Can You Sustain?

Standby Decanter

2013-03-21T16:58:00.000+08:00

Introduction
The purpose of Continuous Improvement Project (CIP) is to install temporary floating decanter for SBR plant. There are a few types of decanter were currently equipped at SBR plant. SBR have faced a lot of cases of decanter breakdown especially for arm type decanter. Unlike wastewater pump, installation of decanter at SBR plant never provide standby thus when a unit of decanter breakdown, STP operators have to mitigate the situation in order to keep process sustainability at required level. Failure to have proper action and meeting regulatory compliance will escalate operator into authorities action.

INSTALLATION
The temporary floating decanter will be installed according to depth of decant about 0.8m to 1.2m from top water level. The pump must be provided with a horizontal base baffle plate and attached to the bottom pump cage to minimize direct suction of settle suspended solid inside SBR tank. The temporary decanter outlet pipe must be higher than water level to prevent siphon condition.

Power source of existing decanter will be diverted to the temporary floating decanter, however some modification required especially on the contactor and overload according to power requirement by the pump. The pump should receive operation signal from PLC or main programming in order to replace function as decanter.

MODIFICATION

In order installation meets objective, some modification on PLC is required to disable certain interlock such as upper and bottom limit switch of existing decanter. The pump will start when the SBR system has completed the ‘settling’ stage. In some cases, timer counter for SBR programming system is required for the pump to limit its operation just after settling stage and before aeration stage.

Float switch installation may also important to cut off pump operating whenever water at lower pumping level.

What is SBR?

2012-12-21T10:16:00.004+08:00

SBR is short term of Sequential Batch Reactor. SBR recognize as one of the economic design of wastewater treatment plant due to land area and structure cost saving. However, decisions should not be based solely on economics but should also include process flexibility, ability to meet permit limits, and long-termviability.

SBR is an activated sludge process. Common of SBR process were illustrated as below:

There are 4 main stage completing SBR process for wastewater treatment.

Stage 1:
Filling stage – Wastewater will enter into reactor tank (normally square size) after primary treatment (primary screening, secondary screening, grit and grease removal).

Stage 2:

Reaction stage – The wastewater will be air-injected (aerated) and mixed, purposely to provide oxygen to microbe (endogenous Heterotroph bacteria and protozoan) which decompose organic matter (BOD components) for growth in aerobic conditions. The existence of microbe may observe virtually through brownish water (suspended solid/sludge) during this stage.

In Malaysia, Stage 1 and stage 2 were preceded parallel.

Stage 3:
Settling stage – Filling and reaction (aeration and mixing) no more in place during this stage. The condition allows stagnant water whereas suspended solid will settle bottom inside the reactor. Two obvious liquid layer existed which top is clear treated water and bottom is sludge. By completely assuming here, more compacted sludge is flocculated and ready for return or waste.

Stage 4:

Decanting stage – Removing clear treated water (effluent).

RIVER OF LIFE

2012-11-29T09:17:00.001+08:00

Malaysia currently undergoes significant transformation of reservation of water sources by river cleaning, beautification before year 2020. It is put Listed under Greater KL project to increase high economic value.

Greater KL project include transformation of sewerage treatment line and facility, to enhance operation and services.

NOT many would believe that there is an impending water shortage in Malaysia, especially if they are Kuala Lumpur folks who are often caught in traffic jams caused by downpours. But if climate change alters the favorable rainfall pattern, we will have to come to terms with water rationing or other drastic water conservation measures. - according to THESTAR

Rivers have long been recognized as one of humanity’s most important natural resources. They are one of the most important of all the natural resources necessary to ensure human health and civilization. A close association between cities and water is inherent over the history of civilization and in fact, many urban cities in Malaysia are located close to river areas. The last two decades have shown Malaysia has shifted development strategy from an agricultural base to industrialization, and manufacturing industries have now become the main component of the economy for the country. This transformation since the 18th century has clearly shown that rapid urbanization, industrial and intensive agricultural activities, as well as wide-spread land development, have contributed to extensive changing of river functions for the economy, national development and the environment. In particular, river roles have become less significant for human life and river functions limited to transportation purposes only.

Environmental Management System (EMS)

2011-11-02T08:46:00.001+08:00

What is EMS?

An environmental management system is the process used by an organization to manage, review, correct, and improve the organization’s approach to business. Employees are asked to consider how they affect the environment every day. An EMS offers a structured way to incorporate environmental considerations into day-to-day operations; it promotes continual improvement of the environment and human health.

EMS key all about

1. Systematic way of managing an organization's environmental affairs

2. Based on Plan-Do-Check-Act (PDCA) cycle. Some EMS approach being made Policy-Planning-Implementation- Checking corrective action- Management review.

3. Focussed on continual improvement of system

4. Addresses short term and long term impact of a product or services provided by the company to environment

5. A tool/method to improvement environmental's performances

Conducting EMS in an organization require commitment from all department. Some senior management likely stepping back to commitment because EMS depending on voluntary approach.

Conducting EMS in an organization will reduce waste, increase process effieciency, increase environment safety, eliminate insurans claims, provide uniform operations, increase productivity and saving operation cost.

What is Hydraulic Retention Time

2011-07-25T16:07:00.002+08:00

The Hydraulic retention time (HRT) also known as Hydraulic residence time or t (tau), is a measure of the average length of time that a compound remains in a constructed reactor.

Hyraulic retention time is the volume of the aeration tank divided by the influent flowrate:

HRT represent differently according to type of bioreactor. HRT is usually expressed in hours (or sometimes days).

Phosphorus Removal in Activated Sludge Process (by PAOs)

2011-06-02T09:03:00.002+08:00

In Anaerobic Treatment Tank

1. Polyphosphate accumulating organisms (PAOs) decompose polyphosphate (PP) and produce orthophosphoric acid (called orthophosphates)

2. By decomposing, PAOs gain energy and assimilate organic substances (volatile fatty acid, acetate). It is accumulated in PAOs body as polyhydroxoalkanoate (PHA) (called polyhydroxybutyrate, PHB)

In Aerobic Treatment Tank

3. PAOs decompose PHA which earlier stored in their body

4. By decomposing, PAOs gain energy (live and grow) and uptake orthophosphoric acid and accumulate in PAOs body as PP

5. Phosphorus element being discard from system through wasting (WAS) PAOs from final sedimentation tank.

Preparation of Dewatering Polymer

2011-03-17T15:14:00.000+08:00

Procedure 1: Preparation of dewatering polymer (0.1%)

1. Fill polymer mixing tank with tap water (500L, 1000L, or 1500L).

2. Weight dry powder polymer (0.5kg, 1.0kg or 1.5kg)

3. Start polymer mixer and run continuously.

4. Pour the weighted dry polymer slowly into moving water. Be careful during pouring to prevent bulk powder entering the water and dust from flying over.

5. Mix the solution (dry powder polymer + water) 45 minutes to 1 hour until homogenous solution achieved (no powder/particle suspended in the solution).

Working Flow of Energy Saving at Sewage Treatment Plant

2010-11-15T12:41:00.002+08:00

Characteristic of Protozoa in Activated Sludge Process

2010-07-03T20:41:00.007+08:00

Group 1, 2 and 3 : Characterize of young sludge inside activated sludge process

The protozoa consist of predominate Amoebae and flagellates with a few free swimming ciliates.

Group 4: Characterize of mature sludge inside activated sludge process

For municipal wastewater treatment plants the most desirable stage of the ecological succession is the stage where both stalked ciliates and free swimming ciliates are observed with possibly a few rotifers. This stage is is correlated with rapid settling of solids and easy separation of solids from water. The resulting effluent is correspondingly low in turbidity, suspended solids and biochemical oxygen demand (BOD).

Group 5: Characterize of old sludge

Predominating of rotifers and nematodes with fewer stalked ciliates.

Examples of group 4 protozoa: Vorticella and Epistylis

Floating Scum Skimmer

2010-03-31T10:42:00.002+08:00

Material to construct floating skimmer ? Water engineers are likely focussing on studying density values of PE polymers .

UHMWPE is polyethylene with a molecular weight numbering in the millions, usually between 3.1 and 5.67 million. The high molecular weight makes it a very tough material, but results in less efficient packing of the chains into the crystal structure as evidenced by densities of less than high density polyethylene (for example, 0.930–0.935 g/cm3). UHMWPE can be made through any catalyst technology, although Ziegler catalysts are most common. Because of its outstanding toughness and its cut, wear and excellent chemical resistance, UHMWPE is used in a diverse range of applications. These include can and bottle handling machine parts, moving parts on weaving machines, bearings, gears, artificial joints, edge protection on ice rinks and butchers' chopping boards. It competes with Aramid in bulletproof vests, under the tradenames Spectra and Dyneema, and is commonly used for the construction of articular portions of implants used for hip and knee replacements.

HDPE is defined by a density of greater or equal to 0.941 g/cm3. HDPE has a low degree of branching and thus stronger intermolecular forces and tensile strength. HDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. The lack of branching is ensured by an appropriate choice of catalyst (for example, chromium catalysts or Ziegler-Natta catalysts) and reaction conditions. HDPE is used in products and packaging such as milk jugs, detergent bottles, margarine tubs, garbage containers and water pipes.

PEX is a medium- to high-density polyethylene containing cross-link bonds introduced into the polymer structure, changing the thermoplast into an elastomer. The high-temperature properties of the polymer are improved, its flow is reduced and its chemical resistance is enhanced. PEX is used in some potable-water plumbing systems because tubes made of the material can be expanded to fit over a metal nipple and it will slowly return to its original shape, forming a permanent, water-tight, connection.

MDPE is defined by a density range of 0.926–0.940 g/cm3. MDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. MDPE has good shock and drop resistance properties. It also is less notch sensitive than HDPE, stress cracking resistance is better than HDPE. MDPE is typically used in gas pipes and fittings, sacks, shrink film, packaging film, carrier bags and screw closures.

LLDPE is defined by a density range of 0.915–0.925 g/cm3. LLDPE is a substantially linear polymer with significant numbers of short branches, commonly made by copolymerization of ethylene with short-chain alpha-olefins (for example, 1-butene, 1-hexene and 1-octene). LLDPE has higher tensile strength than LDPE, it exhibits higher impact and puncture resistance than LDPE. Lower thickness (gauge) films can be blown, compared with LDPE, with better environmental stress cracking resistance but is not as easy to process. LLDPE is used in packaging, particularly film for bags and sheets. Lower thickness may be used compared to LDPE. Cable covering, toys, lids, buckets, containers and pipe. While other applications are available, LLDPE is used predominantly in film applications due to its toughness, flexibility and relative transparency.

LDPE is defined by a density range of 0.910–0.940 g/cm3. LDPE has a high degree of short and long chain branching, which means that the chains do not pack into the crystal structure as well. It has, therefore, less strong intermolecular forces as the instantaneous-dipole induced-dipole attraction is less. This results in a lower tensile strength and increased ductility. LDPE is created by free radical polymerization. The high degree of branching with long chains gives molten LDPE unique and desirable flow properties. LDPE is used for both rigid containers and plastic film applications such as plastic bags and film wrap.

VLDPE is defined by a density range of 0.880–0.915 g/cm3. VLDPE is a substantially linear polymer with high levels of short-chain branches, commonly made by copolymerization of ethylene with short-chain alpha-olefins (for example, 1-butene, 1-hexene and 1-octene). VLDPE is most commonly produced using metallocene catalysts due to the greater co-monomer incorporation exhibited by these catalysts. VLDPEs are used for hose and tubing, ice and frozen food bags, food packaging and stretch wrap as well as impact modifiers when blended with other polymers.

Recently much research activity has focused on the nature and distribution of long chain branches in polyethylene. In HDPE a relatively small number of these branches, perhaps 1 in 100 or 1,000 branches per backbone carbon, can significantly affect the rheological properties of the polymer.

Water which is denser than HPDE , will cause HPDE to float on water surface , thus floating scum will be collected to floating skimmer system.

Water Resources Planning and Development

2010-03-20T02:17:00.000+08:00

Water resource assessment for sustainable development and management

Kuala Lumpur, like other States in Malaysia, remains concerned over a possible water shortage in the near future in view of unevenly distributed rainfall and growing pressure on water supplies for domestic and industrial purposes. To overcome the problem in Kuala Lumpur, interbasin or interstate water transfers are expected to become an increasingly common feature of water resources development planning.

Kuala Lumpur is relatively small in geographical terms, and city developments are often small but intensive. Thus there are likely to be many development projects for which EIAs will not be mandatory simply because the relevant gazetted definitions are generally defined by area. It would therefore be prudent to apply the EIA procedure to all development in Kuala Lumpur, especially those in identified or listed environmentally sensitive areas.

Under the Seventh Malaysia Plan (1996-2000) a new national study will be undertaken to identify potential water resources, carry out feasibility studies of water resources development projects and formulate a long-term national master plan with an integrated approach to the development and management of those resources. The study will assess the quality and quantity of water in all States, including Kuala Lumpur, for domestic, industrial, irrigation, hydropower and other uses for the years 2000 to 2050. The results of the study are expected to enable the government to plan an overall priority programme for phased development of the recommended water resources projects.

Meanwhile, various prudent strategies and development programmes are being undertaken in Kuala Lumpur, including:

The control and reduction of non-revenue water through the rehabilitation and upgrading of existing water distribution systems;

The rehabilitation and upgrading of existing water treatment plants;

Improvement of systems supplying water to existing industrial areas.

In addition, under the Seventh Malaysia Plan, a continuing effort is being made to ensure that the development of water supplies is sustainable and balanced. For Kuala Lumpur/Selangor, two programmes with a capital investment cost of M$ 560 million have been proposed.

The current programme for rehabilitating and upgrading water supply systems, which is being further expanded under the current plan period, is to:

Restore the production capacities of water treatment plants to their original designed capacities and, where feasible and economical, increase that capacity through modifications or additions of treatment processes using appropriate modern technology;

Overcome any defects in design, construction, operation and maintenance, in order to improve the capacity, quality and reliability of treatment plants;

Reduce pollution of the environment;

Enable energy efficient operation of raw and treated water pumping equipment;

Incorporate any other modifications in order to reduce the cost of production and increase the overall performance of treatment plants;

Rehabilitate and upgrade existing distribution systems.

River in Petaling Jaya, Selangor

2010-03-16T17:03:00.002+08:00

There are many river in Petaling Jaya. Most popular is River Klang (Sg. Klang). People also noted that there are two river which continuously undergo monitoring programme which are River Penchala (Sg. Penchala) and River Klang. Popular rivers in Petaling Jaya are:

Sg. Buloh
Sg. Damansara
Sg. Gasi
Sg. Kayu Ara
Sg. Kelang
Sg. Klang
Sg. Kuyoh
Sg. Penchala
Sg. Rumput
Sg. Tembul

"Save our reserve water"

Sludge Age

2010-02-20T20:04:00.005+08:00

Environmental Laws

2010-01-15T18:55:00.000+08:00

Source of Environmental Law

Legislation (federal, state, local)
Regulations (federal, state, local)
Court Desicions (interpreting statues and regulations)
Common Law
Constitutions (United States, state)
International Treaties
Foreign Regulations

Protection of Aquatic Life

2009-12-31T19:38:00.001+08:00

Anthropogenic stresses, introduction of chemicals into water, affect many species of aquatic flora and fauna.

Parts that concern to enviromentalis are

Dissolved oxygen (kill fish at low concentration)
Phosphates, ammonium and nitrate (cause significant changes in community strcuture)
Heavy metals and many synthetic chemical (ingested and absorbed by organisms cause bioaccumulated in body)
Pollutant (cause carcinogenic, reproductive and developmental effects)

Stress in River Basin

2009-12-31T19:30:00.000+08:00

1. Rapid urban development

2. Increase Pollution Loads - Sewage

3. Poor water quality

Effluent Characteristic From Sewage Treatment Plant

2009-12-04T09:31:00.001+08:00

The purpose of treating domestic wastewater in treatment plant is to ensure that discharging of effluent meet the requirement by authorities. Without authorities forces, people will easily dumping and pollute our environment.

Basic concept in Sewage effluent are less toxic/no toxic to living entity and separation of organic solid. Reaching of recycle and reuse of effluent may the ultimate achievement to wastewater treatmment operators.

Normally, sewage effluent water in Malaysia contain less metal and heavy metal if the incoming sewage stands individually. For the old network sewarage piping system, the infiltratin run-off interrupting the standard final effluent (FE). Most township in this country were very old, sewerage networking system have been infected by natural wear and tear. Recently, sewer rehabilition is the one of focussed item in sewerage operation.

Other kind of discharge such as illegal chemical dumping, waste from chicken slaugter house, food processing factory will also increase SS, BOD and COD in discharge effluent. There are encumbrance to operators where the authorities forcing had change method of treating incoming sewage. This occurance had increase operation cost of treatment plant especially electricity, labour cost and sludge management.

What ever it is, BOD max of 20mg/l, COD max of 50mg/l, SS mas of 50mg/l, not detectable O&G and ammonia level which less than 10 mg/l must be achieved to save Malaysian's reserve water. We save our environment, that means we execute our responsibility. God Bless Us.

Description of Devices

2009-11-25T07:44:00.001+08:00

Diffuser - To distribute bubble through provided porous space into wastewater. Bubble come from the blower/rotary blower. Most popular blower in Malaysia are Futsu, Taiko and Longtech. Normally, Longtech provides very nice/soft sound compare to other brand, however the brand source currently exhausted.

There are types of diffusers, for grit and aeration. For aeration, there will be a fine bubble diffusers type.

Blower - Provides air. Air supplied to wastewater trough piping and diffuser.

Surface aerator - Contain motor and blade sets. The blade set will circulate on surface of water. Splashing of water provides contact to ambient air. More kilowatts of motor normally will provides more contact between water and air.

Aeration Devices

2009-11-25T07:25:00.007+08:00

Diffusers Ejector

Rotary Blower/Compressor Surface Aerator

Aeration Tank

2009-11-05T17:35:00.000+08:00

Aeration tank is the major of the wastewater treatment structure. Treatment of wastewater using aeration equipment also called secondary treatment. Design of aeration tank absolutely refer to incoming load to the tank.

Aeration tank refers to several design for the activated sludge treatment type. A few secondary treatment tank are listed as below:

Extended aeration
Oxidation ditch
Batch reactor

For extended aeration tank, there are a few mutation where the process actually holding same concept such as:

Loyal extended aeration (LEA) - the word "loyal" refers to the designers or the manufacturer of the tank and the tank made from fibers.
Hi-Kleen - Normally known as a package plant where the whole structure from equilization tank, aeration tank and clarifier were ready made (fabricate in factory) from fiber or any suitable material.

The manufacturer are significantly using the same procedure in designing the treatment process, whereby the name normally to show to market about their company.

For batch reactor, few mutation of how the treatment stage are arrange prior completion of wastewater treatment process. Batch reactor means, a bulk/volume of wastewater be treated in the same tank. Batch reactor doesn't need clarifier during sedimentation stage. There are significant stage in the batch reactor includes:

Aeration stage
Settling/Sediment stage
Decanting/remove clean water stage

Best arrangement from the stage means reduction of expenditure during STP development/construction. On the other side, the operator will also need extra expertise in order to adapt this situation. The criticality scoring will increase as the situation will increase risk of releasing failed FE to the natural receivers. A few type of arrangement will also produce a few names such as:

IDEA - Intermittent Decanting Extended Aeration - become more popular in recent years.
IDEAL - Intermittent Decanting Extended Aerated Lagoon.
SBR - Sequencing Batch Reactor -most popular arragement in Malaysia because of the capabilty of existing designers and STP operator. (more easy than other 'batch' treatment process)

Malaysians Guidelines STP Developers

2009-10-23T11:28:00.003+08:00

PART 1

General Planning Approval Requirement

The application procedures for sewage treatment plant approval shall follow the requirement given in volume 2 of these guidelines. In general, the application for approval of a treatment plant shall include:

Sufficient land area for the sewage treatment plant plus additional area to allow for extension to the plant, where necessary.
Buffer zones
The location of the sewage treatment plant in relation to the reminder of the system. Sufficient topographic features shall be included to indicate its location in relation to stream and the point of discharge of treated effluent.
Schematic flow diagrams showing utility systems serving the plant processes and the flow through various plant units.
Piping, including any arrangements for by-passing individual units. The direction of flow through pipes shall also be shown.
Hydraulic profiles showing the flow of sewage, supernatant liquor, and sludge
Location, dimensions and elevations of all existing and proposed plant facilities
Point of discharge of treated effluent (effluent outfall) and the elevations of high and low water level of the body of water to which the plant effluent is to be discharged.
Type, size, features and operating capacity of all pumps, blowers, motors and other mechanical devices together with manufacturer catalogues.
Minimum, average and maximum flows, velocities and top water level in profiles.
Accessibility, landscaping and fencing
Flow measurement facilities
Materials, dimensions and specifications.
Ground conditions including levels, type, groundwater level and safe bearing pressure of foundation.
Details of foundation design.
All other component parts of the sewage treatment plant.
A technical report, which covers the ‘whole life’ cost evaluation of the plant.
Presentation requirements, process and instrumentation diagram, and mass balances.
Detailed drawings that are clear and legible and of standard format.
Detailed information on operation and maintenance

Accident Fire and Pollution?

2009-10-20T12:43:00.005+08:00

Looking at the smoke, you know what is happening to the environment.

This called an accidential pollution. Same like hazard spill at sea, factory or work place.

There is requirement for emergency requirement (ERP) in controlling such as hazards from above mention sources.

This accident happen during gun battle between drug dealers and police at Rio de Janeiro. Environment maybe doesn't like so critical to control such these accidential fire. But maybe, fine maybe increase to the dealer because of polluting.

ERP for accidential during gengstrism demolishment maybe needed in order to safe our environment.

Equilization Tank

2009-10-06T14:57:00.008+08:00

Tank which consist of transfer pump and aerator. Construction of equilization tank may useful to balance treatment intake in the aeration tank. It will also useful in contolling volume of water to be treated in the aeration tank. As such, equilization tank is very important in optimizing treatment process at downstream i.e if water in the aeration tank reach its volume, feed pump will stop feeding the aeration tank while the incoming water will simultaneously accumulated/be in equilization tank before next coming volume.

Like continuos treatment such as extended aeration (EA), Equilization tank will be a buffle tank for the aeration tank during surge flow. Surge flow in treatment process may cause stability of treatment process like 'over' flowing of MLSS which means, the depletion of suspended's food digestor.

Overflowing of digestor to FE will also cause unwanted bacteria (filamentous bacteria) to grow in treatment tank, hence create hard conditions during settlement process.

Guideline by Malaysian authority during wastewater plant construction shows that, construction of equilization tank will subsequently reduce aeration tank size by specific ratio.

Equipment Involve in Grease Trap/Tank

2009-09-30T08:13:00.006+08:00

As I said earlier, common grease tank located after grit tank. Saturated fat will be accumulated on top/surface of water. You will the accumulation in yellow color. The accumulation need to be removed to makesure optimization for downstream treatment process.

Removal equipment is called scum/oil/fat skimmer. Two type of scum skimmer normally seen in Sewage Treatment Plant (STP) which are pump/motor driven type and airlift driven type. The suction produce during its operation will skim out floating fat and drive the product to drying bed or dewatering unit before it can be dumped outside. Picture of equipment were as below:

Motor driven scum skimmer

Airlift driven scum skimmer

Problem may appear with these equipment are bloockage due to improper rugs (normally plastic and diapers/pad) screening at earlier stage and broken of suction pipe and etc.

Equipment in Grit Trap (Tank)

2009-09-11T13:06:00.006+08:00

Normally, grit tank will be equipped with grit pump, to remove bottom's settled grit. For a big construction of sewage water treatment, the removal equipment may use airlift system to remove bottom product. Airlift system is a principal system that involve pressure gradient in a pipe. The design of airlift were illustrated as below: