Water Treatment Plant

Water treatment Plant at Beladin and Maludam

There are two treatment plants at the building which is an old system and new system treatment. The raw water intake taken from surface water that having highest of color and smell but lowest of turbidity. Two treatment plants working in 24 hours per day. The old treatment system can treat only 31288 liter per Hour (LPH) lower than a new treatment system that enclosure 70,000 m³ per hour. Water treatment plant at Maludam, the raw water pumped (flow rate) in 100,000 m³ per hour.

Screening

Screening is the first element in a treatment plant to allow processing of raw water. The purposes of screening are used to remove wood chips, leaves, aquatic plants and floating impurities and prevent damage of the pump. Actually, to protect the structure downstream against large objects which could create obstructions in some of the facility’s units. It’s easily separate and remove large matter carried along by the raw water, which might negatively affect the efficiency of later treatment procedures. Screening is carried out by a manually cleaned bar screen at the Kampung Beladin treatment plant and also camping Maludam. Based on the Waterwork section, the efficiency of the screening operation depends on the spacing between screen bars:

1. Fine screening: spacing< 10 mm
2. Medium screening: 10mm < spacing <  40 mm
3. Coarse screening: 40mm > spacing

Raw water has many types of impurities such as floating and large suspended solids like paper, rags, plastics and grits. Also, dissolved solid in organics and inorganics, dissolved gases such as hydrogen sulphide, methane and microorganisms such as pathogens, bacteria and viruses. The figure 3.2 shows the example of screening Beladin water treatment plant.

Screening process

  

Chemical Diffusion

The main purpose of chemical diffusion is to produce fineness FLOCS that settle and separated from the water called coagulant processing. Mostly, chemical diffusion is able to remove color, odor and taste of water.

Actually, raw water contains a lot of impurities but in colloid form. Colloid is composed of a mass of clay and organic materials of art. It is not easy to settle under the force of gravity and cannot be separated from the water simply filtered in the usual way.

When chemical diffusion is done by applying certain types of chemicals, called coagulants (Coagulants) in water, the most commonly used are Alum, ACH and Sodium Aluminate. When a coagulant added to water and mixed average it produces a thick, sticky dross and trap suspended material in the water when they settle down to the bottom of the tank. Sediment is able to separate the sticky mass of colloidal quickly. Figure 3.3 illustrate the mixing of chemical dosages and coagulant process. Chemicals that are often used for thickening;

Aluminium (Aluminium Chlorohydrate, ACH),  Soda Ash, Polymer

Coagulant process (mixing of chemical)

                

3.3.6.3 Flocculation

Flocculation is a physical and chemical process which is used for the removal of the visible sediments and material from water which makes it a colloidal solution. It can be done through agitation or by adding flocculating agents.

This process is used when the small-suspended solids having low specific gravity and low settling velocity cannot be separated by sedimentation easily. In wastewater treatment, this usually occurs particularly with particles of less than 50 µm in size. When high concentrations of flocculent particles are present, the creation of velocity gradients in the suspension causes collisions between particles with consequent agglomeration. This natural flocculation process can be enhanced by the application of controlled velocity gradients through hydraulic turbulence or mechanical stirring.  The number of collisions in a suspension is proportional to the velocity gradient.

In the flocculation process, the polymers are used as flocculating agent for the formation of bridges between the flocs such as clumps of bacteria and impurities which form a cluster after using ACH and Soda Ash. These agents (Polymers) get adsorbed on the particles by reacting with positively charged suspension. It is very essential to gently mix the flocculating agent at a slow speed so that small flocs can easily agglomerate into large particles.

Flocculation process

Sediment tank

Sedimentation is basic concept at water treatment plants. Clarification is similar term, which usually refers specifically to the function of sedimentation tank in removing suspended matter form the water to give a clarified effluent. In this water treatment, Sedimentation is commonly used to remove impurities that have been done by coagulation and flocculation process called 'flocs'. Naturally, Sediment tank used earth gravity to settle rapidly all the largest flocs. Besides that, the settlement of flocs called slugde and removed by using backwash process.

Sediment tank (sediment flocs process)

         

 Backwash process

To keep water treatment filters functional, they have to be cleaned periodically to remove particulates. Backwashing is pumping water backwards through the filter media, sometimes including intermittent use of compressed air (blower) during the process. Backwashing is used to preventive maintenance, while the filter media can be reused. The system of backwashing used automated process at Beladin treatment plant (package 2) and package 2 is used manually also at Maludam treatment plant.

Filters should be washed and cleaned from all dirt caught during filtration process. The filtration will be cleans once per days after 24 hours water treatment plants operation. The backwash was taken 30 minutes to wash the filters. Before treatment, the valve should be closed at the filtration and the valve of high level tank backwashing will be opened. Figure 3.6 shows the storage of backwash high level tank at Beladin water treatment plant.

 Backwash water storage

Filtration

The purpose of fitration is to removes suspended particles from water such as turbidity and colloidal material that still remaining after settlement tank process. Actually, some types of bacteria, taste and odor also can removed through filtration because reaction occurs when water passes through the filter. In the filter, up to 99.5% of the suspended solids in the water can be removed, including minerals, floc and microorganisms.

Filtration have 3 types which is slow sand filter, rapid gravity filters and vertical and horizontal pressure filters. Maludam and Beladin water treatment plants was used rapid gravity filters. The filtration is now required for water treatment systems. Filter must reduce turbidity to less than 0.5 NTU. The filtration area at Maludam and Beladin water treatment plant.

Filtration process area

            

       

Filtering process have a several layers of sand and gravel size, while all the impurities that remaining in water will be retained by layers of sand.

Disinfection

Water should be disinfected before it enters the distribution system to ensure that any disease-causing bacteria, viruses, and parasites are destroyed. Chlorine is used because it is very effective disinfectant, and residual concentrations can be maintained to guard against possible biological contamination in the water distribution system. The primary goal of water treatment is to ensure that the water is safe to drink and does not contain any disease-causing microorganisms.

 Disinfection (Chlorine and Soda Ash)

 pH correction

Lime is added to the filtered water to adjust the pH and stabilise the naturally soft water in order to minimise corrosion in the distribution system, and within customers’ plumbing.

Water resources

Introduction

On the previous report, Malaysia has received rainfall of 324 billion m³/year in year 2000. It distributed surface runoff and evapo-transpiration about 152 billion m³/year, respectively and only 20 billion m³/year becomes groundwater. Malaysia‘s water status are diverse, increase and competing needs. However the future forecast indicated that water supply demand cannot be met in many locations due to uneven rainfall distribution, temporarily or spatially, degradation in the raw water supply catchments, because of a-control opening of forested areas (logging, roads, urbanizations) resulting in massive sedimentation flow into rivers, pollution in rivers as it passes urban areas, reaches between raw water source catchment/storages and downstream water supply intake.

Water quality is most important to preventing and protect humans from disease. However, water treatment at the plant should treated before contributing to the consumers. Water quality must be according to the specification of water drinking with the Nation Standard for Drinking Water Quality. Actually, raw water resource has a differences classification such as turbidity, chemical content, color and pH. The treatment process at treatment plants have various types that considered of raw water respectively. There are three water quality parameters are physical parameter, chemical parameter and biological parameter.

Water recycles processes 

Stages of the cycle are:

1)      Evaporation

2)      Transportation

3)      Precipitation

4)      Groundwater

5)      Run-off

Water cycle process

 Evaporation

Water is transferred from the surface to the atmosphere through evaporation, the process by which water changes from a liquid to a gas. The sun's heat provides energy to evaporate water from the earth’s surface. Land, lakes, rivers and oceans send up a steady stream of water vapor and plants also lose water to the air (transpiration).

 Transportation

Transportation means the movement of water through the atmosphere, specifically from over the oceans to over land. Some of the earth’s moisture transport is visible as clouds, which themselves consist of ice crystals and/or tiny water droplets.

Clouds are propelled from one place to another by either the jet stream, surface-based circulations like land and sea breezes or other mechanisms. Most water is transported in the form of water vapor, which is actually the third most abundant gas in the atmosphere. Water vapor may be invisible to us, but not to satellites which are capable of collecting data about moisture patterns in the atmosphere.

 Condensation

The transported water vapor eventually condenses, forming tiny droplets in clouds.

 Precipitation

The primary mechanism for transporting water from the atmosphere to the surface of the earth is precipitation.

When the clouds meet cool air over land, precipitation, in the form of rain, sleet or snow, is triggered and water returns to the land or sea. A proportion of atmospheric precipitation evaporates.

 Groundwater

Some of the precipitation soaks into the ground and this is the main source of the formation of the waters found on land - rivers, lakes, groundwater and glaciers.

Some of the underground water is trapped between rock or clay layers - this is called groundwater. Water that infiltrates the soil flows downward until it encounters impermeable rock and then travels laterally. The locations where water moves laterally are called ‘aquifers’. Groundwater returns to the surface through these aquifers, which empty into lakes, rivers and the oceans.

Run-Off

Most of the water, which returns to land flows downhill as run-off. Some of it penetrates and charges groundwater while the rest, as river flow, returns to the oceans where it evaporates. As the amount of groundwater increases or decreases, the water table rises or falls accordingly. When the entire area below the ground is saturated, flooding occurs because all subsequent precipitation is forced to remain on the surface.

Different surfaces hold different amounts of water and absorb water at different rates. As a surface becomes less permeable, an increasing amount of water remains on the surface, creating a greater potential for flooding. Flooding is very common during winter and early spring because frozen ground has no permeability, causing most rainwater and melt water to become run-off.

Water Source

Sources of water in treatment plants have a differences source which is groundwater, seawater and surface water. However, the difference source has a difference of characteristic in term chemical parameter, physical parameter and microbiological as shown in table 3.1.

Groundwater	Surface water
Ø  Constant composition Ø  High mineral content Ø  Low turbidity Ø  Low colour Ø  Low or no dissolved oxygen (D.O). Ø  May have CO₂, H₂S. Ø  High hardness Ø  High Fe and Mn	Ø  Variable composition Ø  Low mineral content Ø  High turbidity Ø  Colored Ø  D.O present Ø  Low hardness Ø  Taste and odor Ø  Clay and silt

Table 3.1 Chemical, physical and microbiological parameter

Water Treatment Plant

3.3.1 Water treatment Processes (Plant)

Water is very important in our daily lives in every human being and the environment. Therefore, the water treatment systems are required to achieve their drinking water quality standard and supplying water to consume. Water treatment is based on the standards set by the World Health Organization (WHO) for the raw water or potable water (Standard drinking water).

3.3.2 General Introduction

Typically, the water supply system in the district has major components that encompass the entire department a day trip. These components are Water Production System (production rate), Water Distribution System, Quality Control System and Water Revenue Collection System.

3.3.3 Water Supply objective

To supply adequate drinking water for all users and water quality in accordance with a predetermined standard.

3.3.4 Water Requirements

Water requirements divided into three (3) types such as domestic needs, industrial or commercial and water loss.

Water Treatment process

Definition

3.3.5.1 Raw water

Water pumped from the source which is to be treated. The raw water must be pumped to the water treatment plant to treat and take from the catchment.

3.3.5.2 Fleece Blanket/Floc Formation

A layer of fine silt suspended in the clarifier which acts as a blanket to trap other silt materials in the incoming raw water.

3.3.5.3 Desludging

The process of removing excess flows/sediment from the sedimentation tank.

3.3.5.4 Backwashing

A process for cleaning filter media with clean water.

3.3.5.5 Clear Water Well

Storage tank which receives the water after the filtration process.

3.3.5.6 Storage tank

A storage tank for treating water, usually located on an elevated platform.

3.3.5.7 Clarifier

A tank structure whereby the fleece blanket is allowed to form. A compartment to separate out the finer fleece particles from the water which passes through the filter media.

3.3.5.8 PH

A measurement of acidity and alkalinity of the raw water and clear water. The range of clear water should be 6 to 7 of pH by followed of the National Standard water drinking.  

3.3.5.9 Color

The color of the water as determined at the time of analysis. Color should be white or clear.

3.3.5.10 Residual Aluminum

The amount of aluminum left in the water after the reaction with other foreign materials present in the same water.

3.3.5.11 Fluoride residual

The amount of fluoride left in the water after the reaction with other foreign materials present in the same water. 

Environment Quality Act, 1974

What kind of regulation can do???

Environmental Quality Act, 1974

Malaysia has had environmentally-related legislation since the early 1920s (table 4). But the legislation is limited in scope and inadequate for handling complex emerging environmental problems. So through EQA, 1974, a more comprehensive form of legislation and an agency to control pollution was established.

EQA is an enabling piece of legislation for preventing, abating and controlling pollution, and enhancing the environment, or for other related purposes. Pollution, as declared in EQA, includes the direct or indirect alteration of any quality of the environment or any part of it by means of a positive act or act of omission.

Pollution is ‘controlled’ through the mechanism of licences issued by the Department of Environment. The mode of control is by prescribing, by means of a ministerial regulation, that licences are mandatory for:

• The use and occupation of prescribed premises;
• Discharging or emitting wastes exceeding acceptable conditions into the atmosphere, as well as noise pollution, polluting or causing the pollution of any soil or surface of any land;
• Emitting, discharging or depositing any wastes or oil, in excess of acceptable conditions, into inland waters or Malaysian waters.

The provision of "acceptable conditions" is controversial because the polluter is not liable for prosecution if the discharge are within those acceptable conditions, even if the effluents are sufficient to severely damage the environment. Most people adversely affected by pollution do not want to seek legal remedy through common law because of the prolonged nature of such hearings and the costs incurred.

Currently, 16 sets of regulations and orders are enforced by the Department of Environment under EQA. Despite government efforts to implement environmental laws and regulations, it has been found that enforcement measures need to be further enhanced to ensure the full compliance with laws and regulations.

With regard to monitoring and enforcement, surveillance capability will be strengthened. The penalty structure related to environment offences will be revised to ensure a more effective deterrent, especially in the case of repeat offenders. The enforcement function of agencies such as the Department of Environment, Health Department, Pesticide Board and local authorities will be rationalized and streamlined, and adequate training will be provided for their enforcement staff.

Environmental laws and regulations One of the three strategies embodied in EQA, 1974, is for the regulation of pollution. The other two strategies are for preventing and abating any form of pollution. To bring the law and other environmentally-related laws into effect, the laws and regulations listed below have been introduced and are strictly enforced by the Department of Environment.

(i)Control of agro-based water pollution

• Environmental Quality (Licensing) Regulations, 1977
• Environmental Quality (Prescribed Premises) (Crude Palm Oil) Order, 1977
• Environmental Quality (Prescribed Premises) (Crude Palm Oil) Regulations, 1977, and (Amendment) 1982
• Environmental Quality (Prescribed Premises) (Raw Natural Rubber) Order, 1978
• Environmental Quality (Prescribed Premises) (Raw Natural Rubber) Regulations, 1978

(ii)Control of municipal and industrial waste water pollution

• Environmental Quality (Sewage and Industrial Effluents) Regulations, 1979
• Environmental Quality (Prohibition on the Use of Controlled Substance in Soap, Synthetic Detergent and Other Cleaning Agents) Order, 1995

(iii) Control of industrial emissions

• Environmental Quality (Clean Air) Regulations, 1978
• Environmental Quality (Compounding of Offenses) Rules, 1978

(iv)Control of motor vehicle emissions

• Motor Vehicles (Control of Smoke and Gas Emission) Rules, 1977 (made under the Road Traffic Ordinance of 1958)
• Environmental Quality (Control of Lead Concentration in Motor Gasoline) Regulations, 1985
• Environmental Quality (Motor Vehicle Noise) Regulations, 1987

(v)Control of toxic and hazardous waste management

• Environmental Quality (Scheduled Wastes) Regulations, 1989
• Environmental Quality (Prescribed Premises) (Scheduled Wastes Treatment and Disposal Facilities) Order, 1989
• Environmental Quality (Prescribed Premises) (Scheduled Wastes Treatment and Disposal Facilities) Regulations, 1989
• Promotion of Investments (Promoted Activities and Products) (Amendment) (No. 10) Order, 1990 (made under the Promotion of Investments Act, 1986)