substrates; sand, Whatman filter paper (Figure 8), and off the shelf paper towels. While tests performed in sand were successful, it was deemed unsuitable as a substrate due to additional preparation and handling requirements. The Whatman filter paper proved to be ineffective at retaining moisture and no better than 80% seed germination could be achieved. After the first 24 hours, water droplets were seen forming on the lid of Petri dishes containing filter paper with sections having lifted (bubbled) from the bottom surface and dried out. Consequently, some seeds were not in direct contact with water and could not germinate. Off-the-shelf paper towel, however, proved to be effective, and the remaining tests were conducted using the later substrate.

Fifteen seeds were placed on paper towel saturated with 6ml of bracketed concentrations of salt solutions, then incubated at 25 ± 1ºC in the dark for 120 hours (5 days). After 5 days, the number of seeds germinated was counted and the radical length was measured to the nearest mm as shown in Figure 9. Concentration response curves as well as LD50s for seed germination and root elongation are determined statistically and reported for each of the solutions tested.

Raw data and calculations are attached in Appendix A, Figures 12 to 13, and are tabulated in Table 8 below.

Concentration (mg/L)	B		H
Concentration (mg/L)	% Germinated	Mean Radicle Length (mm)	% Germinated	Mean Radicle Length (mm)
0	100	33	100	34
375	93	31	93	33
750	87	30	93	32
1500	87	28	87	27
3000	73	22	87	22
6000	73	18	80	20
9000	60	11	60	15
12000	47	7	53	10

Figure 10 below plots the percentage of seeds germinated for varying concentrations of sodium chloride and magnesium chloride. Additionally, best fit curves are plotted for each solution with corresponding equations and confidence. An exponential fit provided the best estimates and was selected after applying linear, log, and 2nd curve fits in Excel.

From the best fit curves it can be estimated that sodium chloride has an LD50 of approximately 11,000mg/L. By comparison, the LD50 for magnesium chloride is estimated to be around 15,000mg/L, demonstrating a 36% increase in tolerance over sodium chloride alone.

Figure 11 below is a plot of lettuce seed radical lengths at varying concentrations of sodium and magnesium brines. Again, it is seen that magnesium chloride produces longer average radical lengths than sodium chloride. In fact, it is observed that there is on the order of a 5-10% increase in radical length overall for magnesium salt in comparison to sodium chloride.

The results indicate that sodium chloride is toxic to lettuce seed at concentrations above 11,000 mg/L and there are adverse effects on radical length (i.e. 10% reduction) at concentrations as low as 1,500mg/L. By comparison, the addition of magnesium chloride increases tolerance of lettuce seed to concentrations over 15,000 mg/L, however, there is also a negative effect on radical length at concentrations similar to sodium chloride as observed by a higher incidence of tugor (dark discoloration of the radical) in seeds sown with magnesium chloride (Figure 9 above). Nonetheless, there is clear evidence that magnesium chloride is less toxic to lettuce seed than sodium chloride by the lower LD50 and overall root length increase. This conclusion is further justified given that less magnesium chloride is needed to maintain the same level of service as sodium chloride and therefore, less will enter the environment.

Because CDS is increasingly being patented as an anti-icing application for crops, it was also tested on lettuce seed to determine if there were benefits associated with the fertilizer effects as reported by patent holders. Seeds sown in 1:4 solution of CDS and distilled water did not produce significant germination (only 30%) or radical length (≤ 22mm) after 5 days as shown in Figure 12. Results from another series of tests on calcium chloride using filter paper were observed to promote bacterial growth, likely due to contamination during handling as is evident by the colony formations as shown in Figure 13.

Perhaps more interesting is the dark brown spot at the bottom of Figure 13. After 3 days of incubation, there were still no seeds germinated nor any visible signs of coliform units forming. Still, the test was considered a failure at this point, but allowed to progress with a fresh drop of straight CDS placed over one seed in order to examine if it would promote growth and study the effects at the end of the 5 days. Apparently, it is the healthiest seed having germinated and is free of bacterial growth in the vicinity of the spot.

Also noticeable is the lighter color at the center of the CDS drop. At this point, the radical penetrates the paper and is where the transport layer forms between paper and root. It is hypothesize that the lighter color indicates the root is taking up nutrients from the CDS and effectively removing it from the substrate. It is further hypothesized that CDS has antiseptic or herbicidal properties and although not well understood, might explain why it produces low germination rates in seeds, perhaps by chemically interfering with enzyme functions at the germination stage or by disrupting osmosis across the transport layer, yet serve as a plant nutrient and antiseptic agent in other respects. In one application [d8], CDS was used as an herbicide and a fertilizer in the use of crop production and showed it to also be part of an effective mitigation strategy in weed control.

TOXICITY TO BACTERIA
This study is designed to evaluate the effects of a stream containing CDS might have on bacteria such as that found in and an activated sludge process or a specialized population of organisms. Towards this goal, a rapid toxicity test was employed using PolyTox™ [d6] standard inoculums on samples of CDS at various concentrations. PolyTox™ is a standard preparation of surrogate microbial cultures and nutrients which allows for a simple and economical testing.

The process evaluates the inhibitory effects of different concentrations by measuring the respiration rates of standard aerobic bacterium. The respiration rate or DOUR (Dissolved Oxygen Uptake Rate) is the oxygen consumed by the aerobic bacterial cultures and is expressed in mg of oxygen per liter per minute. Deionised water was aerated for 1 hour prior to testing and continuously throughout the experiment (Figure 14). At the same time a saturated solution of distiller’s grains was prepared by soaking 200g of DDGS in 400ml of DI (Deionised) water with stirring and gentle heating for 1 hour to produce a 5 to 10 percent solids aliquot after settling. A baseline (DOURS) of DI water and PolyTox™ was conducted to account for any oxygen depletion caused by the PolyTox™ population standard.

Additionally, a background sample (DOURB) without PolyTox™ was run to account for oxygen depletion caused by either microbes present in the sample or by the stripping away of COD during aeration. Finally, test solutions (DOURT1 and DOURT2) of 33% & 66% by volume CDS were prepared and run to determine the actual DOUR (dissolved oxygen uptake rate) of the samples. Raw data and calculations are included in Appendix A, Figure 14 to 16 and tabulated in Table 9 below.

Dissolved Oxygen Uptake Rate (mg/L/min)
DOURS	0.1
DOURB	0
DOURT1	0.1
DOURT2	0.1
DOURC1	0.1
DOURC2	0.1
% Inhibition #1	0
% Inhibition #2	0

The recorded DOURS value of 0.1mg/L/min. was lower than expected; 0.20 to 0.50mg/L as recommended by the supplier’s application procedure. However, the instrument used (Sartorius Oxygen Meter, Model TE3102S, Figure 15) did not provide sufficient precision and therefore, actual results may be higher than reported. Nonetheless, calculations show that DDGS remains nontoxic at concentration levels much higher than anticipated for design.

Figure 16 is a plot of dissolved oxygen in the presence of microbial inoculums and nutrient over time showing a marked reduction in O2 levels immediately following the addition of DDGS which increases with concentration, while the rates at which oxygen is depleted remains the same independent of the concentrations used. Perhaps more interesting is the zero oxygen uptake rate of the DOURB run, further indicating an absence of native microbes or COD (Chemical Oxygen Demand) compounds in the specimen.

Despite the lack of instrument precision, exponential best fit plots were selected based on confidence after trying various methods in addition to linear, log, and polynomial fits in Excel.

While there is very little variance in the standard and test runs (R2 ≥ 0.99) predicted by the curves, the background parameter (DOURB) is not well defined (R2 = 0.54). It is observed that there was a marked increase in DOURB during the initial minutes and it is believed an observed air bubble trapped under the sensor was the cause. Assuming the DOURB is in fact 0.00 mg/L/min, the model predicts zero percent inhibition of CDS specimens. Based on these findings there would not appear to be significant inhibitory effect on biological systems or processes caused by CDS at pragmatic design levels, however, the lack of instrument precision and level of expertise preclude any concrete evidence to support this claim without further testing under more appropriate conditions.

FIELD TESTING
The objective of this section is to empirically determine field effects and resolve operational performance issues associated with the use of CDS and co-products. Where applicable, brines were prepared using specimens obtained from the Ville-Marie stockpiles.

Solution 1 (Figure 17 - Left) is a control solution of sodium chloride prepared by dissolving about 140g of rock sourced from the Ville-Marie stockpile into 400ml of water. The stockpile contained about a 9:1 mix of rock salt to gravel and although the gravel fraction was screened from the test specimen, suspended particles are observed to impact a light grey color and opacity to the brine.

Solution 2 (Figure 17 – Middle) is a mixture of 1:4 CDS (A) and calcium chloride solution (D). Immediately evident is the dark color imparted by the high solids content of CDS, which improves the albedo effect during daytime and heat retention at night.

Solution 3 (Figure 17 – Right) is a mixture of BlueFuzionTM prepared similarly to solution 1. The blue dye impacts color to the solution which also improves albedo, however, after standing for a few hours, the blue dye component is seen to settle out with the gravel dust (Figure 18), likely having sorbed to the suspended particles, whereas solution containing CDS do not settle out.

ANTI-ICING
A simple set up consisting of 61cm by 61cm concrete patio blocks were placed end-to-end on the ground at a slight incline (Figure 18) and brines were applied to each block before a snow event along with a control receiving no application. The blocks and solutions were set out 12 hours ahead of anticipated precipitation and subsequently coated with solution using spray bottles, then allowed to stand while precipitation fell. Figure 19 shows the surface layer of liquid formed shortly after application.

Straight sodium chloride (left) is observed to have formed the least amount of film. Moreover, some areas quickly dried out or the liquid simply drained away and more solution had to be applied to obtain an effective cover. Solutions of BlueFuzion™ (center) and CDS with calcium chloride (right) provided much better cover and although faint; a tinge of blue imparted by dyes in BlueFuzion™ and brown from the solids in CDS are discernable.

The blocks were inspected (Figure 20) and it was observed that while only a few mm of snow had fallen, blocks receiving anti-icing agents had no snow accumulation while the control, having not received any treatment, still had cover. Most evident is the column of liquid remaining on the block applied with BlueFuzion™ (second from left), however, it should be noted that CDS does form a cake when air dried (Appendix A, Figure 17) which is likely to provide greater friction on some surfaces. Moreover, CDS is observed to be less mobile than saturated salt solutions (Appendix A, Figure 18) as determined by a blot test and therefore, is less likely to funnel off inclined pavements.

Tip blockage was frequently encountered with the solution containing CDS and had to be flushed before continuing by shaking the spray bottle to dislodge particles at the bottom end of the screen. Moreover, foam was generated using this technique and it is hypothesized that the extra pumping effort and reduced pathway in the spray tip causes the lighter fractions of CDS to be squeezed out of solution and entrained with air. It should be noted that the spray tip of the bottle is somewhat different than a nozzle and would generally have a higher friction coefficient and more turbulent flow. Nonetheless, the frequent jamming further points out the importance of proper viscosity adjustments and the added level of care required during preparation by end users in order to avoid clogging of hoses, valves, connectors, pumps, and related equipment.

SUMMARY
Due to the hygroscopic/exothermic nature of magnesium and calcium chlorides, eutectic compositions and freezing point depressions are substantially better than other alts examined, and have been shown to produce better performance (gram for gram) than sodium chloride in particular, making them suitable as co-products with CDS in anti-icing/de-icing programs. The addition of CDS is shown to substantially reduce the alkalinity of brines and improve anticorrosive properties. The addition of CDS imparts a concentrated dark brown color to the solution that does not bleed out and will likely be effective at increasing albedo particularly as a stockpile pre-treatment. Similarly, the high solids content of CDS provides additional thermal protection to brine solutions by allowing them to retain more heat thereby remaining effective longer. Moreover, pre-wetting with a higher solids content equates to more mass on the salt crystal and therefore deeper penetration into snow cover.

Solutions of CDS as high as 50% solids have a freezing point well below -13° C (as tested), are free flowing, and readily soluble in water. When CDS is combined with traditional chlorinated deicers, the synergistic effects are observed to substantially increase the performance of brine solutions by providing more melt capacity, penetration depth, extended working time and temperatures, as well as aiding in prevention of the “slickness” period that occasionally occurs with chloride brines and magnesium chloride in particular.

Because CDS can be applied in solution form by itself or mixed with co-products, tighter quality control, ease of use, and more even applications can be achieved. It can be sprayed using conventional spraying equipment upon most surfaces, applied onto accumulated ice at ambient temperatures or can be heated before its application to allow for even lower working temperatures. Due to its viscous nature, comparatively small amounts are required as it tends to remain in place and is not easily blown away by the wind or action of passing traffic. Furthermore, since less material will leave the roadway, residual deicing effects can be expected between applications. Viscosity can be controlled by dilution or as some proponents claim, adjusted by pH, however, care must be taken by end users to ensure adequate equipment and handling procedures are followed in order to maintain smooth operation while providing adequate service levels.

A second consideration relating to spray applications is the moisture content of CDS compositions that can be used in admixtures with salt, sand or gravel, cinders, sawdust, or other skid-reducing agents, subsequently applied to roadways or other surfaces. In these cases, the application rates to said substrate are likely controlled by the moisture content of the CDS solution and the hygroscopic nature of the substrate. It is hypothesized that higher CDS solids content and/or viscosity of the solution would provide more effective cover on solid stockpiles by limiting the moisture content and subsequent salt losses due to leaching, while allowing for adequate ratios of CDS to co-product salts, in order to remain effective as a pre-wetting agent.

Compositions of CDS have been shown to be neither overly corrosive nor environmentally unacceptable. This is a significant advantage over inorganic deicers which are shown to damage infrastructure and the surrounding environment. Furthermore, CDS is a biodegradable substitute for inorganic salts, in particular, sodium chloride, where it is observed to be as effective at melting and penetrating ice. By the same token, the addition of CDS to brines provides mitigating measures towards enhancing vegetation along roadways while showing no ill-effects on bacterial cultures found in waste water streams.

RERERENCES
[d1] C. H. Choi, D. S. Chung, P. A. Seib and K. M. Chung,”Effects of Brewers’ condensed solubles (bcs) on the production of ethanol from low-grade starch materials”, Journal of Applied Biochemistry and Biotechnology, Volume 50, Number 2, Page 175-186, Feb. 95

[d2] American Society of Civil Engineers (ASCE) , “Summary of Evaluation Findings for the Testing of Ice Ban “, Nov. 98

[d3]National Concrete Pavement Center, “Development of an Improved Agricultural-Based Deicing Product”, Page 45, Jan. 10

[d4] Ecological Effects Test Guidelines OPPTS 850.4200 Seed Germination, EPA, 1996, http://www.epa.gov/opptsfrs/publications/OPPTS_Harmonized/850_Ecological_Effects_Test_Guidelines/Drafts/850-4200.pdf

[d5] A Study of Dust Suppressants in Ontario – Final Report, Ontario Ministry of Environment and Energy, 1993, http://ia331416.us.archive.org/1/items/studyofdustsuppr02torouoft/studyofdustsuppr02torouoft.pdf, p14

[d6] InterLab, PolyTox® Application Procedure, 2007, http://www.polyseed.com/applproc/Polytox%20Application%20Procedure.pdf

[d7] SEBCI Inc.,”MSDS Blue-Fuzion”, Jan. 2008

[d8] Blume, David (534 Lattouda Dr., Aptos, CA, US), US Patent 7183237, http://www.freepatentsonline.com/7183237.pdf

Footprint Analysis: A Measure of Lifestyle

2010-02-13T07:15:00.011-05:00

According to a recent publication from the World Wildlife Federation, if a “business as usual” approach continues to dominate the mentality of prosperous nations, society as a whole may find it increasingly difficult to affect meaningful change other than responding to unanticipated environmental calamities brought about as a consequence. Even more alarming, experts believe by 2050 accumulated ecological damage may be irreversible unless we manage to alter our self-destructive course in time. [b]

So it is no wonder that today’s green lifestyles have developed beyond concept into doctrine, finding their way into our hearts and politics. Yet while concerns about environmental degradation, resource shortages, and human health impacts are promoting widespread acceptance of a sustainable lifestyle, more can be done to aid the day-to-day practitioner towards mitigating the enormous pressures on planetary ecosystems caused by human activities.

Towards these endeavours, the concept of a sustainable lifestyle, which ultimately aims to minimize natural resource consumption and impact on ecological systems, is presented in a familiar context. In particular, a Canadian ecological and detailed water footprint are put forth as examples of consumption patterns of first and third world nations in comparison to global averages.

Ecological Footprint

Originally developed by William Rees and Matthais Wackernagel in 1994 [c], the ecological footprint quantifies the area of biologically productive land and water used to supply human resource needs (crops, fish, meat, forest products, energy and built-up lands) and to absorb its wastes. An ecological footprint is expressed in global hectares (gha) or global acres (ga) and is broken into four consumption categories: carbon (home energy use and transportation), food, housing, and goods and services. The ecological footprint can also be broken down into four ecosystem types or biomes: cropland, pastureland, forestland, and marine fisheries.

The carbon footprint is the area needed to absorb carbon emissions generated by home energy use and transportation. The food footprint includes the area needed to grow crops, fish, graze animals, and absorb carbon emissions from food processing and transport. The housing footprint includes the area occupied by your home and the area needed to supply resources used in construction and household maintenance. The goods and services footprint includes the area needed to supply consumer items and absorb carbon emissions from their manufacture, transport, and disposal.

Figure 1 below shows the global average per capita ecological footprint in hectares by consumption categories. Figure 2 shows the relative impact on respective biomes.

Figure 1

Figure 2

There are only 15.71 global hectares available per person on a renewable basis, however, present day society as a whole consumes 23.47 hectares which indicates we are overshooting the Earth's biological capacity by nearly 50%. In other words, to sustain present levels of consumption, we would need 1.5 earths. As we will examine, affluence and technology appear to be the leading indicators of a larger ecological footprint. How is it, for example, that the ecological footprint of North America is 1.8 times larger than our available bio-capacity while by comparison, South America’s footprint is only 50% of its bio-capacity.

My Ecological Footprint

As a Canadian, I’m reluctant to admit we use more energy per capita than any other nation in the world and although we have plenty of cheap, renewable electricity, it’s wasteful, both in cost to the environment and the long term tradeoffs to society. As an environmental engineering undergrad and day to day practitioner of sustainable living it should be no surprise however, that our household’s ecological footprint averages roughly half the nations’. (see figure 3) Furthermore, there are several mitigating factors we employee to reduce our total footprint at home such as pet waste composting, vermicomposting, LED lighting, and low power electronics to name a few and which are likely unaccounted for in the quiz. As further examples; our goal is to divert 90% of household and pet waste from the curb by the end of 2010 and we regularly design and implement low voltage circuitry into our home and personal electronics, something not everyone is aware they can practice daily with composting at home or a little background knowledge of the technology at hand. [d]

Figure 3

Figure 4

Yet despite serious efforts to reduce our footprint to sustainable levels, our household still consumes more bio-capacity than the global average and nearly 4 times that of a Bolivian.

Bolivian Ecological Footprint

Bolivia is predominantly rural and is one of the least-developed countries in South America. Almost two-thirds of its people, many of whom are subsistence farmers, live in poverty. The typical diet is abundant in carbohydrates but deficient in other food categories including wheat which must be imported and meats which are reserved for ceremonial occasions. Silver mining and agriculture in the highlands have historically been the twin pillars of the economy with the nation traditionally producing and exporting raw materials while importing manufactured and processed goods. Demographic data for Bolivia from 2005 was used to complete the quiz. [e]

Figure 5 shows that based on a Bolivian peasant’s lifestyle, we would only require 0.38 earths. Clearly this is a sustainable lifestyle, but it comes at a price. Bolivians peasants have shorter life expectancy, higher infant mortality rates, and a harder way of life for example.

Figure 5

Figure 6

Why such a disparity between ecological footprints?

Various reasons exist for the disparity amongst nations such as affluence and technology and even from person to person within a nation (perhaps due to the level of awareness). Colder northern climates require more energy for heating, lighting, and cooking, whereas hot and humid climates require more energy for cooling and refrigeration. Statistically, however, there is a strong correlation between coldest temperature areas and energy consumption. Moreover, many of the industrialized nations are in northern climates, and therefore, it is no wonder Canadians simply require more energy.

Substantial energy and material resources are expended on the construction and maintenance of conventional buildings. As of 2006, buildings consumed 40% of the total energy consumed in both the US and European Union. (Wikipedia) As shown in figure 7, buildings use 70% of the total electricity consumed, 12% of the total amount of potable water consumption per day, and 40% of raw material usage. Furthermore, 39% of the total carbon dioxide and 30% of waste output can be attributed to buildings. (USGBC) Moreover, buildings often result in environmental degradation such as loss of amenity and biodiversity which are much more difficult to assess. [d] By the same token, carbon emissions are generally highest for households living in newer suburbs due to the increase energy requirements for public infrastructure, housing, and both personal and commercial transportation. In rural areas such as Bolivia, there is a greater self reliance on local food, energy, and water resources. Likewise, fewer short trips on congested roadways lead to lower energy requirements relative to sprawling suburbs.

Water Footprint

When compared to other natural resources such as land and energy, little research has been carried out in the area of water when it comes to the assessment of resource used in relation to consumption patterns. To close the gap, the water footprint concept was introduced by Hoekstra and Hung (2002) in order to have a consumption based indicator of the cumulative virtual water content of all goods and services consumed by one individual or by the individuals of one country. It has been estimated that the Global average water footprint is equal to 1243 m3/cap/yr or about 3000 L/cap/day. [f] Like the ecological footprint, the water footprint takes into account the three main factors of consumption; food production, domestic and industrial uses.

For food crops, the footprint includes; water used in growing the crop, water used in washing and processing and water used at the consumption stage (washing and cooking). The water footprint can be further divided into three components: Green water or rain water used at the point where it falls. Blue water or the net volume of water abstracted from rivers, lakes and groundwater (including mains water, reservoir storage and direct abstraction) used by the crop. Grey water or the volume of freshwater required for diluting return flows (drainage and runoff) to an agreed, acceptable quality standard.

Domestic fresh water consumed in households requires energy for both delivery and treatment. Household water use also takes water from other beneficial uses such as irrigation or in-stream flow for fish and wildlife. The water footprint of a product (commodity, good or service) is the volume of freshwater used to produce the product, measured at the place where the product is actually produced. It is very difficult to assess the water footprint of specific industrial products for the simple reason that the diversity of industrial products is immense and that production chains are complex and different between nations and companies. For example it is estimated that the global average water footprint of industrial products is 80 litres per US$. In the USA, industrial products take nearly 100 litres per US$. In Germany and the Netherlands, the average water footprint of industrial products is about 50 litres per US$. By comparison, industrial products from Japan, Australia and Canada take only 10-15 litres per US$. [g]

My Water Footprint

Our water consumption goes beyond food, washing and keeping our lawns green. In fact, water plays a role in everything we produce, use, and consume. Moreover, we tend to live in sterilized environments which often require copious amounts of water resources for dilution and waste removal. Consequently, we have higher industrial and domestic water requirements. However, as seen in figures 8 and 10, the major component of water usage is directed towards diet. In fact, the agricultural and ethnic richness of Canada has led to two distinctive characteristics of everyday food consumption. The first is its scale. Canadians are hearty people and we eat hearty portions, with meats being the dominant group. For example, pork can figure in each meal; Pork at breakfast may appear as bacon, or sausage. At lunch, pork may appear in a sandwich in the form of processed meats. For dinner, pork appears in large and more highly valued forms, such as roasts or hams, which often require more elaborate preparation and presentation in a way that highlights their value and size. By comparison, Bolivian peasants eat little to no pork.

The other main feature of Canadian food consumption is diversity (figure 9). The complex ethnic landscape of Canada and the tendency of ethnic groups to retain a dual cultural orientation have meant that Canadian cuisine is quite diverse in its content requiring items to be transported from far and abroad adding to the carbon footprint and water resources of other nations.

Bolivian Water Footprint

As are global water consumption patterns, food production remains the most important factor in Bolivia’s water footprint. Not surprising, is that most rural homes do not have running water or plumbing. Furthermore, while certain Third World nations are experiencing major industrial growth, others however, such as Bolivia are not.

The typical Bolivian peasant diet is abundant in carbohydrates but deficient in other food categories (see figure11). In the highlands, the primary staple is the potato, followed by other Andean and European-introduced tubers and grains, maize, and legumes, especially the broad bean. Freeze-dried potatoes (chuño) and air-dried jerky (ch'arki) from cattle or camelids are common, although beef forms an insignificant part of the daily diet. [h]

Consequently, Bolivia has a considerably smaller water footprint than that associated with a First World nation such as Canada. However, closer inspection of the results indicates that Bolivian still uses 3 times more water per capita for food in relation to domestic consumption compared to Canada. The domestic consumption for the most part is due to available sanitation and technology missing in Bolivia. Furthermore, agricultural practices in First World countries tend to increase growing capacity and efficiency, thereby requiring less water. As a consequence, Bolivia’s higher food requirements are likely a reflection of inefficient farming practices.

The Role of Food

The water needed to produce a nutritionally acceptable diet for one person can be 60 times as large as the amount needed for domestic water supply as is the case for Bolivia. Likewise, global industrial water use is 720 cubic kilometres per year, which is only 10 % compared to the global water use for crop production. Globally, it has been estimated that up to 18% of all greenhouse gas emissions are associated with animal consumption, whereas a plant-based diet is significantly less land and energy intensive [i]. Furthermore, meat production drives deforestation and requires high inputs of energy for processing and transportation, driving up the carbon footprint price tag. As is the case for Canada, two important footprint variables are food miles (or miles to market) and the amount of processing and packaging. As a diverse and prosperous culture, Canadians’ have a palate for exotic foods and can afford out of season produce imported from across the world in highly process or packaged fashion, adding to the energy requirements for transportation, refrigeration, and disposal. By contrast, Bolivians buy fresh local foods from farmers markets or grow their own which help to reduce their footprint significantly and lend to the notion of a sustainable lifestyle, albeit less efficient and possible not meeting nutritional requirements.

Conclusion

The ecological footprint provides reliable estimate of sustainability. When a society's footprint tends to be larger than its available bio-productivity, it becomes unsustainable unless it appropriates bio-capacity from others, often leading to social and political, in addition to environmental injustices. In comparison, the water footprint highlights the importance of food in the bio-capacity equation of sustainability and reveals however, that poorer nations tend to require more water for this purpose when compared to industrialized counterparts. And while footprint methods are still evolving to include accounting of pollution and unsustainable resource management, it is likely that these measures underestimate our demands on nature.

To help mitigate resource shortages, a growing number of organizations are beginning to sell carbon offsets with the money going towards projects that reduce carbon emissions such as renewable energy and forest protection to name a few. These are voluntary measures and it is more likely the Canadian provinces will follow Quebec’s lead of a carbon tax imposed on energy producers which came into effect in October 2007 and with revenue collected going towards energy-efficiency programs including public transit.

Still, more can be done towards reducing our footprint and concomitant impact on nature and society. Nowhere is this more evident than in the disparity between Canada and Bolivia, both in demographic and environmental injustices caused by the divergent requirements between lifestyles. Like many poor cultures in the world, Bolivian peasants aren’t afforded the choices we Canadians enjoy and it is therefore our duty to provide leadership in sustainability while reducing our demand beyond the scope of our boundaries.

References

[a] Why Do Civilizations Fail, Feb. 2010, http://www.learner.org/interactives/collapse/
[b]Business As usual – Demand Grows Faster Than Supply, WWF, Feb. 2010,http://www.panda.org/about_our_earth/all_publications/living_planet_report/footprint/scenarios/business_as_usual/
[c] Rees, W.E., and Wackernagel, M.: 1994, "Ecological footprints and appropriated carrying capacity: measuring the natural capital requirements of the human economy," In A. Jansson et al., Investing in Natural Capital: The Ecological Economics Approach to Sustainability, Washington, D.C., Island Press.
[d] Rush, David, EcoEngineering, http://eco-eng.blogspot.com
[e]Boliva Demographics, Learner.org, Dec. 99, http://ww2.unhabitat.org/habrdd/conditions/southamerica/bolivia.htm
[f]Canadian Water Footprint, waterfootprint.org, Feb. 2010, http://www.waterfootprint.org/?page=cal/waterfootprintcalculator_national
[g]Industrial Water Footprint, waterfootprint.org, 2010, http://www.waterfootprint.org/?page=files/productgallery&product=industrial
[h]Boliva – Country and Culture, everyculture.com, 2010,http://www.everyculture.com/A-Bo/Bolivia.html
[i] Vital Signs: The Trends That Are Shaping Our Future, http://books.google.ca/books?id=qBhoziIy3M4C&client=firefox-a&source=gbs_navlinks_s

Global Worming

2009-12-02T14:02:00.009-05:00

Charles Darwin’s final book, entitled "The Formation of Vegetable Mould, Through The Action of Worms, With Observations On their Habits" (1881), made aware the great importance of earthworms in the breakdown of organic matter and their release of nutrients to the surrounding soil. Included in this work is a quote that emphasized his respect of earthworms;

Although the conclusion may appear at first startling, it will be difficult to deny the probability that every particle of earth forming the bed from which the turf in old pasture land springs, has passed through the intestines of worms.

Yet it was necessary to wait almost 100 years until Darwin’s notion of worms was adopted by the environmental engineering community and their application towards waste management technologies began to root. More recently, vermicomposting has been implemented to successfully process sewage sludge and solids from wastewater, materials from breweries, paper wastes, urban residues, food wastes, and animal wastes as well as horticultural residues from industrial processes.

Vermicompost is the excreta of earthworms, which is rich in humus and essential plant nutrients. Vermicompost improves soil structure, texture, aeration, water retention, and prevents soil erosion. Additionally, vermicompost is rich in cellulose decomposing micro flora and phosphorous solubility agents which further improve the soil environment. Vermicompost is free from pathogens, toxic elements, weed seeds and minimizes the incidence of pest and diseases when compared to traditional composting methods. Nonetheless, while vermicomposting can be practiced cost effectively in outdoor windrows using batch or continuous flow processes, more efficient, higher yield methods require continuous maintenance and monitoring in addition to acquired skills depending on available feed stocks and environmental conditions.

VERMICOMPOSTING REQUIREMENTS

Like other biological processes, the selection of worm species to colonize organic wastes naturally is dependent on; high rates of consumption, digestion and assimilation, ability to tolerate a wide range of environmental factors, high reproductive rates with short hatching time, and rapid maturation. Additionally, species should be strong, resistant, and survive handling. Of the 2700 species of worms, only a few possess all these characteristics with Eisenia fetida or red wiggler (Figure 1) being the most common species for management of organic wastes by vermicomposting.

Figure 1 - Red Wigglers

Compost worms like E. fetida have a specific range of environmental and ecological requirements that must be met for them to thrive; adequate bedding and a food source, moisture and aeration, as well as protection from temperature extremes and predators. Since worms breathe through their skin, aeration and moisture levels are necessary conditions for survival, therefore high absorbency bedding with good bulking potential is required. The bedding is consumed along with feed stocks as it breaks down, however high nitrogen levels can result in rapid degradation with concomitant heating, creating inhospitable conditions. In order to control overheating, bedding materials such as municipal paper waste (balanced C:N) and cardboard with much higher carbon content are generally found to slow the degradation process when mixed or by themselves and are considered good bedding materials for their absorption and bulking properties. A list of common bedding materials, absorbency and bulking properties, as well as C:N ratios is presented below.

Ideally, moisture-content in conventional composting systems is 50-60%, whereas ideal moisture-content for vermicomposting is 80-90%, with an optimum of 85% moisture. Moreover, the average worm weight in addition to other variables increased with moisture content. Worms can survive in moisture content down to 35% but will quickly die below this point, therefore, bed cover is usually provided to help retain moisture levels in addition to monitoring as required.

The actual amount of food that can be consumed daily by E. fetida varies with a number of factors including the state of decomposition of the food. Red wigglers will eat almost any organic material, however, beef and dairy manures are the most commonly used worm feed stock. Food sources such as manures consist of partially decomposed organic material which can be consumed more rapidly than fresh food, although pre-composted food stocks will have lower nutritional value than raw form. The general rule-of-thumb is that worms can manage half their weight per day. In addition to manures, other common feed stocks include fresh and pre-composted food scraps, human waste, grains from by-product, corrugated cardboard, as well as fish and poultry offal.

While composting worms do need oxygen, their requirements are relatively low. Worms are known to survive harsh winters inside windrows by living on the oxygen available in the trapped water, however they operate best when bedding material is well aerated. Through migration, worms aerate their bedding in addition to transporting materials or turning the bed, which is one of the major advantages to vermicomposting over conventional methods – Little or no additional aeration is required, even in static beds.

Composting worms are mesophilic and while Eisenia fetida can survive as low as 0ºC, it is generally considered necessary to keep the temperatures above 15ºC for efficiency. Composting worms will not reproduce below 10ºC, however cocoons can survive extended periods of deep freezing and remain viable for years. Compost worms prefer a temperature range in the 20s (ºC), but can survive up to the mid 30s (ºc). Temperatures above 35ºC are lethal and will cause the worms to leave the area if possible.

There are other important vermicomposting parameters including pH, salinity, urine, toxic substances, diseases, and predators. Worms can survive in pH range of 5 to 9, however, worms prefer a pH of 7 or slightly higher with an optimal pH of 8.0. Bedding pH tends to drop over time. Alkaline feed stocks will tend to moderate pH towards neutrality, otherwise, the pH of the beds can drop well below 7. In the case where the food source or bedding is acidic, pH can be adjusted upwards by adding calcium carbonate.

Worms are very sensitive to salts and prefer salt contents less than 0.5%. Manure high in salt content may need to be pre-leached by running water through the material for a period of time. By the same token, manure from animals raised on concrete floors often contains excessive urine which should be leached before use. Excessive urine can react with chlorine gas to produce toxic gases in the bedding. Additionally, different feeds can contain a wide variety of potentially toxic components. Some of the more notable are de-worming medicine, detergent cleansers, industrial chemicals, pesticides, and tannins from trees, such as cedar and fir which have high levels of these naturally occurring substances.

While compost worms are not subject to diseases caused by micro-organisms, they are still subject to predation by animals, insects, and to a disease known as “sour crop” caused by environmental conditions. Earthworms are a natural food source for moles and birds and can be a nuisance if outdoor windrows are used. It can be prevented by putting some form of barrier, such as wire mesh, paving, or a good layer of clay, under the windrow. Centipedes eat compost worms and their cocoons. Ants and mites can consume the feed meant for the worms. Also red mites are parasitic to earthworms whereby they feed on the blood or body fluid from worms and they can also suck fluid from cocoons. In these cases, the best prevention is to make sure that the pH stays at neutral or above. This can be done by keeping the moisture levels below 85% and the addition of calcium carbonate, as required. Sour crop or protein poisoning is the result of too much protein in the bedding. This happens when the worms are overfed. Protein builds up in the bedding and produces acids and gases as it decays. Keeping the pH at neutral or above will preclude the need for these measures.

VERMICOMPOSTING METHODS

There are two common vermicomposting methods in practice using either batch or continuous flow-through reactors. Reactors can be constructed as windrows, bins or beds, and can be modified to operate in a combination of continuous or batch modes. In batch systems, the bedding and food are mixed on beds or windrows up to 18 inches deep, worms are added, and then left to consume the materials until the process is complete. By contrast, in continuous-flow systems, feed and new bedding are incrementally added to the top layers on a regular basis and composted materials are harvested at the bottom layers.

Windrows can be constructed to operate as either batch or continuous flow systems. In batch operations, static piles of mixed bedding and feed are inoculated with worms and allowed to stand until the processing is complete. Static windrows do not need to be turned, however, they do need to be covered to retain moisture and guard against pests and predators. In continuous operation, food is placed on top of windrows and covered. Eisenia consume food at the food/bedding interface then drop their castings near the bottom of the windrow. Over time, a layered windrow is formed, with the finished product on the bottom, partially consumed bedding in the middle, and the fresher food on top.

Like windrows, bins and beds can be set up to operate as either batch or continuous flow systems. In a batch process, material is pre-mixed and placed in the bin, worms are added, and the bin is stacked for a pre-determined length of time. Continuous operation is similar to a top-fed windrow, however, bedding is contained within four walls, a floor, and is protected to some degree from the elements by cover. Stacked bins address the issue of space by adding the vertical dimension to vermicomposting and alleviate pest and predatory losses, however bins must be small enough to be handled on a regular basis and more maintenance is required. Since its development in the 1980s, the flow-through concept developed by Dr. Clive Edwards in England has been adopted and modified by several companies in North America to successfully treat a wide variety of materials mentioned above. In the flow-through system, worms live in raised boxes. Material is added to the top, flows through the reactor, and is harvested out through the bottom through screens. Using this type of process, it has been demonstrated that a 1000 square foot surface area can process 2 to 3 tons of organic waste per day.

BENFITS OF VERMICOMPOSTING

In addition to much faster decomposition rates, there are several other reasons that make vermicomposting a preferable method over standard methods. With vermicomposting, there is little to no need of aeration or turning unlike conventional methods. The end product of vermicomposting has greater soluble nutrient levels as well as higher microbial populations when compared to traditional methods.

Vermicomposting can be practiced indoors and outdoors, and is well suited for both urban and rural areas making it a good choice for homeowners looking to divert their organic waste from landfills despite available space or climate. In fact, in our case study, 250g of worms were allowed to reproduce under ideal conditions until the population was doubled at which point, the colony was transferred into a hybrid batch reactor maintained under conditions conducive with higher metabolic rates. Consequently, the system is capable of handling roughly 250g of organic household waste per day. While this is slightly less than our household produces, mature worms are regularly harvested and transferred back into a reproduction bin with subsequent reintroduction of the hatchlings into the reactor once mature. Eventually, the reactor will be able to manage all of a normal household’s waste from organic kitchen scraps, pet hair, dryer lint, eggshells, and we are continuously finding new materials to introduce into the process.

On an industrial scale, vermicomposting has been practiced as an in-situ soil remediation process whereby worms mine heavy metals from the soil or treat hydrocarbon contamination. Additionally, vermicomposting has been effective at treating municipal bio-solids and wastewater as well being capable of processing animal manures and other by-products from paper, distillery, and others. What’s more, worms can destroy pathogens including salmonella and E-coli, as well as parasitic worm eggs without further treatment. It’s no wonder, as Darwin pointed out over a century ago, worms remain the most effective natural cleaning agent known and will continue to find new applications towards landfill diversion, climate change, and waste treatment problems to name a few.

Vermicomposting - Month 3

2009-11-25T21:49:00.035-05:00

While there are many more cocoons continuing to be produced since the colony was transferred to a smaller bin, after a few weeks of spotting the first new cocoons it was decided to to raise moisture levels and place the bin in a window sill each day to raise temperature a few degrees in the bedding. After several equipment and process modifications since starting vermicomposting, cocoons have finally begun to hatch.

Deicing Montreal

2009-11-22T11:52:00.005-05:00

This proposal aims to provide the design, implementation and operation of an environmentally sound anti-icing process that safely and effectively fulfills Montreal’s road management needs. This strategy would significantly reduce the amounts of chlorinated salts entering the environment, reduce operational and maintenance costs, help mitigate the current condition ailing Montreal’s infrastructure, and improve road safety, in addition to provide a better understanding on the fate of alternative designs on the environment. Deliverables for the project include but are not limited to:

Design specifications for alternative brine solutions.
Design specifications for equipment including storage and Real Weather Information Systems (RWIS) test platform.
Prepare Anti-icing Standard Operation Manual and training.
Prepare Life Cycle Estimates of alternatives.
Provide ecotoxicology estimates on priority species.
Start up and operational budgets. Timeline for Implementation.

The Problem with Salt

“Based on the available data, it is considered that road salts that contain inorganic chloride salts with or without ferrocyanide salts are entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or that constitute or may constitute a danger to the environment on which life depends. Therefore, it is concluded that road salts that contain inorganic chloride salts with or without ferrocyanide salts are ‘toxic’ as defined in Section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999)”. [100]

Loading

Road salts came into common use in the 1940’s as a melting agent for removing ice and snow. Driven by growing urbanization and increasing density of road networks, as well as changes in services levels requiring more “bare pavement” policies on roadways [101], total road salts usage and application rates have been on the rise in Canada since the 1970’s.

Figure 1 - Historical salt use by provincial agencies (Salt Institute, 1964-1983), Morin and Perchanok, 2000 [106]

Today, an average of 5 million tones of road salts are used each year as deicing agents on roadways in Canada [103], yet there are no federal regulations which directly govern levels of salt use, or salt concentrations in various environmental media. In fact, the only relevant national environmental standards, which relate indirectly to road salt in the environment, are the Guidelines for Canadian Drinking Water Quality, March 2001. The aesthetic objective having a maximum of 200 mg/L sodium and 250 mg/L chloride.[100] Using a conservative estimate of road salts usage in Montreal; approximately 70,000 tons of salt is applied each year which is fated for the St. Lawrence with a flow rate of 9000 m³/s around the Island, resulting in a steady flow concentration of less than 0.25 ug/L. Consequently, much of the salt fated for the St. Lawrence basin does not appear to be of immediate concern.

However, water bodies most impacted by road salts are small ponds and watercourses draining large urbanized areas, as well as streams, wetlands or lakes draining major roadways. Waters from roadways, patrol yards or snow dumps can be diluted to various degrees when entering the environment, resulting in chloride concentrations as high as 2800 mg/L in groundwater adjacent to storage yards, 4000 mg/L in ponds and wetlands, 4300 mg/L in watercourses, 2000–5000 mg/L in urban impoundment lakes and 150–300 mg/L in rural lakes.[102] While highest concentrations are usually associated with winter or spring thaws, elevated concentrations can still be measured in the summer, as a result of the travel time of the ions to surface waters and the reduced water flows.

In water, natural background concentrations of chloride are generally less than a few milligrams per liter, however, concentrations of chloride over 18 000 mg/L were observed in runoff from roadways and chloride concentrations up to 82 000 mg/L were also observed in runoff from uncovered blended abrasive/salt piles in patrol yards. Chloride concentrations in snow cleared from city streets can be quite variable. For example, the average chloride concentrations in snow cleared from streets in Montréal were 3000 mg/L for secondary streets and 5000 mg/L for primary streets in the winter of 1997-98. [104]

Pathways

Ultimately, all road salts enter the environment as a result of: storage at patrol yards, roadway application, and disposal of waste snow. Releases are therefore associated with both point sources (storage and snow disposal) and line sources (roadway application). Delisle and Dériger [105] reviewed the physicochemical and ecotoxicological characteristics of roadside snow and the different sources related to snow removal from roads and sidewalks.

Disposal of Waste Snow

Clearing of snow generally involves plowing snow to the side of the roadway. In cities, snow clearing can begin as snowfall reaches 2.5 cm, with the snow being pushed to the sides of streets and onto sidewalks. However, when there is considerable accumulation (more than 10 cm) or when necessary, snow is cleared and transported to various disposal sites (City of Montréal, 1998). [107] The physicochemical and ecotoxicological characteristics in relation to various snow disposal methods have been reviewed by Delisle and Dériger and can be grouped into three categories, as described below.

Methods for clearing snow from the roadway without transporting it to snow disposal sites typically involve plowing snow to the side of the road or blowing it onto land adjacent to the roadway. These methods are generally not effective in areas with a high land occupancy factor.

Removal and disposal of snow may be required when the accumulation of snow on or along roadways may hamper traffic or safety. As such, the quantity of snow to be removed and disposed of depends on the volume of snow and the extent of urban development. Given the large amount of snowfall in Montréal and the size and density of the city, about 11.258 million cubic meters of snow were brought to snow disposal sites during the winter of 1997–98 (Figure 2).

Figure 2 - Total volume of waste snow and salt used in certain Canadian cities [105]

Roadway snow can be transported to snow disposal sites where it melts and the meltwater is treated. This typically involves dumping snow at surface sites or in quarries where runoff is channeled to treatment facilities. Generally, snow disposal sites are located on impermeable or slightly permeable ground or must be equipped with a geotextile membrane. Some sites are also equipped with sedimentation facilities or are designed to direct the meltwater towards a wastewater treatment system . These sites should not be located next to watercourses that could be affected by runoff.

Pinard et al. (1989) characterized chloride concentrations in runoff from snow disposal sites. This study indicated that only 2% of the salt spread on city streets was present in meltwater from snow disposal sites, with most of the salt likely released to the environment from the roadway or roadside.[109] This concurs with Delisle and Leduc (1987), who indicated that chloride concentrations in roadside snow initially increase then decrease with increasing time. [110]

While the percentage of salt present in snow transferred to snow depots may be low (e.g., 2%), the concentration of chloride in runoff is still elevated. A study by Péloquin (1993) indicated that the average chloride concentration in meltwater from a snow disposal site was 414 mg/L. [111] Pinard et al. (1989) monitored chloride concentrations in runoff from a Québec City snow disposal site from April 18 to the end of June 1988. Concentrations in runoff ranged from approximately 100 to 1100 mg/L. [109] Concentrations were highest in the early sampling and gradually decreased throughout the spring.

Methods involving release to surface water without water treatment. This method of disposing of snow involves dumping snow directly into a waterway or onto its banks. Snow can also be dumped down sewer chutes that are not linked to treatment plants. This results in the release of waste snow and any contaminants to surface water directly (dumping into rivers or into the ocean), with some removal of large debris (dumping onto banks) or with possible dilution by stormwater (dumping into sewer chutes not linked to treatment plants).

Roadway Application

Salt is typically applied in either a proactive approach prior to ice or snow formation or as a reactive approach after the precipitation has bonded to the pavement. Anti-icing is the proactive procedure that involves applying material prior to snow or ice formation to prevent ice from forming on the pavement, resulting in less material usage and fewer snowplow trips than a deicing strategy. Deicing is the reactive snow and ice control strategy that involves applying material on top of a layer of snow or ice that is already frozen or bonded to the surface of the pavement. Once bonded to the pavement, ice cannot be removed by plowing, and salt must then be applied to break the bond by lowering the freeze point of water.

A spreader with a spinner is the most common way of applying deicers. A spinning circular plate throws the de-icer out in a semi-circle. Alternatively, a chute can distribute deicer in a windrow on the road, usually on the centerline for best performance. Spreaders can be equipped with automatic or ground-oriented controls, which automatically regulate application rates as truck speeds fluctuate and have proven effective in reducing waste chemicals. Different materials will spread at different rates at the same spreader control setting, so calibration is essential for controlling application rates and must be verified on a regular basis.

Pre-wetting techniques can be used to moisten the salt with brine solution with either on-board pre-wetting systems or by pre-treating stockpiles, to keep the salt on the roadway during applications. Pre-wetted salt clings to road, which minimizes non-target applications and uses less salt. Wet salt also works at lower temperatures (generally below -6ºC) by accelerating the production of brine.

Sand and other abrasives are often necessary when temperatures fall below the eutectic point of the saline solution to improve vehicle traction on snow and ice covered roads. Sand is the most common abrasive, but slag, cinders, and bottom ash from power plants are also used. Abrasives used for winter road maintenance can have negative impact on infrastructure, clogging storm water inlets and sewers. Cleanup may be necessary in urban areas, on bridge decks, and in ditches. The materials may wash downstream and end up in streams and lakes. Abrasives must be treated with salt to keep them unfrozen and usable whereas salt-treated abrasives can accelerate vehicle corrosion. Recent concern has been raised in areas with air pollution with particles less than 10 microns in size (pm 10) having been documented from winter abrasive use. [108] As a result, cleaner abrasives and quicker cleanup after the storm are being required in areas with severe air pollution problems.

Patrol Yards

Patrol yards (also referred to as storage yards or maintenance yards) are used to store road maintenance materials before their application to roadways. Patrol yards can be located in a variety of settings, and patrol yard design and standards vary substantially across Canada. Accordingly, the degree of protection against weathering varies considerably. Covered facilities used to store road salts can include domes/igloos, sheds and leantos. Doors or walls may or may not be present, and storage under an overpass can be considered as covered by some agencies. Salt may be stored on asphalt or concrete pads or outside on a thick plastic tarp and covered by another tarp.

A New Brunswick study (NB DOE and DOT, 1978) monitored the quantity and quality of leachate from a 2000-tonne abrasive pile with a 2.5% salt content. During the first year, 420 m³ of leachate passed through the monitoring system. Sodium and chloride concentrations in the leachate are depicted in Figure 4 below.

Figure 4 - Average daily concentration of leachate from salt-treated sand pile, 1975–76

Estimates of releases to the environment were made by Snodgrass and Morin (2000). Figure 5 below provides three estimates based on the following scenarios: A patrol yard with best management practices where salt and mixed abrasive piles are stored indoors; a patrol yard where salt piles are stored indoors and abrasive piles are stored outdoors; and a patrol yard here neither abrasive piles nor salt piles are stored indoors. Of the three scenarios, options 1 and 2 are probably most representative of patrol yards. [112] The last column of figure 5 estimates the percentage of total road salt use that may be lost at patrol yards. Depending on the facility and salt management options, 0.2–20% of total salt use can be lost at patrol yards.

Figure 5 - Estimate of magnitude of salt loss at patrol yards

Ville-Marie Case Study

Given the population density of Montreal (423 pers./km²), clearing snow from the roadway without transporting it to snow disposal sites is not feasible. Furthermore, the direct dumping of snow to fresh surface water is restricted and is not permitted in Quebec as of 2002 [104]. In the past, municipalities such as Montréal blew snow onto private property and occasionally used snow melters. Blowing onto private land was virtually abandoned by Montréal because of social and political pressure, and snow melters proved to be too expensive to operate because of fuel costs. Furthermore, in response to exceptional snow fall in 2002-03, Montreal instituted a strategic plan to improve snow removal operations in 2008-09. [113]

Disposal Methods

The 2008-09 strategic plan for snow removal operations is a coordinate effort among the 14 boroughs on the island which aims to; review the training plan for foremen and adapt it to snow removal operations, improve mechanic availability all winter long, prepare two temporary sites ahead of time, provide work on the Saint-Michel quarry and sewer chutes, and improve site performance.

Figure 6 - Ville-Marie Disposal Sites

As a result, Montreal currently uses 30 disposal sites to treat 13.5 million m³/year of snow collected: 13 snow dumps (49%), 16 sewer chutes (32%), and 1 dedicated quarry (19%). Figure 6 shows the relative location of chutes and dump sites available to Ville-Marie operations.

Storage & Application Methods

Ville-Marie currently stockpiles salt, sand, and gravel under the Ville-Marie Expressway located at its depot. Figure 7 shows stockpiles of gravel (left) and salt (right) left over from 2008 operations. Concrete walls and pads separate the materials and storage under the overpass is considered as covered. Each year over 120,000 tones of road salt and 13,000 tons of sand or gravel are dumped on Montreal’s streets which are fated to wind up in the environment or have negative impacts on infrastructure.

Figure 7 - Ville-Marie salt and gravel stockpiles

Materials are loaded by tractor into trucks equipped with a hopper and spreader for transport and application. Shown in the various figures below are pieces of equipment used by Ville-Marie for road operations. Montreal primarily uses 3 types of spreaders (figure 8-10) to distribute salt/sand/gravel mixes as outline in their operating manual; however, Ville-Marie does have the technology and equipment able to apply liquid agents as seen in figures 11-13. When temperature fall below -15º, abrasives (salt/sand) are mixed to produce friction on road surfaces where NaCl alone is ineffective. Show in figure 14 is a cave-in located within the Ville-Marie borough and is typical of the day-to-day operational difficulties being encountered with the city’s ailing infrastructure and increased use of abrasives. Particles are forced through the system by gravitational flow until an obstacle is encountered where they stock pile, resulting in a concomitant head loss in addition to abiding erosion and other adverse conditions.

Figure 8 - Ville-Marie spreader	Figure 11 - Ville-Marie shovel with spray nozzles
Figure 9 - Ville-Marie spreader	Figure 12 - Ville-Marie portable spray unit
Figure 10 - Ville-Marie spreader	Figure 13 - Ville-Marie tanker truck

Figure 14 - Ville-Marie pipe burst and cave-in

Proposed Solutions

While it is true that current salts usage has taken its toll on Montreal’s ailing infrastructure, it is easy to foresee that a properly designed anti-icing process will alleviate the need for abrasives all together and therefore work towards mitigating the growing infrastructure problems. Moreover, due to concerns about the large quantities of chlorides being released to the environment, road salts underwent a comprehensive five-year scientific assessment under the Canadian Environmental Protection Act, 1999 beginning in 1995. The study was in reaction to a U.S. Salt Institute study which was deemed unreliable enough for Canadian climates. The road salts assessment covered the chloride salts; sodium chloride (NaCl), calcium chloride (CaCl₂ ), magnesium chloride (MgCl₂) and potassium chloride (KCl) , as well as brines used in road de-icing/anti-icing. [114]

This study produced two pieces of documentation; Salt Management Guide and Syntheses of Best Practices, which provides guidance available to users of road salts in Canada. Summarized below are the keys issues relating to the reduction of salt impacts in Montreal.

Patrol yards: Measures and practices should therefore be considered to ensure storage of salts and abrasives to reduce losses through weathering, to reduce losses during transfers and to minimize releases of stormwater and equipment washwater.
Roadway application: The selection of alternative products or of appropriate practices or technology to reduce salt use should be considered while ensuring maintenance of roadway safety.
Snow disposal: Measures to minimize percolation of salty snowmelt waters into soil and groundwater at snow disposal sites should be considered. Measures should also be considered to ensure sufficient dilution before release.
Sodium chloride pre-wetted with calcium chloride brine has been recommended for reducing total salt applications. [115]

Pre-Wetting

There are tremendous benefits to the pre-wetting technique, most notably the quick response in deicing, reducing salt use, and controlling non-target applications including the bouncing of dry salt on roads during application, wind, or traffic, however, there are other factors to consider when using this method. These include additional equipment for liquid storage and secondary containment, truck mounted on-board pre-wetting equipment and dependable maintenance procedures to prevent equipment corrosion, clogging, and seizing. Figure 15 shows a list of common substances along with critical parameters. While any liquid de-icing chemical can be used to pre-wet, liquid calcium chloride is used widely. Applications of 40 L/m³ are recommended.

Figure 14 – Physical/Chemical properties of salts

Using salt brine to pre-wet is becoming more common because of its lower cost. Some agencies are producing their own salt brine solution from existing stock piles or turning to alternatives such as liquid calcium chloride and magnesium chloride. Additionally, new uses for by-products are finding their way into the mix. Several patents in the U.S. have designed new products which can be applied to existing stock piles. By-product from local waste streams are blended with magnesium chloride or calcium chloride to produce a liquid which can be applied directly to salt piles or during application though spray nozzles.

While some agencies spray the salt as it is loaded into the truck, the application is more uniform if truck-mounted equipment is used to spray the salt as it leaves the spreader. This also eliminates the problem of handling pre-wetted salt that is not immediately used. Traditional snow and ice control practice like Montreal’s is to wait until an inch or more of snow accumulates before beginning to plow and treat the roads with chemicals and abrasives. While this procedure is straight-forward, it frequently leads to a compacted snow layer (pack) that is tightly bonded to the pavement surface. A subsequent "deicing" of the pavement is then necessary, usually requiring a large quantity of chemical to work its way through the pack to reach the snow/pavement interface and destroy or weaken the bond. Because this operation is reactionary, it requires less judgment than anti-icing. Yet as a result of its inherent delay, it often provides less safety at higher cost. Nonetheless, the reactive technique of deicing will remain important for snow and ice control, as there will always be conditions that preclude preventive operations such as higher priority routes during storm events or heavy precipitation.

ANTI-ICING

Application of deicing agents onto roadways at the start of or prior to winter precipitation inhibits the development of a bond between the snow or ice and the pavement surface. Moreover, less concentrated and periodic reapplications of the chemical during precipitation will continue this effect. In fact additives such as beet derivates and distillers grains can decrease the bounce and increase stickiness, which promote build on road surfaces.

Preventive operations are the core of an anti-icing program that provides a maintenance manager with two major capabilities: maintaining roads in the best conditions possible during a winter storm, and to do so effectively. Anti-icing has the potential to provide the benefit of increased traffic safety at the lowest cost. However, to achieve this benefit the maintenance manager must adopt a systematic approach to snow and ice control and must ensure that the performance of the operations is consistent with the objective of preventing the formation or development of bonded snow and ice. Such an approach requires use of considerable judgment in making decisions, requires that available information sources be utilized methodically, and requires that the operations be anticipatory or prompt in nature.

As such, anti-icing is better suited to routes with a higher level of service. This is because the vigilance and timeliness of successful anti-icing operations are most compatible with service levels requiring earlier and higher frequency winter maintenance operations. It is also because the preventive nature of anti-icing can support higher service level objectives such as maintaining bare pavement throughout a storm or returning to bare pavement as soon as possible following pack formation. In fact, because of the demanding requirements of higher service levels, many maintenance forces in Montreal have been instinctively implementing elements of anti-icing practices for years and boroughs around the island have instituted successful anti-icing programs. [116]

The Insurance Corporation of British Columbia (ICBC) has recently produced a guideline entitled “Proactive Guide to Snow and Ice Control: A Guide for Highway Winter Maintenance Personnel,” which provides a comprehensive description of anti-icing application techniques which provide maximum road safety at minimum cost.[e] At the end of a two year study conducted by the ICBC, it was found that there was a reduction in the number of collisions by up to 73% on pre-treated sections, the total accident claims for the entire jurisdiction under study were reduced by 6% on snow days, resulting in an estimated savings of up to $600,000 per winter to ICBC.[117]

In accordance with these guidelines, an effective winter maintenance program consists of several elements with varying degrees of importance depending on the size of the operational jurisdiction it covers and the complexity of its road network. One element, level of service (LOS), is important for all jurisdictions and must be considered along with the climatic conditions in the design of any snow and ice control program. Figure 16 depicts the components of an anti-icing program in the context of a winter maintenance program and the LOS assignments.

Figure 15 - LOS assignments for a winter maintenance operation

In addition to the service level, maintenance effort will vary with climatic conditions. Pavement temperature directly influences the formation, development, and breaking of a bond between fallen or compacted precipitation and the road surface as well as the effectiveness of chemical treatments and is therefore an important factor to monitor. It is also important when high humidity levels are accompanied by low dew point temperatures. Under these conditions there will be a greater potential for formation of frost and black ice. Unless some external source of heat is provided, the pavement temperature will generally track air temperature with a time delay. For road sections without obstructions to a clear sky view, higher solar radiation and exposure to the clear night sky will affect the road surface temperature to a greater extent than sections influenced by air contact only. Other important climatic factors are type and rate of precipitation.

Estimations of road salt use based on winter air temperature by the Finnish Meteorological Institute [119] found warmer than normal weather in November and March and colder than normal weather in December, January and February reduces the need for salting. Warm mid-winter months mean slippery conditions and, consequently, an abundant use of salt. The temperature explained about 60% of the annual variation of salt use and thus gave surprisingly good estimates for the required LOS. Air temperature is measured reliably at almost all meteorological stations and the use of air temperature for the estimation of road maintenance conditions is a tempting alternative compared with the use of more complicated indices calculated using meteorological observations available at only a small number of stations also referred to as the Road Weather Information System (RWIS).

RWIS is a system of sensors connected together to provide real time, accurate and site specific pavement surface conditions and weather data. Individual RWIS sites are sometimes referred to as remote processing units (RPU’s), consisting of several atmospheric sensors mounted to a tower, sensors embedded within and below the pavement surface, with all connected to a data processing unit and communications equipment. Initial research indicates Montreal currently uses RWIS technology, although it is not clear to what extent this data is applicable to Ville-Marie’s condition. Nonetheless, a study conducted in Northern Europe has demonstrated a correlation between air temperature and anti-icing application rates with a good degree of accuracy at predicting anti-icing measures on a day-to-day basis.

It is proposed that in the absence of RWIS data a test station be designed using off the shelf components for on-site monitoring that would approximate the high and low condition of an average Ville-Marie precipitation/storm event . Inclined and horizontal pavements with partial covers would be designed with sensors embedded in the pavement at critical locations. Before or during a precipitation event, data could be collected in order to calculate the level of service required.

ECOTOXICITY ESTIMATES

While numerous studies have been conducted regarding the effects of NaCl on a wide variety of species, more often, they are focused on crop producing plants. Consequently, little is known about the effects NaCl, MgCl, CaCl, or other additives on native species that once were in abundance along the St. Lawrence basin, but are currently on Environment Canada’s priority list as endangered and vital to the survival of the St. Lawrence basin.[118] The goal of this section would be to suggest a species of native plant most resilient to the proposed salt loadings as a remediation process for river embankments along the St. Lawrence in addition to provide ED50 (Effective Dose) and LD50 (Lethal Dose) estimates of the proposed alternatives on those plants. Following is a brief study plan outlining the stages of completion:

Select three plants from Environment Canada's priority list for the St. Lawrence.
Sow seedlings of these plants hydroponically in rock wool and varying concentrations of alternative chemicals to determine by visual inspection; a) the ED50 and LD50 of seedlings, b) test the hypothesis that seedlings sown in elevated concentrations of salts are later more resilient and grow faster under similar conditions.
Once the first leaf has emerged, transplant into a hybrid hydroponic system and continue to grow the plants which survived stage 1 in concentrations of different alternatives to determine by visual inspection; the ED50 and LD50 of the respective species. In addition, test the hypothesis that some levels of these components are beneficial to plant growth.

The study would take about 5 weeks to grow seedlings to first leaf and complete stage 1 using existing Concordia University greenhouse and hydroponic equipment left over from a previous PhD thesis. Stage 2 would be continued until for another 2 months or sufficient points are collected along the growth stage to determine the LD50 and ED50. Time permitting; the fruiting stage will be examined to determine if there are any adverse/beneficial effects of the alternatives by assay of root stocks and fruiting matter although evidence suggests there is no benefit.

In 1974, G.P. Lumis, Department of Horticulture Science, and G. Hofstra and R. Hall, Department of Environmental Biology, University of Guelph, published results of their research on Salt Damage to Roadside Plants which will serve as a guide towards characterizing symptoms specific to each species. The study will be conducted by experienced team member(s) in a controlled environment and in accordance with Good Laboratory Practices (GLP) and prepared protocols. Concordia lab personnel have been given the mandate to work towards our project goals and will perform most of the laboratory testing as required in accordance with test protocols (Appendix B). All aspects of the study will be monitored by CCTV and data will be recorded at regular intervals using a laptop and web-cam connected to the internet. In addition to visual inspection of the plant systems, regular measurements of leaf formation, stock lengths, bulk weights, and various other growth variables and disease characteristics will be recorded to determine the ED50 (Effective Dose) and LD50 (Lethal Dose) for particular species.

PILOT STUDY

Having accumulated sufficient background knowledge of the process, a pilot study involving trained Ville-Marie personnel and retrofitted equipment (See figure 8 - 10) would be conducted in accordance with prepared operating procedures using applicable anti-icing techniques to determine what measures specific to their needs should be addressed in the final proposal. Over a period of time, weather forecasts will be monitored; LOS will be calculated by team members and conveyed to management and maintenance crews who then will apply the LOS required. Team members will monitor each step of the process and perform LOS estimates after each application.

LIFE CYCLE ASSESSMENT

The goal of any good design is to support a continuing effort to improve and maintain environmental quality by reducing energy and materials consumption and by minimizing the impacts of pollution generated by the production, use and disposal of goods and services available to Canadians.

Based on a review of currently available life cycle information, mitigation of salt requirements will produce an environmental benefit through the reduction of harmful chlorinated air emissions and water effluents adverse effects on species. Therefore, the goal of this endeavor is to provide future policy makers with a more thorough life cycle analysis specific to Montreal’s condition and the alternative available.

Toward these endeavors, Life Cycle Assessment (LCA) is increasingly being used in waste sectors in Denmark which includes input of energy and resources as well as output of waste and emissions to air, water and soil. More importantly, acidification and ecotoxicity are examples of environmental impacts that are assessed in the LCA. [121] These and other research material will serve as guidance documents which form the basis for this assessment.

References

[100] Environment Canada, “CEPA Environmental Registry”, Canada Gazette Part I, Vol. 135 No. 48, Dec. 2001
[101] Terry, Robert C, “Road salt, drinking water, and safety; improving public policy and practice”, Cambridge, Mass., Ballinger Pub. Co. ,1974
[102] Federal-Provincial Subcommittee on Drinking Water (Canada) , Guidelines for Canadian drinking water quality / prepared by the Federal-Provincial Subcommittee on Drinking Water of the Federal-Provincial Advisory Committee on Environmental and Occupational Health, 6th ed , Ottawa : Health and Welfare Canada, 1996
[103] Environment Canada, “Risk Management Strategy for Road Salts”, 2006, http://www.ec.gc.ca/nopp/roadsalt/reports/en/rms.cfm
[104] Priority substances list assessment report : inorganic chloramines Publisher [Ottawa] : Environment Canada : Health Canada, c2001
[105] Delisle, C.E. and L. Dériger. 2000. “Caracterisation et élimination des neiges usées : impacts sur l’environnement”, Report submitted to the Environment Canada CEPA Priority Substances List Environmental Resource Group on Road Salts. Commercial Chemicals Evaluation Branch, Environment Canada, Hull, Quebec.
[106] Morin, D. and M. Perchanok. 2000. Road salt loadings in Canada. Supporting document for the road salts PSL assessment. Report submitted to the Environment Canada CEPA Priority Substances List Environmental Resource Group on Road Salts, May 2000. Commercial Chemicals Evaluation Branch,Environment Canada, Hull, Quebec. 85 pp.
[107] Ville de Montréal , “Measures to improve snow removal operations“, 2009, http://ville.montreal.qc.ca/portal/page?_pageid=5637,30739593&_dad=portal&_schema=PORTAL
[108] Wisconsin Transportation Center, “Wisconsin Transportation Bulletin No. 6: Using Salt and Sand for Winter Road Maintenance", 1996
[109] Pinard, D., J.B. Sérodes and P.A. Côté. 1989. “Charactérisation des eaux de fonte d’un dépot à neiges usées.” Sci. Tech. Eau 22(3): 211-215.
[110] Delisle, C.E. and A. Leduc. 1987. Évolution dans le temps et dans l’espace de la qualité de la neige usée et de l’eau de ruissellement de pluie du territoire de la Ville de Montréal. Centre de développement technologique de l’École Polytechnique de Montréal. Final report. 155 pp. + annexes.
[111] Péloquin, Y. 1993. Qualité des eaux de fonte provenant d’un site de surface pour l’élimination des neiges usées à la Ville de Laval. Université du Québec à Montréal, Montréal, Québec. 91 pp.
[112] Snodgrass, W.J. and D. Morin.,”Patrol (maintenance/works) yards. Supporting document for the road salts PSL assessment”, July 2000, Commercial Chemicals Evaluation Branch, Environment Canada, Hull, Quebec.
[113] Ville de Montréal , “Measures to improve snow removal operations“, 2009, http://ville.montreal.qc.ca/portal/page?_pageid=5637,30739593&_dad=portal&_schema=PORTAL
[114] Government of Canada,” Notice with respect to the Code of Practice for the Environmental Management of Road Salts”, 2009 http://www.gazette.gc.ca/archives/p1/2004/2004-04-03/html/notice-avis-eng.html#i1
[115] Gooding, D. and A.J. Bodnarchuk. 1994. Field trials of prewetting salt and sand with MgCl2 and CaCl2 brines: Efficiency and effects. Highway Environment Branch, British Columbia Ministry of Transportation and Highways. 7 pp.
[116] Environment Canada, Envirozine, “Protecting the Environment while Maintaining Road Safety in Winter”, Issue 49, Dec. 2004, 5 pp.
[117] Environment Canada, “Case Study # 6 - Winter Maintenance Innovations Reduce Accidents and Costs - City of Kamloops”, May, 2005, http://www.ec.gc.ca/nopp/roadsalt/cStudies/en/kamloops.cfm
[118] Environment Canada, “Biodiversity Portrait of the St. Lawrence – List of Priority Vascular Plants“, Dec. 2002, http://www.qc.ec.gc.ca/faune/biodiv/en/recherche/regions/recherche_regions.html
[119] Finnish Meteorological Institute ,“Estimation of road salt use based on winter air temperature”, Meteorological Applications, vol. 8, Issue 3, p.333-338
[120] Birgisdóttir, Harpa. Ph.D. Thesis, “Life cycle assessment model for road construction and use of residues from waste incineration”, Jul. 2005
[121] U.S. FWHA,” Manual of Practice for an Effective Anti-icing Program”, Nov. 1996.

The Risks of Lithium Technology (Part 2)

2009-10-20T10:09:00.012-04:00

In Part 1 we examined the history and engineering behind Lithium battery technology and drew comparisons between alternative technologies in use today. In part 2 we will explore the impacts of Lithium technology on society.

Economics at the Wheel

All too often, social hardship triggers technological innovation. So, it’s no wonder that despite the current global economic turn down, many remain optimistic of emerging lithium ion technology as a fitting surrogate to wean us from our oil dependency and usher in an era of sustainability. Since being introduced to the market in the early 1990s, production of lithium ion batteries has increased 4-5% per year resulting in a 6 billion dollar market as of 2008 [305]. At the same time, the conventional lead acid battery market, driven primarily by the automotive sector, is estimated to be a staggering 40 billion dollar industry by comparison, of which lithium is poised to replace.

Consequently, while the lithium battery sector has been growing just to keep pace with current demand of consumer electronics, the addition of emerging markets; satellite, aviation, military, UPS or stationary energy storage systems, has created a lithium supply shortage [306], even before the emerging automotive sector is accounted for and could actually cause the price of electric vehicles to climb despite a rise in demand, making it less affordable for the majority of users.

There are other shortfalls. Dr. Ralph Brodd points out in his briefing Advanced Automotive Battery Investment Summit, 17 June 2008 in Chicago [305], that the current lithium battery market is based on a global economy and while the trend has opened many opportunities, it also creates some problems as companies often move factories from high labor cost countries like Canada and the United States, and build them instead in Asia or Mexico. Such is the present case; the technology and manufacturing he argues are controlled oversees and bolstered by large investment, which the west has been unwilling to make. While manufacturers in the U.S. have managed to configure large lithium ion batteries for mass production and ensure they are long-lasting and safe, “the vehicles themselves are still too expensive for the average consumer without hefty government incentives and the troubled auto industry has yet to settle on which next-generation technologies (Li ion or Fuel Cell) will prevail in the market” according to the Times of India.[307]

Political Roadblocks

When considering the negative impact electric vehicles may have on the oil industry, a 46 billion dollar battery sector pales in comparison to the countless trillions oil producers stand to lose should lithium usurp its market. How this might impact future political trends is difficult to determine given the slickery and suasiveness from the oil industry in the past. By the same token, increasing political tensions stemming from the Middle East, South America, and Asia with the United States, coupled with rising global dependency on oil continue to be a recurring theme, once again with lithium playing the role of the underdog caught in the crossfire of political and economic agendas.

We’ve been here before. Let us not forget the oil crisis of 73 [308] spawned by political tensions in the Middle East which served as the precursor to the technological stagnation and demise of the electric car during the 80’s [309], due to the oil industry and bad politics as many suspect. Perhaps it is a sign of rational thinking that oil companies like Exxon [310] are researching and patenting integral lithium battery components. Given their track record, perhaps it’s a lesson we should be mournful of. Either way, it would serve society well to reign in the usual suspects before any crimes are perpetrated and countless resources fall by the waist side once again.

Towards these goals, new vehicle emission standards [311] like those recently implemented by Obama will likely be the impetuous of change needed for lithium battery stakeholders. Analyst David Begleiter, of Deutsche Bank North America is confident of the lithium batteries success saying, "There is no question the long-term trend is toward lithium-based batteries, but it depends on what kind of demand there is," and ads, "It is clear to me that regulatory moves on fuel efficiency are going to help make electric cars a reality."

Moreover, Obama’s recent $790 billion economic stimulus legislation [312] contains tens of billions of dollars in incentives for advanced battery research and manufacturing in addition to incentives for electric vehicle research, infrastructure improvements to the electrical grid, and funding for renewable energy systems, all which could help create a market for these batteries. Resources have already begun to trickle down to the state level. New York’s governor Paterson more recently announced the creation of the New York Battery and Energy Storage Technology Consortium (NY Best) [313] to position the state as a world leader of lithium battery manufacturing and other states like California, Maine, and Illinois are joining forces.

However, while new lithium technologies are being positioned in North America to dominate the market, geo-political tensions between Bolivia; where the bulk of global lithium deposits exist, and U.S. policy remain high. Although, Evo Morales, Bolivia's president wants lithium mining and refinement to be state run and plans to use that money for health, education and fight poverty in the country, according to April Howard of Toward Freedom [314], "The current political situation in the country is acting as a strong disincentive for western mining companies to operate there" says William Tahil, Research Director of Meridian International Research [315], and warns that lithium-rich South America would become the new Middle East. "Concentration of supply would create new geopolitical tensions, not reduce them."

Social and Environmental Risks

Despite advances; the new lithium battery technology is not prone to overheating, does not lose charging capacity as time goes by, can charge in seconds instead of hours, allows for the development of smaller and lighter products, there are associated social risks unaccounted for.

Production of this new battery does not stray far from the current process as MIT developer Gerbrand Ceder believes [315], and it would take only a few years to get the new lithium technology into the market. Yet social impacts on South America and Bolivia in particular are still being debated, and it may already be too late to change course given the economic engines of progress are fueled up for the race to Bolivia’s lithium. Moreover, South American governments have a history of corruption; leading to the probability that irreversible environmental damage to Bolivian land and communities due to the past 500 years of exploitive mining may continue unabated [316].

Furthermore, an alarming report from Meridian International Research confirms that “mass production of Lithium Carbonate will cause irreparable ecological damage to ecosystems” [317] and ads, “LiIon propulsion is incompatible with the notion of the Green Car". Vast areas of wilderness will have to be sacrificed to create settling ponds for the Lithium Carbonate mixture to vaporize. Other concerns include the effects of the refining structures and processes on people and animals. According to chemist Pedro Crespo Avizuri; “A key question is what to do with the mountains of magnesium we’ll make in the process” [316]. And this is just the tip of the iceberg as Lithium isn’t the only metal found in this new breed of batteries.

Lithium batteries also contain cobalt, copper, nickel, iron, and a brew of polymers which according to the federal government; do not pose any hazardous risks to the environment. Consequently, 2 billion lithium ion batteries are ending up in landfills and incinerators each year [318] despite Europe’s growing trend towards sustainability and the ever increasing demand for these materials.

Nonetheless, initiatives are underway in Canada and the U.S. to promote recycling. RBRC in Canada and the U.S. have been fundamental in establishing incentives for rechargeable power industry members to provide leadership and promote recycling, however, only 3 states in all of North America; California, Maine, and New York [319] have legislated mandatory recycling of cell phone and laptop batteries. As a renewable yet finite material, lithium batteries and its constituent metals will likely find a growing market in capture and recovery sectors as future demands continue to out weight supplies.

A New Course of Action

While the future of lithium technology holds all the makings for a good detective story, there are clues that point to a possible ending. Lithium battery technology is already in transition to take over the consumer electronics market and the lion’s share of the lead acid sector. As a consequence, a lithium supply shortage is already occurring and analysts predict less affordable vehicles for the majority of buyers down the road should lithium ion supplant oil. Nonetheless, emission control standards, financial incentives, and public awareness are helping to push lithium technology and make electric cars a reality in the U.S. and abroad. Less evident, however, is the irreversible environmental damage to Bolivian land and communities or the notion that lithium is fundamentally incompatible with green technology.

Whether we choose to follow the breadcrumbs history provides or investigate new leads; the politician, the banker, and that old antagonist - risk, might not always be central characters in a techno-thriller like this, but one fact remains that we should not lose sight of. The motive for any great detective story; someone always dies in the beginning.

Society’s best intentions are often misguided and it isn’t until some catastrophic event that meaningful progress is deemed necessary. The proof is in the words of the world’s greatest detective, Albert Einstein, who said, "The splitting of the atom has changed everything save man's mode of thinking, thus we drift toward unparalleled catastrophe”. [320] Let us hope that society can make better use of this technology and change its way of acting, if not it’s way of thinking before it is too late.

References

[301] Disclose. “Ancient Baghdad Battery ( IRAQ )” Nov. 2008: http://www.disclose.tv/action/viewvideo/12521/Ancient_Baghdad_Battery___IRAQ__/
[302] Hugh Chisholm, ed (1911). "Parthia". Encyclopaedia Britannica. 20. London: Cambridge University Press. pp. 871. http://encyclopedia.jrank.org/PAI_PAS/PARTHIA.html.
[303] The Leyden Jar Discovered — World Wide School
[304] Lewis F. Urry at Find A Grave
[305] Vidler. ”Advanced “Automotive Battery Brief” June 2008: http://www.viddler.com/explore/evworldeditor/videos/1/
[306] EVWorld, “The Trouble with Lithium” Dec. 2006: http://www.evworld.com/library/lithium_shortage.pdf
[307] The Times of India. “US firm unveils new battery technology for electric cars“ May 2009: http://timesofindia.indiatimes.com/Health--Science/Science/US-firm-unveils-new-battery-technology-for-electric-cars/articleshow/4527860.cms
[308] http://www.state.gov/r/pa/ho/time/dr/96057.htm Second Arab Oil Embargo, 1973-1974
[309] Google video. “Who Killed the electric Car” Feb. 2007: http://video.google.com/videoplay?docid=-6437080948273722203
[310]Futurepundit. “New Exxon Mobil Film For Lithium Ion Car Batteries” Nov. 2007: http://www.futurepundit.com/archives/004825.html
[311] The Guardian. “The lithium boom is coming: The new bubble?” May 2009: http://www.guardian.co.uk/business/feedarticle/8521396
[312]Technology Review. ” Stimulus Big Winner: Battery Manufacturing” Feb. 2009: http://www.technologyreview.com/energy/22188/
[313] New York State Governors Office. “GOVERNOR PATERSON ANNOUNCES CREATION OF THE NEW YORK BATTERY AND ENERGY STORAGE TECHNOLOGY CONSORTIUM (NY BEST)” May 2009: http://www.state.ny.us/governor/press/press_0505094.html
[314] Toward Freedom. “The Battle Over Bolivia’s Lithium and the Future of Energy“ May 2009: http://towardfreedom.com/home/content/view/1582/1/
[315] PCMag. “Quck-Charging Li-Ion Batteries Could Appear Soon” Dec. 2009: http://www.pcmag.com/article2/0,2817,2342919,00.asp
[316] In These Times. “Salt of the Earth” May 2009: http://inthesetimes.com/article/4360/salt_of_the_earth
[317] Meridian International Research. “The Trouble with Lithium 2” May 2008: http://www.meridian-int-res.com/Projects/Lithium_Microscope.pdf
[318] St. Cloude State. “Lithium Mining and Processing” http://studentweb.stcloudstate.edu/lipa0401/Lithium..pdf
[319] RBRC. “Recycling Laws” http://www.rbrc.org/community/recycling_laws.shtml
[320] CyberWorld “FamousQuotes” http://www.garrydavis.org/p_quotes.html

Water Pollution and Control

2009-10-20T06:29:00.015-04:00

While care must be taken to ensure sewage, storm water and agricultural runoff are controlled in a manner safe to public heath, recreational waters may become readily contaminated by anthropogenic factors. In fact; “many epidemiological studies have identified gastrointestinal and upper respiratory illnesses in bathers that were a result of such contamination.” [1]

Whence, the ideal indicator of fecal contamination of recreational waters would be one of the enteric pathogens, such as Salmonella or Norwalk virus, however, because these are usually present at low levels and are irregularly distributed, even during disease outbreaks, they are difficult to isolate and quantify. [1] Moreover, the absence of one enteric pathogen does not necessarily preclude the absence of another. Testing for every possible waterborne disease-causing microorganism would not be pragmatic and it is therefore common practice to monitor more plentiful but non-pathogenic surrogate bacteria present in human and animal feces.

The indicator organism most widely used is the bacterium Escherichia coli (E. coli); sometimes referred to as fecal coli forms, which are present at about 10^7 bacteria per gram of dry feces. A simple, accurate, nonlethal membrane filter technique [2] for the rapid enumeration of E. coli from marine, estuarine and fresh water samples was used to determine the presence of possible pathogens in a natural stream within 24 hours without requiring subculture and identification of isolates. m TEC Agar was used for isolating, differentiating and rapidly enumerating thermo-tolerant Escherichia coli from water by membrane filtration.

Results after 24 hr of incubation showed zero E. coli cfu (colony forming unit) as expected given the tendency for natural river systems (where the sample was taken) to self-purify. A sample collected from a source expected to have possible coli forms was also tested and showed the presence of E. coli in addition to other coli forming units.

Introduction

Currently the membrane filtration (MF) technique for enumerating fecal coli forms in water is the most widely used. Counts are expressed as colony forming units or CFU. Since coli form density may be high, in for instance raw sewage, sample dilution will be necessary to get optimum plate counts of about 20 to 80 CFU per plate. Usually about 10 to 100 ml are filtered in triplicate for each dilution level. In this experiment, natural water is used, and results are expected to show <200 CFU/100ml. A 500ml undiluted sample will be used.

Method and Procedure

Wearing protective clothing and working in a biological hood, method and procedures are prepared in accordance with FDA Method 1603. [2] A well-mixed water sample of known volume is passed through a sterile 0.45 urn pore size membrane filter, under vacuum. After filtration the membrane retains all the bacteria on its surface. The membrane is placed on a nutrient-media and incubated for 24 hours; which promotes the growth of E. coli. Each bacterium can give rise to a visible, characteristically stained, colony for counting.

Results and Discussion

As would be expected, samples collected along a natural stream showed zero E. coli and eight other colony forming units as reported by the lab technician after 24 hours of incubation. In Figure 1 (right), 6 small and 1 large E. coli (fucia) and several other counts (yellow and pink) are observed on samples collected from a dog’s water dish [3] and incubated for 48 hours.

Despite having aeration, circulation, and filtration using activated carbon, water samples collected from the dish after 4 days of continuous operation show evidence of possible pathogenic growth. Further identification by experienced practitioners to generate genetically pure cultures from a mixed culture of genetically different organisms, using a technique known as streaking [4] would be required to adequately determine their nature and risk. Upon further discussion, the lab technician pointed out experience has shown natural flora and bacteria would be present in the dog’s mouth and the presence of E. coli doesn’t preclude the counts from being non-lethal. As such, this information does provide a reliable measure concerning the effectiveness of the practices employed on the dog’s dish. Furthermore, the results show that chlorine is no longer persistent in the tap water used in this study after 4 days and that aeration in addition to other factors may be reducing chlorine.

The MF technique described above does provide a quick and elegant indicator for the presence of enteric pathogens in water. Early detection is paramount. Figure 2 (left) shows molds growing on the natural water sample after 7 days!

Although the MF test is relatively simple, there are many assumptions and potential errors behind extrapolating the mean coli form density from a water sample to a water body such as temporal and spatial coli form distribution variation, potential die-off after sampling due to chlorine damage, or subsequent re-growth in the water body, believed to be due to cellular recovery after chlorine damage. Also, since a colony may derive from one coli form, or a clump of more than one bacterium, the actual bacterial count may be greater. Nonetheless, this simple test, when performed properly in conjunction with a sound sampling regime, can protect large populations of humans from the disastrous consequences of water contamination.

References

[1] Health Canada, Guidelines for Canadian Recreational Water Quality, May 8, 2009 http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/guide_water-1992-guide_eau/section3-eng.php
[2] Method 1603: Escherichia coli (E.coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC), September 2002, http://www.epa.gov/nerlcwww/1603sp02.pdf
[3] Rush, D. , Help your pets make better choices, Jul. 2009, http://eco-eng.blogspot.com/2009/07/update-help-your-pets-make-better.html
[4] Wikipedia, Streaking (Microbiology), May 2009, http://en.wikipedia.org/wiki/Streaking_%28microbiology%29

Vermicomposting - Week 6

2009-10-07T21:11:00.016-04:00

While vermicomposting is going well with managing about half the kitchen scraps our household generates, more can be done to aid the worms in reproduction. Several weeks into composting, I was still unable to find any cocoons despite hours of searching under red light.

Further research indicated the colony (250g) might be too small for the size of bin (76L). In order to remedy the situation and promote reproduction, a new bin (20L) has was constructed using a scale down model of the original. Feeding was resumed as per the regular schedule and with continued monitoring of pH, moisture, and temperature as well as regular observations under the cover of red light.

The system consists initially of two bins with a bottom bin for catching castings, leachate, and to provide support space for bottom aeration of the reactor bin. The bottom of the middle reactor bin was cut away and replaced with screen with about a 2mm mesh

opening. A second vessel with 80mm mesh bottom is placed on top and filled with fresh bedding. Feed stock is initially introduced into the middle bin, where casting and leachate pass through the screen and are captured in the bottom bin. Worms are free to migrate into the upper vessels through the 80mm screen opening once the bottom vessel has been completely exhausted. A new bin is added to the top and the process is continued in top bin with fresh bedding and feedstock added incrementally.

After reducing the volume of the worm bin considerably as well as reducing moisture levels, the worms have begun to lay cocoons.

Determining Energy Losses in Pipe Flow

2009-09-26T11:41:00.031-04:00

This lab was prepared by Dr. S. Li for students taking CIVI 484 Hydraulic Engineering in Fall, 2009 at Concordia University.

This experiment is about energy head losses in pipe flow. Energy head losses always occur in pipe flow due to skin friction on the pipe wall. Additional energy head losses occur due to disturbances to pipe flow streamlines triggered by valves and such pipe fittings as bends, sudden expansions and contractions.

Energy Equation Between cross section 1 at upstream and cross section 2 at downstream along a pipe (the figure below), we may write the energy equation

where P is pressure, λ is the specific weight of water, z is elevation, V is flow velocity, g is the gravitational acceleration, and hL is the energy head loss that has occurred between the two cross sections. The subscripts 1 and 2 refer to cross section 1 and cross section 2, respectively.

Energy Loss in a Straight Pipe

Consider pipe flow through a straight section of a pipe free from fittings. The energy loss caused by skin friction on the pipe wall can be expressed as

where f is the Darcy friction factor, L is the length over which the loss has occurred, and D is the diameter of the pipe. The Darcy friction factor can be determined experimentally. However, in most cases, it is directly obtained from the Moody diagram. The Moody diagram shows two limiting cases: f for laminar flow,f for turbulent flow. Under these conditions, f can be derived theoretically or determined using an empirical correlation.

Energy Loss in Fittings

In addition to the energy loss caused by skin friction, energy losses result from pipe fittings. This is because the pipe fittings disturb flow velocity streamlines. We relate the additional energy loss due to a pipe fitting, hloss, to the local velocity head, through a loss coefficient, K

From measurements of the additional energy loss and the flow velocity, we can determine the coefficient.

Procedure

Students use a closed pipe flow system called Flow Bench F1-21, manufactured by Armfield Engineering Education. The main components of the system are:

• a pump
• closed pipe sections
• a steelyard
• a manometer board connected to ten pressure taps
• a valve for flow rate control
• pressure taps at ten locations along the pipe
• a hand pump

(1) Place the bench on a level platform.
(2) Check the gate valves to ensure the inlet and outlet valves of the pump are open.
(3) Start the pump.
(4) Set the flow rate by adjusting the valve for flow rate control.
(5) Record the values for the pressure head at ten locations along the pipe flow. These
values are indicated on the manometer board. Use the hand pump for
pressurization of manometers.
(6) Record the total discharge by weight over the period of each experiment run.
(7) Record the run time of the experiment.
(8) Record the diameter of the pipe sections along the path of the flow.

Calculations
(1) From standard textbooks or hydraulic field manuals, find the roughness height of the pipe material ε . Determine the relative roughness, ε / D, where D is the diameter of a pipe section.
(2) Find the friction factor f in equation (2).
(3) Find coefficient CHW in the Hazen-Williams equation. The equation is of the form

where Rh is the hydraulic radius, and S is the slope.

Raw data and diagrams:

You can download the raw data in Excel format here.

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Results
TBD after the lab has been submitted. Meanwhile, here are some more photos of Group 1 in action.

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Vermicomposting - Week 3

2009-09-23T20:48:00.002-04:00

With a little luck, the worms have survived 3 weeks in their new surroundings and were doing a great job at managing about half their weight in organic waste from our kitchen which was otherwise destined for the landfill. They appear to be gaining weight and a layer of casting has begun to form along the bottom of the bin. Moisture levels are much higher now with casting forming and leaching taking place from aging feed stocks. Most likely caused by over zealous feeding, an ammonia odor was detected a few days ago. The bedding was turned and fresh cardboard was added while feeding was suspended for two days, which seemed to alleviate the anaerobic condition caused by overfeeding. The remedy the situation, a small scale is now used to record the quantities of food stock until a regular feeding schedule can be established.

The Risks of Lithium-Ion Technology (Part 1)

2009-09-19T10:39:00.027-04:00

No one can argue the impact battery technology has had on society; ushering in an era or portability and mobility like never before, all the while helping to spark a green revolution, and empower people with tools and ideas for a sustainable future. What’s more, emerging lithium ion technology provides significantly faster charge, longer life, and designers in the U.S. have managed to configure large lithium ion batteries for mass production and ensure they are long-lasting and safe for the auto industry.

Risks seemingly mitigated, recent incentives and regulation will surely mean a boon for lithium technology, however, social, environmental, and political debates rage on between the Middle East, South America and the United States over control of lithium and oil resources. Furthermore, a growing global dependency on oil, coupled with the countless trillions oil producers stand to lose should lithium ion replace oil only serve to create new geopolitical tensions and promote false claims, rather than help abate existing ones.

In the course of two articles, we will discuss these issues as they pertain to emerging Lithium-Ion technologies, examine the history and engineering behind such inventions, and draw comparisons between alternative battery technologies in use today. These papers will explore the functionality of lithium batteries and investigate the pros and cons of different technologies as they relate, and aim to shed light on the associated social and environmental risks.

A Brief History of the Battery

As we have witnessed since the dawn of the industrial revolution, the complexity and pace at which technology transform society are relentless. Following the trail of events from some point in the past to a piece of modern technology is somewhat like a detective story; full of sudden twists and turns, deception, and guess work! You’ll never know where the story is heading until the last minute. Why those inventions happened is a blunderous blend of accident, genius, war, economics, religion, politics and countless other social factors involved in the business of change. The invention of the battery is no exception.

Our story of the battery begins with the three ceramic pots uncovered during archeological excavations near Baghdad [301]. Around this time Mesopotamia (modern Iraq) was occupied by the Parthians, a nomadic tribe of skilled warriors, who had literature and kept records.[302] Yet the importance of such an unusual electrical phenomenon seems to have gone completely unrecorded within the Parthian and contemporary cultures and then to have been entirely forgotten about for almost 2000 years. Is the Baghdad battery the accidental forerunner of electricity or did the Parthians, having knowledge of electricity, invent the battery? Perhaps more conspicuously, how did this incredible piece of technology go unnoticed for 2000 years? These mysteries may never be solved, but serve as a fitting prelude to our chronicle, adding accident, genius, and perhaps deception (in the form of alien theories and misguided propaganda) to the cast.

It wasn’t until 1745 that electricity was again stored in bottles, called Leyden Jars [303]; essentially a large capacitor jar filled with water, with metal foil around the outside and a nail piercing the stopper and dipping into the water. Born from necessity, Leyden jars and electrostatic generators were the scientist’s only source of electrical energy at the time and remained curiosities for amusement until Canadian Lew Urry patented the first modern alkaline battery in 1959[304], which served as the precursor to mass production by Ever Ready and Duracell starting in 1968.

Since then, developers have been focused on meeting the demands of the ever increasing consumer electronics market, which has resulted in faster, smaller, more powerful, and better quality batteries that also promise to meet the demands of the green revolution and electric vehicles in particular. In fact, the push towards renewable energy has thrust battery technology into the spotlight like never before and has resulted in a new breed of Lithium polymer batteries poised to empower a sustainable society.

250 BC	Baghdad battery
1800	Alessandro Volta invents the first modern electric battery
1901	Edison invents Nickel Iron battery
1960	Neumann develops Nickel Cadmium battery
1970	Union Carbide develops Lead Acid battery
1991	Sony commercialization of Lithium-Ion battery
1996	John B. Goodenough patented Lithium Iron Phosphate LiFePO₄ battery
1999	Sony commercialization of Lithium Polymer battery
2009	G.Ceder & B.Kang invents “Beltway Battery” based on LiFePO₄ technology

First generation Lithium cells first appeared in the late 1980’s, however, failed to attract consumer attention due to the inherent instability of Lithium metal during charging and research shifted towards a non-metallic Lithium battery using Lithium ions which were commercialized by Sony in the early 1990s. While Lithium-ion batteries proved to be safer, they were still prone to “thermal runaways” if mishandled and had lower energy density than Lithium metal.

A non-volatile Lithium Iron Phosphate battery was developed for medical uses in 1996, but, low energy density kept it from widespread use until 2003 when the charge efficiency of Lithium Iron Phosphate batteries had improved enough to allow use in military and medical applications such as the pacemaker.

How Lithium Technology Works

A lithium-ion battery consists of a cathode layer, an anode layer, and a separator between them. When the battery is charging (figure 1), positively charged lithium ions move through a liquid electrolyte from the cathode to the anode and in the opposite direction when the battery is discharging (figure 2). The electrolyte is a lithium salt, dissolved in organic solvents. [103] Lithium batteries come in two types, primary lithium batteries (single use batteries) and secondary batteries (rechargeable batteries).


Figure 1 – Charge Cycle	Figure 2 –Discharge Cycle

[106]:The rechargeable Lithium batteries are broken into three group types, based on the recharge rates

Slow: 14-16 hours
Quick: 3-6 hours
Fast: Less than 1 hour

The rate of charge is determined by how much electrical current is allowed into the battery by the charger and how fast it can force electron to flow from anode to cathode. Some batteries can handle a higher voltage in a shorter amount of time without overheating, while others need a lesser voltage applied over a longer period of time. The quicker the rate of charge, the more chance there is of overcharging. When the batteries are overcharged, the cathodes tend to release oxygen gas. The combination of oxygen, a flammable solvent, and heat can lead to a thermal runaway or cause the battery cell to explode. Faster secondary batteries use protection circuitry to balance or control electron flow to individual cells in the pack when charging. The circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge. Also, chargers have built-in voltage regulators that allow cell phones, computers, and other portable device to be left plugged in for extended periods of time. In addition, in fast charge batteries the cell temperature has to be monitored to prevent temperature extremes. The maximum charge and discharge current on most packs are is limited to between 1C and 2C. (C stands for capacity)

Types of Lithium Batteries

Despite all the drawbacks, the lithium based batteries have twice the energy density of standard nickel-cadmium batteries, typically AA, AAA, or any letter based batteries. The charge characteristics are reasonably good and behave similarly to nickel-cadmium in terms of discharge. For example, a Lithium-Ion battery has a maximum individual cell voltage of 3.6volts. Most of today's mobile phones run on a Lithium-Ion single cell. A nickel-based pack would require three 1.2-volt cells connected in series.

Lithium batteries are low maintenance batteries, an advantage that most other chemistries batteries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life. In addition, the self-discharge is less than half compared to nickel-cadmium. [106]There are several different categories of lithium batteries. Based on the type of electrolyte employed batteries can be used in verity of applications. Smaller size Lithium-Polymer batteries are used in portable devices and RC toys, Lithium-Ion have higher energy density but more riskier are used in stationary applications as backup electrical power or factory motors. Lithium Iron Phosphate batteries are used primary in medical applications and military where safety is at most importance.

Lithium type batteries are flexible in design and can be manufactured in any cylindrical or prismatic forms. The flexibility allows batteries to be used in wide variety of portable devices, power tools, and ultra slim appliances.

Shown in figure 3 (left) is a cutaway view of a lithium-Ion battery. Both the positive and negative feed-through (negative and positive ends) are located on the top of the battery and become as flat plates on the inside. Additional vents can be added to help relieve oxygen build up, sensors for monitoring temperature and reinforced casing (edge insulator) to prevent explosion of a battery if overcharged. [107]

Lithium Ion Batteries (Li-Ion)

Rechargeable Lithium Ion (Li-Ion) cells have a negative electrode (anode) made from lithium compounds. Lithium is a highly reactive material and is much lighter than the hydrogen-absorbing metal alloy of the Nickel-metal hydride battery (NiMH) negative electrode. This leads to higher gravimetric energy densities for the Li-Ion cell. [109]

Advantages	Disadvantages
Very high volumetric density Very high Energy density Can be stored +12 month without losing charge Expected life cycle of 500+	High cost of Lithium and cobalt metals Costly charge and discharge control Can cause health risks when explode

Lithium Polymer (Li-Po)

Lithium Polymer Ion batteries provide the performance of the Li-ion in a thin or moldable package. They do not use a volatile liquid electrolyte and can sustain significant abuse without explosion or fire. The lithium polymer uses a polymer gel electrolyte to replace the traditional liquid electrolyte. Lithium-polymer finds its market niche in wafer-thin geometries, such as batteries for credit cards and other such applications. [110]

Advantages	Disadvantages
Very thin profile Flexible form factor Light weight Improved Safety	Expensive Mo standard size Health risk of explosion High cost to energy ratio

Lithium Iron Phosphate (LiFePO4)

Lithium Iron Phosphate batteries (LiFePO4) were developed in 1996 by Dr. John B. Goodenough and his research team at University of Texas. His invention was patented and manufacturing permission was given to Phostech Lithium Inc. and Hydro Quebec. [111]

This type of battery is based on the existing Lithium Ion chemistry however, rather than using lithium cobalt oxide (LiCoO2) as a cathode, LiFePO4 uses Iron (Fe). Unlike cobalt, iron is non-volatile and does not produce oxygen. This means that even under severe operating conditions such as overcharging, deep discharging, or fast charging (which usually causes thermal runaway), LiFePO4 batteries will not burn or catch on fire. Because of this property, this type of battery can be installed in confined places or ones without ventilation. Furthermore, due to their slim cylindrical nature, custom batteries of virtually any shape can be made that will fit into tight space.

Another great advantage of LiFePO4 batteries is their extremely long life. If a battery left sitting on the shelf without use, it can last up to 20 years. Also LiFePO4 battery can typically be charged in excess of 2000 times and there are LiFePO4 cells which are currently under test at the US Department of Energy Laboratories in New Mexico which have recently passed 7000 cycles and are still working. [112]

Another advantage of these batteries is their rapid charge capability. LiFePO4 batteries can be re-charged extremely quickly. This rapid charge capability comes by necessity since these batteries have been developed for use in the electric cars in the near future. High end LiFePO4 batteries can be charged at 30C rate. This safety combined with their light weight has found wide use for these batteries for military and medical applications and now for the emerging electric vehicle market. However one trade off to safety is LiFePO4 does not have as high energy density as Lithium-Ion or Lithium-Polymer battery.

An overview of the benefits of Lithium Iron Phosphate batteries:

Advantages	Disadvantages
Longer cycle life (battery life) Discharge/charge current rates Higher resistance to Thermal Runaway Connected in series or parallel Uses not toxic metal and 99% recyclable Use of Iron and Phosphate rather than cobalt Higher power Density Solid Construction	Relatively new technology Lower individual cell voltage Energy densities are also lower

LiFePO4 batteries have only been commercially available on the market since 2008, first manufactured by A123Systems [113] for electrical bicycles and smaller electrical cars. As batteries became more popular, today more than a dozen battery companies produce them. Fist laptop size battery was used in XO children laptop in November of 2007, and cell phone size batteries were expected to be available in later 2010. [114]

Next Generation Lithium Battery

State of the art rechargeable LiFePO4, although having high energy densities, still have relatively slow power rates. Even at 30C discharge rates compared to Lithium-Ion batteries, improvement can still be made. A recent publication in March 2009 Nature magazine by Byoungwoo Kang and Gerbrand Ceder of Massachusetts Institute of Technology (MIT) claims a breakthrough with a small prototype battery made on existent LiFePO4 technology that can be charged fully in 10 to 20 seconds, compared to 6 minutes for the cell made in the standard way. [116]

The idea for the research came when Ceder questioned why electrical vehicles using Lithium batteries can drive continuously at 55mph but have very low power rates – how fast the car can accelerate. [117]

Traditionally scientists have thought that lithium ions responsible, along with electrons, for carrying charge across the battery simply move too slowly through the material. About five years ago Ceder a graduate student in material science and engineering made a surprising discovery. Computer calculations of lithium ions transfer in LiFePO4 showed that ions should move extremely quickly. “If transport of the lithium ions was so fast, something else had to be the problem” Ceder said. [118]

A deeper looking into calculations revealed that lithium ions can move very quickly into the material but only through tunnels accessed from surface. “If lithium ion is at surface directly in front of the tunnel entrance, there is no problem: it processes efficiently into the tunnel, however if the ion is not directly in front, it is prevented from reaching the tunnel entrance because it cannot move to access the entrance.” [118]

A way around it was modifying Lithium Phosphate material in electrode to allow ions and electrons move in and out much quickly. By including extra Lithium and Phosphorus helped created a layer of Lithium Diphosphate (Li4O7P2) on the surface. Only 5nm wide, Lithium Diphosphate has high lithium-ion conductivity, and ions and electrons that come in contact with it quickly shuttled to faces that can pull them in, allowing for very fast tunnel access.


Figure 4 “An amorphous layer (light-colored band at the right) on a crystalline battery material improves its performance.” [19]	Figure 5 “An electron micrograph of lithium nickel manganese oxide. The white layers are composed of nickel manganese oxide, and the dark layers represent lithium.” [20]

The technology has been nicknamed the “beltway battery”, after the orbital motorway in Washington DC, because it uses a bypass system to let lithium ions that carry charge to enter and leave the battery more quickly. [121] Figures 6 and 7.


Figure 6 Lithium Ion flow in a traditional battery [121]	Figure 7 Ion flow in the Beltway Battery [121]

To better illustrate the capabilities of the LiFePO4 batteries with Lithium Di-phosphate coating the fallowing example might be helpful. A high end laptop Lithium Polymer battery has fallowing specifications; Capacity of 2100mAh at 11.1V thus it can provide 23Watts-Hour of Power. Also it has a 20C continues discharge rate, and 1C charge rating. Capacity denoted as C and signifies a charge or discharge rate equal to the capacity of a battery divided by 1 hour. For example 1C for a 2100 mAh battery would be 2100 mA or 2.1 Amps for one hour, if discharges at twice the capacity (2C) the battery will give more current (4.2Amps) but will last less (30 minutes compared to original 60) The durations are summarized in the table below.

Li-Polymer	Current	Duration
1 C charge/discharge	2.1 Amps	1 hour
2C discharge	4.2 Amps	20 min
20C discharge	42 Amps	3 min

As mentioned, the problem with standard Lithium-Polymer batteries are low discharge and even lower charge rates. However LiFePO4 batteries with Lithium Di-phosphate coating can have a charge and discharge rate of 100 times its capacity. The same Lithium Polymer battery from above, can be charged or discharged at 100C, thus it can charged at staggering 210 Amps in only 36 seconds. By comparison, 210 Amps at 11.1V equals to 2.3kWatts of power. This is equivalent to 23 100Volt light bulbs turned on for 36 seconds.

The Impacts of Society on Battery Technology

In Part 2 of this series we will explore the impacts of society on battery technology and look at how emerging Lithium Iron Phosphate technology will change how we use battery powered devices.

Secondary Treatment for Montreal Water

2009-09-18T21:49:00.001-04:00

Montreal’s wastewater treatment plant, located in Pointe-Aux-Trembles, is the largest in North America and ranks the third largest in the world. Yet despite it’s an extraordinary capacity of 32 m3/s, the treatment process itself is actually one of the worst in Canada. In fact, a national “report card” issued by the Sierra Club in 2004 gave the city’s treatment process a grade of F-.

The biggest problem is that Montreal only provides primary treatment of its sewage in comparison to most other cities across Canada delivering secondary and even tertiary treatment of wastewater. As a result, the plant’s effluent remains full of pharmaceuticals, in addition to heavy metals, and a multitude of other contaminants.

While this pollution is usually kept clear from the shores of Montreal, it has begun to migrate downstream of the island where effluent was recently shown to be "seriously inadequate" when it comes to removing harmful pharmaceutical drugs from the river’s ecosystem.

In keeping pace with these findings, a variety of biological treatment methods have been developed to treat such persistent pollutants and research continues to provide new and innovative ways of treatment right here in Quebec. Montreal would greatly benefit from a secondary and even tertiary biological treatment process.

As such, the aim of this project would be to explore viable biological treatment processes for the Montreal treatment facility and put forth design alternatives for consideration. It would involve visiting the facility on a regular basis to work with the engineers, collect samples, analyze lab results, and report findings that point towards viable solutions. The project could be expanded to include design alternatives for the facility that would aid future builders (perhaps us) in their endeavors.

UPDATE (09/22/09): The city of Montreal already has plans to install an Ozonation process once the money is raised and we've hit a dead end with this project.

Vermicomposting - Week 1

2009-09-09T19:37:00.004-04:00

After visiting the Concordia University greenhouse and seeing their vermicomposting system in operation I was inspired to give it a try as a means of achieving our goal of a zero garbage home. One of the major obstacles day-to-day green practitioners in northern climates face is a short composting season which precludes using outdoor composting during late fall to early spring. Vermicomposting solves this problem.

Following the various guidelines and advice online, a vermicomposting bin (batch reactor) was constructed from two 76L Rubbermaid totes with 3mm holes for aeration along the sides and lid and 2.5cm holes covered with 2mm screen for drainage along the bottom.

About 250g of kitchen scraps (carrots, cellery, potatoe, coffee grains and eggshells) was placed into 20cm of bedding consisting of shredded newspaper and cardboard (wet to the consistency of a wrung out sponge) a few weeks earlier in order to establish a microbial colony and ready supply of food for the worms' inoculation.

Two hundred and fifty grams of worms was introducted into the bin and some worms immediately began migrating out of their bedding. The lid was left off for a few days to allow the worms additional acclamation time, which seemed to solve the problem.

In addition to daily pH, moisture and temperature measurements, worms were periodically observed under red LED light. Initially, worms were observed to be docile and clustered around food stocks. Average temperature was 20ºC, moisture was kept around 80% with occasional spraying, yet pH quickly drifted below 7 despite lowering the amounts and varying types of feed stock.

Green Building Guidelines and Initiatives - A Canadian Perspective

2009-08-29T13:55:00.039-04:00

Gone are the days used up in favour of a disposable society, leaving the remains to provide for an explosion of civilization and that which they covet. Other complex cultures have perished throughout time from degradation to ecosystems and an inability to engineer a peaceful coexistence. So it is no wonder that today’s green/sustainable building practices have developed beyond concept into doctrine, finding their way into our hearts and politics. And while concerns about environmental degradation, resource shortages, and human health impacts are promoting widespread acceptance of green building practices, more can be done to aid the day-to-day practitioners in mitigating the enormous pressures on planetary ecosystems caused by human activities.

Towards these endeavours, the concept of resource conscious design, which ultimately aims to minimize natural resource consumption and impact on ecological systems, is presented in a familiar context. In particular, Canadian guidelines and initiatives are put forth as examples of current green building applications and their environmental benefits.

The Impact of Buildings on the Environment

Substantial energy and material resources are expended on the construction and maintenance of conventional buildings. As of 2006, buildings consumed 40% of the total energy consumed in both the US and European Union. (Wikipedia) As shown in table 1, buildings use 70% of the total electricity consumed, 12% of the total amount of potable water consumption per day, and 40% of raw material usage. Furthermore, 39% of the total carbon dioxide and 30% of waste output can be attributed to buildings. (USGBC) Moreover, buildings often result in environmental degradation such as loss of amenity and biodiversity which are much more difficult to assess. (Kibert 38) The major environmental impacts to be addresses by green building methods are covered in more detail in the following sections.

Climate Change

As a major energy consumer, an increasing reliance on fossil fuels, particularly coal - the dirtiest of all - includes the built environment as a key proponent to climate change. Furthermore, building materials and operations continue to be linked to ozone depletion, despite the United Nations Montreal Protocol of 1987 to halt production of ozone-depleting chemicals and restore the ozone layer by 2050. (Kibert 39) Even more disturbing, rampant deforestation degrades the capability of forests to sequester the large quantities of carbon dioxide stored in tree mass; instead, releasing it into the atmosphere as gaseous compounds, which further accelerate climate change.

Deforestation Desertification and Soil Erosion

With 2 acres of rainforest disappearing every second, only half the Earth’s forest cover still remains and because trees and their root systems prevent soil erosion, landslides, and avalanches, their removal contributes to soil loss (desertification) and changes the rate at which water enters the watershed. (Kibert 39) Moreover, large scale deforestation affects the albedo, or reflectivity, of the Earth, ultimately causing climate change and altering rainfall patterns and quantity worldwide.

Eutrophication and Acidification

Two environmental conditions that are a toxic threat to water supplies are eutrophication and acidification. Eutrophication refers to saturation of water bodies with agricultural and landscape fertilizer, urban runoff, and sewage discharge. An oversupply of toxins in the water fosters algae growth, which in turn block sunlight and cause underwater vegetation to die. Moreover, the algae consumes oxygen, further depleting the water body until eventually, the algae itself decomposes in a completely oxygenless lake or seabed, releasing toxic hydrogen sulphide, poisoning organism and resulting in total degradation of the aquatic system. (Kibert 41) Acidification refers to the process whereby air pollution in the form of ammonia, sulphur dioxide, and nitrogen oxides, mainly released by burning fossil fuels, is converted into acids resulting in acid rain which is damaging forests, lakes, soil, and even ancient historical monuments.

Loss of Biodiversity

Biologists are predicting the loss of 20 percent of existing species over the next twenty years due to deforestation and climate change. Destruction of ecosystems contributes to the spread of infectious diseases and species extinction prevents discovery of potentially useful medicines. (Kibert 42) Furthermore, ecosystems foster water and soil resources; nutrient storage and cycling; pollution breakdown and absorption; provide food and materials; in addition to many other undiscovered applications.

Depletion of Metal Stocks

Like oil depletion, a similar scenario is playing out with other key resources, most notably metals. A recent study of the supply and usage of copper, zinc, and other metals has concluded that supplies of these resources may fail to meet the needs of the global demands, even if recycled. Furthermore, because the rate of use of metals continues to rise, even more plentiful metals, may face similar depletion in the near future. (Kibert 44)

A Rational for Green Building

Although the deep green movement would return us to a pre-industrialized world, functioning as an organic agrarian society, more pragmatic green building ideologies extend from the industrialized foundations of a post-industrial world. (Ferrera and Visser 14) Today’s green builder balances the needs to reduce cost and improve the quality of living for occupants with an ethical and practical response to issues of environmental impact and resource consumption. (Kibert 5)

Green building virtually always makes sense on a life-cycle cost basis. Significant savings and improved product unity of the building occupants can be realized for the life of the building, lowering the total cost of ownership. (Kibert 5) Furthermore, as energy and water prices continue to rise in response to growing demand, payback periods will decrease. Conventional construction methods usually pay little attention to the potential affects on occupants such as sick building syndrome (SBS), building-related illness (BRI), or multiple chemical sensitivity (MCS). (Kibert 5) In contrast, green buildings are designed to promote occupant health and well being by utilizing such measures as zero volatile organic materials, ultraviolet radiation in ventilation systems, as well as careful selection and installation of ductwork and piping.

Green building serves to protect and foster the natural environment through integration of native and adapted species in landscaping, while encouraging the use of renewable resources; recycling and reuse of water and materials; passive energy systems; and other approaches that minimize environmental impact and resource consumption. (Yudeison 13)

A Resource-Conscious Design
Green building employs a resource conscious design, which aims to minimize natural resource consumption and impact on ecological systems. From resource extraction through disposal at the end of the materials useful life, green building practices account for the entire building life cycle, its constituent components, and how they impact the environment. (Kibert 5)

Land Resources
Land, particularly undeveloped, is a finite resource, and its development should be minimized. Former industrial zones (brownfields) and blighted urban areas (grayfields) should be recycled back to productive use, precluding further development while promoting economic and social revitalization in distressed urban areas. (Kibert 7)

For instance, in 1997, the Cirque du Soleil endeavoured to revitalize a proposed dumping site on the periphery of Montréal. Since then, other groups have joined in establishing the Cité des arts du cirque, a community for producing and promoting the circus arts. (Ferrera and Visser 74) Site conservation measures includes a non excavated basement and a minimal removal of excavated material. Moreover, through an agreement with the local company Gazmont, biogas Gas from an excavation site at the Saint Michelle environmental Complex is converted into energy used in the Cirque du Soleil’s heating systems.

Energy and Atmosphere
Because energy sources such as coal or oil cause a significant portion of air pollution and climate change, (Haselbach 119) energy conservation is best addressed through affective building design, which integrates three general approaches: designing a building envelope that is highly resistant to heat transfer; using renewable energy; and implementing passive design which employs the buildings geometry, orientation, and mass to condition the structure using natural features such as the sites solar insulation, thermal chimney effects, prevailing winds, local topography, microclimate, and landscaping.

For example, Montreal’s Mountain Equipment Co-Op Store incorporates solar and geothermal energy radiant heating/cooling, a natural ventilation and uses at least 65% less energy than a similar reference building. Building system controls retrieve weather forecasts via the Internet and are able to accordingly adjust the thermal mass of the structure. (Ferrera and Visser 68) Window sizing and location was determined using computer simulations to optimize natural lighting and control thermal heat gain.

Water Resources
Since only a small portion of the earth’s hydrological cycle yields potable water, protection of existing ground and surface water supplies is increasingly critical. Water conservation techniques include the use of low flow plumbing fixtures, water recycling, rainwater harvesting, xeriscaping, a landscaping method that utilizes drought-resistant plants and resource-conscious techniques. Innovative approaches to wastewater processing and storm water management should address the full scope of a building hydrologic cycle. (Kibert 8)

Within the framework of the L.E.E.D. Canada rating system, the Université du Québec à Montréal [UQAM] Biological Sciences Pavilion implements several water conservations strategies that reflect the university’s commitment to environmental responsibility and leadership. Rainwater is collected for use in toilets and landscaping irrigation. Waterless urinals and low flow fixtures reduce potable and wastewater volumes. Landscape vegetation includes indigenous species requiring low maintenance and no winter protection, which aid in the protection and preservation of existing natural hydrological cycles. (Ferrera and Visser 132)

Ecosystems: The Forgotten Resource
Integration of ecosystems with the built environment should play an important role in resource conscious design and supplants conventional technologies in controlling external loads, processing waste, absorbing storm water, growing food, and providing environmental amenity. (Kibert 9)Smith Carter Architects and Engineers Incorporated of Winnipeg features preservation of existing mature trees, a storm water detention pond, walking paths and restoration of native planting and local bird habitat. The site preserves 150 mature to spruce trees and restores 1.4 acres to native prairie grassland, promoting biodiversity. Air intake is on the tree side of the building, so that fresh air is scrubbed by the spruce forests before entering the building. (Ferrera and Visser 70)

Schedule
Although project schedules may differ depending upon the type of project and construction process used, the stages of a project can be summarized into a few main categories: project conceptualization; schematic design; planning and zoning and other municipal planning organization reviews; detailed design development; permits; construction document development; bid and procurement; construction; close out; and operations. (Haselbach 277) The bar chart in figure below shows the project timeline of a typical green construction project. (Haselbach 281)

Budget
As show in figure, additional design and certain green features may add as much as 0.7% to 2.0% of total building cost (Swift 6), however, experienced practitioners of green design such as Victor Courte, president of Courte construction note: “the front-end costs are higher due to design and commissioning, but ultimately lead to energy efficiencies, resulting in a net savings over the life of the building. Furthermore, a recent study by The American Chemistry Council estimate of soft costs of obtaining LEED certification is 2.3 percent of total construction costs with a range of 1.5 percent to 3.1. (ACC)

Qualifications
As building, civil, and environmental engineers, we are taught how to create mathematical computer models that are used to judge alternatives, provide creative input, and assist with development of new techniques and solutions. (Swift 82) Building and civil engineers are invaluable in building design orientation considerations, form and dimension, and deciding which type of materials will provide the maximum quantity of solar radiation, while at the same time analyzing the heat transfer characteristics of those options. Building and civil, in conjunction with environmental engineers find ways to reduce the facilities potable water, sewer, storm water conveyance requirements, while protecting and preserving the natural environment.

Sources of Information

American Chemistry Council (ACC) , Analyzing the Cost of Obtaining of LEED Certification, April 16, 2003,
http://www.cleanair-coolplanet.org/for_communities/LEED_links/AnalyzingtheCostofLEED.pdf.
Courte, Victor. President, Courte Construction. Interview, Montreal, July, 2008.
Ferrera, Luigi and Visser, Emily, ed. Canada Innovates: Sustainable Building. Toronto: Key Porter Books Limited, 2008.
Haselbach, Liv. The Engineering Guide to LEED – New Construction. New York: McGraw – Hill,2008.
Kibert, Charles, J. Sustainable Construction. New Jersey: John Wiley & Sons, Inc., 2008.
Swift, John, M. et al. EASHRAE Green Guide. Atlanta: Elsevier, 2006.
US Green Building Council (USGBC). Green Building Research, July, 2008, n.p., http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1718.
Wikipedia. Green Building. July, 2008, n.p., http://en.wikipedia.org/wiki/Green_building.
Yudeison, Jerry. The Green Building Revolution. Washington: Island Press, 2007.

Environmental Impacts from Weirs

2009-08-08T11:12:00.011-04:00

A weir is any control or barrier placed in an open channel to permit measurement of water discharge. Weirs provide hydrologists and engineers a simple way of measuring the rate of flow in small to medium-sized streams, or in industrial discharge locations. Since the geometry of the weir is known, and all water flows over the weir, the depth of water behind the weir can be converted to a rate of flow.

A weir typically increases the oxygen content of the water as it passes over the crest and it can effect the local ecology of a river system. A weir will artificially reduce the upstream water velocity, which can lead to increased siltation. The weir may pose a barrier to migrating fish. For these reasons, an environmental impact assessement is usaully necessary before construction.

Geo-Environmental Engineering - Soil Sampling

2009-08-04T16:14:00.010-04:00

Concordia University
Department of Building, Civil, and Environmental Engineering
Geo-Environmental Engineering Laboratory - Soil Sampling with Dr. Maria Elektorowicz

Photographs and video demonstrating soil sampling techniques for shallow contamination.

Water Purification Tip For Campers

2009-08-01T13:01:00.024-04:00

If you are going on a portage, you will have to bring along some form of water treatment to combat the ever increasing pollution entering our natural watercourse. There is always the tried and true way of using iodine tablets and boiling, but that's energy intensive and doesn't exactly produce the most potable water available using other techniques. Over the course of many decades, we've kept pace with the latest technologies and gadgets as they've progressed from water filters into certified water purifiers.

We have been using the First Need Portable Water Purifier for three years and it has been on at least a dozen back country portages. It has never broken down and we have been able to produce a 6 day supply of potable water for groups of 8 people using a single cartridge and the method below.

Before discovering the First Need Purifier we used pharmaceutical grade vaccine filters which I was able to get from work, but the principles are exactly the same. Use a set of small pulleys to hoist a container marked "Contaminated". Attach a piece of tubing to the inlet of the water purifier and another piece of tubing from the water purifier outlet to a second container marked "Potable" or something descriptive. Give the water purifier a few pumps and let gravity take over. Now you'll have more time for what's important and should be able to produce about 5 gallons of potable drinking water every 4 hours with little effort.

Update: Help Your Pets Make Better Choices

2009-07-31T09:44:00.034-04:00

An earlier post Help Your Pets Make Better Choices left off by mentioning some ways of improving your pets drinking water. One of them was to begin filtering out suspended particles left behind after the aeration process. Having returned to the pet fish section at Wallymart for inspiration, a simple and effective solution comes from the same technology used to provide healthy aquatic environment for little Nemo: the Internal Filter.

In addition to providing aeration, the activated carbon filters help remove much of the suspended particles that we are targeting and all of the sediments and light particles left behind after visits to the bowl. The model we used is air driven and our air pump has two outlets so it fits in well with our existing setup. Keeping the bowl full improves efficiency and it's much easier to replenish a dish than wash it twice a day, healthier for your pet, and easier on the environment.

The next stage is to coordinate some lab time and start collecting samples and data to determine how effective this process is and for how long it can operate before the filter needs changing.

Five Solar Garden Light Upcycle Ideas

2009-07-01T07:00:00.007-04:00

The sun is the greatest source of renewable energy we have and solar garden lights are a dime a dozen. So its no wonder, more and more people are finding useful second lives for these innocuous contraptions. Here are five amazing do-it-yourself projects that turn ordinary solar garden lights into cool eco-friendly gadgets you'll use everyday.

Before getting started, check out this great solar yard light deconstruction tutorial from Marshal Brian, founder of Howstuffworks.com, which clearly illustrates the parts, functions, and inner workings of a typical solar garden light.

1. Solar Powered USB Ipod/Cell Phone Charger

This Instructable shows how surprisingly simple it is to make a solar battery charger from very simple components. If you are looking for something universal, check out the video below from WonderHowTo.com showing how to turn an ordinary solar garden light into a renewable energy backup system for today's power hungry cell phones, Ipods, and gaming gadgets.

2. Bottle the Sun's renewable energy

Jam jars store jam, the Sun Jar collects and stores sunshine so that you can use it at night or to recharge batteries. Check out the Sun Jar from Suck.uk.com, then head over to Instructables for a step-by-step on how to bottle your own. If you have solar path lights and live in a cold climate where they don't get much use in the winter, this is an easy and efficient way to keep rechargeable batteries topped off and well maintained while not in use.

3. Architectural and decorative lighting

This is a simple thing you can do with a set of solar path lights to turn them into portable lanterns or retrofit existing outdoor lamp posts to use renewable energy. Here is another idea that uses the solar light circuit to suck every last bit of energy out of otherwise dead alkaline batteries before disposal. Makes a great night light.

4. Sports equipment

This simple project converts two solar garden lites and some PVC into a pocket sized LED solar powered lamps that can be used as a night/comfort light or reading lamp. The finished lamp is water proof, will float and will last virtually forever, making them great for camping. Modify a solar garden walkway light into a solar powered bike light that charges during day riding and can be turned on at night!

5. Renewable Energy Power Plant

This is a Solar Power Plant made from recycled parts. It is a work in progress that started at the landfill where you'll find all kinds of interesting electronics gadgets ready to be harvested for project parts. The cells charge a 12V car battery which is used to supply 120V through an off-the shelf inverter for light loads. Makes an excellent power supply for laptops, lights, or radios during power outs. Use it run an outdoor lighting system or plug it into this universal charger and turn in those crappy chargers that came with your gadgets for a more environmentally friendly, cheaper solution.

Winter is a good time to hunt for bargains on solar lights. When shopping for a solar garden light its a good idea to look for ones that have two or more AA Ni-Cad batteries and a photo resistor for detecting darkness. More batteries generally means the circuit can provide higher output for your projects and a photo resistor will allow you to incorporate light sensing into your gadgets if needed.

There are so many ways to hack a solar light and I've only mentioned a few. In an upcoming post I'll take a look at some additional ideas of incorporating solar lights with other off the shelf items to create even more interesting, functional, and eco-friendly gadgets. Thanks for stopping by.

Upcoming visit to world's largest hydraulic lift lock

2009-06-29T07:00:00.004-04:00

I'll be attending a family reunion this week in Peterborough and although the schedule doesn't leave much time for work, there's no way I'm missing an opportunity to visit the worlds highest hydraulic lift lock and take in this engineering marvel.

According to Parks Canada Lift Lock 21 is the highest hydraulic lift lock in the world rising 19.8 m (65 ft). Moreover, the lock uses gravity and a cantilever to do all the heavy lifting. No external power needed! Stay tuned for more updates...

5 L.E.D. Projects Sure To Enlighten

2009-06-27T09:00:00.010-04:00

As a Canadian I’m reluctant to admit we use more energy per capita than any other nation in the world and although we have plenty of cheap, renewable electricity, it’s wasteful, both in cost to the environment and the family’s budget. It’s true we’ve been making the switch to compact fluorescent (CFLs) from incandescent bulbs, but they still cost more than standard bulbs and contain mercury which is an environmental concern if not disposed off properly.

Light Emitting Diode (LED) technology, however, uses a fraction of energy compared to conventional incandescent or even CFLs. They last up to 50,000 hours, compared to 6,000 for a CFL or 1,000 for standard incandescent bulbs. LEDs convert more electricity into light, with very little waste heat produced, making them the most efficient lighting technology available on the market. Here are five eco friendly ideas with step-by-step instructions that shine a light on LED technology.

1. Make a Joule Thief that runs off dead batteries.

In case you haven't heard of this, a Joule Thief is a tiny little circuit that lets you drive a white or blue LED from otherwise dead batteries, squeezing every last drop of energy out of them! If you decide to embark on this project, check out another Instructable on how to recycle parts from dead CFL bulbs. Once your done, turn them in to Cyborg zombies.

2. Grow year round with LED

Create a simple light system to keep houseplants thriving during the short winter days. You can even power it with the JouleThief. If you're looking for something with a little more power, check out }{itch's Instructable using high power Phillips Lumileds for his grow light. Incidentally, the same technology is used in chromotherapy to treat seasonal affective disorder and other ailments.

3. Let your artistic side shine through

Photographer Stuart Nafey and artist Lori Stotko create Light Doodles with custom-made LED pens. Check out their work on Flickr, and a step-by-step Instructable on how to make your own LED pens, then let your imagination run wild.

4. Burn the midnight oil ecologically.

Quick and easy steps to making a USB powered LED Light perfect for late nights in front of the computer. For something more powerful check out this halogen fixture retrofit that uses less than 10W, lasts 50,000 hours, and produces just much light as its counterpart.

5. Make a statement with LED Throwies

Developed by the Graffiti Research Lab, LED Throwies are an inexpensive way to add color to any ferromagnetic surface in your environment. A Throwie consists of a small lithium battery, a 10mm diffused LED and a rare-earth magnet taped together. Throw it up high and in quantity to impress your friends and city officials. Don't forget to pick up.

Summer is a good time of the year to harvest Christmas LED ornaments lurking in the discount bins of department stores for these projects. Likewise, winter is usually when I find the best bargains on solar path lighting gadgets which will be the topic of another post. It's incredible what you can do with a solar garden light and a disposable camera - automatic racoon zapper! Stay tuned...

Beat the Summer Gas Crunch - Hypermiling Techniques

2009-06-23T08:10:00.011-04:00

If done properly, the average driver can beat the Transport Canada Combined Fuel Consumption Rating (CFCR) of his or her vehicle by 40-50% this summer by applying a few simple hypermilling techniques.

Tire pressure

You’ve heard this one before. Higher tire pressure means lower rolling resistance, better fuel economy, and longer life. Installers will usually under inflate tires for a more comfortable ride, but it is practical to inflate tires closer to the maximum rating found on the sidewalls. Service your tires regularly and ask your mechanic to use nitrogen instead of air. Nitrogen is lighter than air, leaks less than air, prohibits rust, and has added safety and mechanical benefits making it a smart alternative. Nitrogen is available at Canadian Tire and is free at Cosco service centers in Canada.

Tuned engine and mechanical parts

A poorly tuned engine can result in a 40% decline in fuel economy and can produce significantly more emissions than allowed by law. Reducing friction and vibration can be the most important aspect of your fuel economy. Have unusual noises checked out. A well oiled machine runs efficiently and if left un-serviced, builds up friction forces reducing efficiency. Use synthetic oil when possible to reduce engine wear and pollution. Maintain the engine’s air filters regularly by shaking or vacuuming out particles.

Trim the fat

Carrying unnecessary loads around adds up. Reducing your load by 100lbs can reduce your fuel costs by 2%. Clean out the trunk, remove roof racks, and any other items not being used. Consider keeping the fuel tank half full and if you’re the only person driving your car think about removing back seats, plastic covers, and whatever else you don’t actually need as a next step.

Accelerate slowly

Tests by Edmonds.com show accelerating from 0 to 60 in 20 seconds from stoplights and stop signs can cut fuel consumption by around 37% for SUVs. You won’t win any drag races, but that’s plenty of time to enter freeways and highways without incident.

Practice smart braking

More energy is required to get your car moving from a dead stop than to sustain motion so a big challenge for hyper-milers is learning how to avoid stops. Let off the gas ahead of stops and let your car role in neutral, only applying the brakes as needed. At red lights, leave the car in neutral (if it has an automatic transmission). At stop signs, try not to come to a dead stop, but let the car creep along, until it’s safe to continue.

Follow the leader

The reason is aerodynamic: a flow of traffic generates a localized wind current in the direction of travel. You will benefit from this artificial breeze. Drive at a steady pace and don’t tailgate.

Cruise control

Contrary to popular belief, cruise control is less efficient than constant throttle/load driving techniques where you manually tweak the accelerator. Set the cruise control if your speed creeps up on long trips or you have difficulty holding a constant speed.

Don't idle unnecessarily

If you’re stopped for more than 7-seconds, turn the engine off. Today’s fuel injection systems are efficient, typically using about 5 seconds of fuel to start the engine. You may not make friends with the guy behind you at the drive-through, but try not re-starting the engine until you absolutely have to.

Air conditioning

The air conditioner increases fuel consumption by more than 20%. Consider rolling the windows down or using solar powered air vents. If you have to use the air conditioner, set the vehicle’s air flow to recirculation, switch it on when under light engine loads or deceleration, and off when under moderate or heavy loads.

Hold the inside lane

Holding the inside lane around long curved sections of freeway can make a difference over the long haul. By taking the shortest route around curves you will shave about 1% off the travel distance on a three lane highway each time, which adds up over the life of your vehicle.

And then there are always the old fashioned ways to save money on gas like carpooling and using public transit. Don’t forget those either!

DIY Solar Lawn Mower

2009-06-22T06:49:00.008-04:00

We all know that mowing our lawns with gas mowers creates an enormous amount of air and noise pollution. In fact the average gas mower creates as much air pollution as driving the family car on a 200 mile trip and we all know how annoying they sound when you are trying to sleep in on the weekend.

I was doing some research on solar lawnmowers, looking for somebody that’s hacked an old Sunbeam electric cord mower to run off solar power. Having endured ridicule from friends and neighbors long enough, I thought it was finally time to cut the cord for good and breathe new life into an otherwise great machine. What was I thinking! It turns out old green won’t be coming out of retirement without some serious retrofit, time, and money.

A much more elegant solution is to find a used battery powered lawn mower, and simply attach a cable for a solar panel to the rechargeable batteries. It’s less expensive or labor intensive and a project anyone can handle. This Instructable shows how to retrofit an electric mower with a solar panel for charging. Have fun!

Technology Without Risk

2009-06-14T07:03:00.010-04:00

As the wheels of technology churn out exponentially complex systems designed to lightened man’s burden and propel society upwards and onwards, in turn much of society has little or no bearing on which direction we are heading or how far we may fall. We leap without looking, and while escaping the naiveté of our technological childhood, we have more recently become aware that the complexity and pace of the derived technology has resulted in an increasing frequency and severity of catastrophic disasters.

Consequently, while risk acceptance remains a social decision [1 45], the science of risk management which takes into account the actual risks and the general public’s negative perceptions of the risk stemming from a lack of faith in the political systems set up to fill the gap, whether they be technological or human, are diverging. This isn’t to say that technology and society cannot coexist without risk. It is this author’s and others belief that risks can be mitigated to acceptable levels, but the social perception of said risks must also be understood by all of the players for a proper assessment to be formulated and meaningful progress to take place.

While the early successes of trial and error [2 53] engineering resulted in marvels of science like the Egyptian pyramids right up to the civil infrastructure of the 19th century, more recent catastrophes (plane crashes, bridge collapses, epidemics) preclude any engineering design from foregoing rigorous documentation; qualification, validation, and life cycle assessment. Case in point; the Hubble Space Telescope Systems Engineering Study [3] conducted by Mattice in March of 2005 illustrates the level of regulatory and voluntary documentation required for any modern engineering project and the need for guiding principles that meet the needs of end users through participation and transparency.

Moreover, a persistent quest for improvement and consequently, an increasing level of skill is required as the best defense against unforeseen failure. For it seems history has taught us the unforeseen failures are in the details [2 95]. All too often we are reminded of catastrophe due to some innate part of a larger system like the failure of the Hubble Space Telescope due to manufacturing defect of a single component or the collapse of the Hyatt Regency elevated walkway due to an engineering blunder [2 85]. These are failures of the human mind and the catastrophes that ensued may have been eschewed had the rigorous tasks been performed with focus on the details. We must keep an ever watchful eye on technology and challenge our assumptions continuously, for each new innovation spawns unforeseen risk, which if left unchecked is simply passing the buck to future users.

The Role of Economics & Policy

As a Quality Engineer Specialist at Merck with 15 years experience in the pharmaceutical industry I was able to witness the birth of FDA policy enacting regulation on pharmaceutical manufacturers to perform retrospective validation for existing products. In later years, the FDA’s policy was expanded to include prospective validation, qualification, life cycle assessments, and a host of other documentation standards required by manufacturers to enumerate and abate health and environmental risks. Until that point, however, quality was confined to real time control charts and monthly quality circle meetings, but no insights were ever gained from this process. It wasn’t until FDA policy requiring all manufacturers to perform these tasks using data as far back as possible that we began to see patterns and clear trends towards unforeseen failures. To remedy these risks, Merck formed the Quality Engineering Group in which I worked over the course of my employment and to which we were widely successful towards improving safety and efficacy of our product line.

All this was at a great cost to the company, but quality improved tremendously, complaints were down, and quality above profits was then and remains Merck’s mantra. However, as the years went by, the strides in quality our department could make began to diminish and it became clear that the point of no return was approaching. We had gained extensive knowledge and control of the processes and were able to reduce variability of critical quality control parameters to less than 1 sigma in many cases. This information was shared across Merck’s network and with other teams from across the globe we were able to bridge cultural, political and economical differences towards a common goal. Although, continuous monitoring remains an essential task, we had extensively created a zero defect process and it was no longer pragmatic to continue our research. It wasn’t long after, management began to realize any future improvements would only be gained from serious investment and the company began to shift globally to a one plant - one product process. In doing so, they were able to benefit from the technology we had envisioned, reduce operating costs significantly, and allow each unit to focus on the most minute details of its operation (improve quality). Whence, I and many others found ourselves without a job. But the final insult came more recently when Merck announced they were closing the doors on the very workshop here in Montreal that led the zero defect revolution and was the epitome of quality within the industry during its reign all together; presumably for lower wages, free markets, and a chance to influence the policy of emerging nations, but I digress.

The lesson learned is policy can be the impetuous towards risk free technology. If the commitment remains as in the case of Merck, there are sure to be guinea pigs along the way, however, the result is better quality for the long run and a step towards a risk free technology. As Bulte reiterates in Economic Incentives and Wildlife Conservation [4 2], policy in the form of economic incentives, regulation, or moral suasion are the tools strategists have at their disposal towards stimulating and enforcing risk reduction. In Merck’s case the proof lies in the founding fathers own words: “We try never to forget that medicine is for the people. It is not for the profits. The profits follow, and if we have remembered that, they have never failed to appear." –George W. Merck, 1950. The moral and economic lessons are evident early on, yet even with such a failsafe vision, it wasn’t until regulation forced the corporate mentality into a new way of thinking that meaningful strides in quality were to be realized, some 40 years later.

Producers of technology like Merck and others now realize a zero defect product is achievable and that what follows are healthy profits in the long run. There are generally heavy upfront costs towards instituting and maintaining zero defect systems, so it’s necessary for economic incentive to be present where the rationalization or realization is beyond the scope of emerging technologists. Once rooted, technology is drawn towards quality in a free market and is improved upon as far as the market is willing to afford it. To these ends economics and policy are essential elements of a risk–free technology.

References
[1] Wenk, E. Technology and Risk, University of Illinois Press, 1995
[2] Petroski, Henry, Success is Foreseeing Failure, Princeton University Press, 2006
[3] Mattice, James. Hubble Space Telescope Systems Engineering Case Study,AFIT, 2005
[4] Bulte, Erwin H. Economic Incentives and Wildlife Conservation, Tilburg University, 2003