Water Treatment Plant (WTP)

A water treatment plant is a destination where wastewater (water that is no longer fit for its current purpose) moves to once it leaves homes and businesses through sewage pipes. The sewage system contains miles of pipes below ground where wastewater flows to the treatment plant for processing.

Water treatment plants typically receive water from various sources such as rivers, lakes, reservoirs, or groundwater. The water goes through a series of treatment processes to remove physical, chemical, and biological contaminants. The specific treatment methods employed may vary depending on the quality of the source water and the intended use of the treated water.

The Benefits of WTP

Water Treatment Plants (WTPs) are used by all leading industries and households to treat their water. All the leading pharmaceutical, food & beverage chemical, textile, and other industries use WTP to purify water and remove any non-toxic or toxic materials or chemicals from it.

1. To clean industry effluent and recycle it for further use
2. To reduce the usage of fresh water in industries
3. To preserve the natural environment against pollution
4. To meet the standards for the emission of pollutants set by the Government and avoid heavy penalty
5. To reduce expenditure on water acquisition

Types of Water Treatment Plant

There are several types of water treatment plants, each designed to address specific water treatment needs. Here are some common types:

1. Iron Removal Plant: An Iron Removal Plant (IRP), also known as an Iron Removal System or Iron Filter, is a water treatment system designed to remove iron and other impurities from water. Iron is a common contaminant found in water sources, especially groundwater, and it can cause various issues such as metallic taste, staining of fixtures and laundry, and clogging of pipes and appliances.
An IRP typically consists of one or more filtration units that utilize various methods to remove iron from water. The most common types of filters used in iron removal plants include:

Media Filters: These filters contain a bed of filtration media such as manganese dioxide, green sand, or anthracite coal. As water passes through the filter bed, iron particles are trapped and removed.
Oxidizing Filters: These filters use an oxidizing agent, such as chlorine or potassium permanganate, to convert dissolved ferrous iron (Fe2+) into ferric iron (Fe3+). The ferric iron then precipitates out and can be filtered or settled.
Catalytic Filters: These filters use a catalytic medium, such as catalytic carbon or firm, which facilitates the oxidation of ferrous iron to ferric iron. The resulting precipitates are then filtered out.
Ion Exchange Filters: These filters use a resin bed that exchanges iron ions for sodium or potassium ions. As water flows through the resin bed, iron ions are captured and replaced by sodium or potassium ions.

2. Reverse Osmosis (RO) Plant:
A reverse osmosis (RO) plant is a water treatment system that uses a process called reverse osmosis to purify water. Reverse osmosis is a technology that involves the application of pressure to force water molecules through a semipermeable membrane, removing impurities, contaminants, and dissolved solids in the process.

The reverse osmosis plant consists of several key components:

Intake: This is the point where raw water is collected, typically from a natural source such as a river, lake, or underground well.
Pre-treatment: Before entering the reverse osmosis process, the water undergoes pre-treatment to remove large particles, sediments, and other impurities. This step usually involves processes such as sedimentation, filtration, and chemical dosing.
High-pressure pump: The pre-treated water is then pressurized using a high-pressure pump. The purpose of this pump is to overcome the natural osmotic pressure and push water through the semipermeable membrane.
Reverse osmosis membranes: These are the heart of the RO plant. The pressurized water is forced through a series of semipermeable membranes that allow only water molecules to pass through while rejecting dissolved salts, minerals, contaminants, and other impurities.
Product water storage: The purified water, known as product water or permeate, is collected and stored in a clean water tank for later use.
Concentrate disposal: Alongside the purified water, a portion of the feed water that does not pass through the membranes, known as the concentrate or reject stream, is discharged. The concentrate contains the concentrated impurities and salts removed during the process.
Post-treatment: The product water may undergo further treatment to adjust its pH, remineralize it, and disinfect it before it is considered suitable for consumption or specific applications.

Reverse osmosis plants are widely used in various industries and applications, including municipal water supply, desalination of seawater, production of ultra-pure water for industrial processes, and residential water purification systems. They are highly efficient in removing contaminants and producing high-quality purified water.

3. Softener Plant:
A softener plant, also known as a water softener plant or water softening system, is a facility or system designed to remove hardness minerals from water. Hardness in water is primarily caused by the presence of calcium and magnesium ions, which can lead to various issues such as scaling, reduced lathering of soaps, and the formation of deposits in pipes and appliances.
A softener plant typically consists of one or more water softeners, which are devices that use a process called ion exchange to remove the hardness minerals from water. The most common type of water softener is a cation exchange resin bed, where the resin beads attract and remove the calcium and magnesium ions in exchange for sodium ions.
The water-softening process…

After a period of time, the resin beads in a water softener get coated with hard minerals and need to be cleaned. The cleaning process is called “recharge”. Recharging consists of five stages: Fill, Brining, Brine Rinse, Backwash and Fast Rinse.

Note: The times for each of these stages during recharge are variable and change just about every time the water softener regenerates based on how much water was used and what the system forecasts for water needs going forward.

Fill: Salt dissolved in water is called brine. Brine is needed to clean the hard minerals from the resin beads. To make the brine, water flows into the salt storage area during the fill stage. The time this takes can vary from a few minutes to maybe 20 minutes.
Brining: During brining, brine travels from the salt storage area up into the resin tank. Brine is the cleaning agent needed to remove hard minerals from the resin beads. The hard minerals and brine are discharged into the drain. The time this takes can vary from 30 minutes to maybe 100 minutes.
The nozzle and venturi create a suction to move the brine, maintaining a very slow rate to get the best resin cleaning with the least amount of salt.
Brine Rinse: After a pre-measured amount of brine is used, the brine valve closes. Water then continues to flow in the same path as during brining, except without the brine. This flushes hard minerals and brine from the resin tank into the drain.
Backwash: During backwash, water flows up through the resin tank at a fast flow rate. This flushes out any accumulated iron, dirt and sediment from the resin bed and into the drain. The time this takes can vary but is generally 3 to 10 minutes.
Fast Rinse: Backwash is followed by a fast flow of water down through the resin tank. The fast flow flushes brine from the bottom of the tank. It also serves to pack in the resin beads. The water softener system returns to water softening service after fast rinse. The time this takes can vary but is generally 3 to 10 minutes.

4. Ultrafiltration Plant for Pharmaceuticals:
An ultrafiltration plant is a type of water treatment system that utilizes the process of ultrafiltration to remove suspended solids, bacteria, viruses, and other impurities from water. Ultrafiltration (UF) is a membrane filtration process that operates on a molecular level to separate particles based on their size.

In an ultrafiltration plant, water is passed through a series of hollow fiber membranes that have very fine pores. These membranes act as a physical barrier, allowing water and dissolved substances to pass through while capturing and retaining particles and contaminants larger than the pore size. The pore size of ultrafiltration membranes typically ranges from 0.01 to 0.1 micrometers, effectively removing suspended solids, colloids, bacteria, and some viruses.

5. Demineralized Plant (DM Plant):
A DM plant, also known as a demineralization plant, is a water treatment system used to remove dissolved impurities and minerals from water. The primary purpose of a DM plant is to produce demineralized water, which is essentially free from mineral salts and other impurities.
Demineralized water finds application in various industries where high-purity water is required, such as power plants, pharmaceuticals, electronics manufacturing, and boiler-feed water systems. Some common impurities removed by a DM plant include calcium, magnesium, sodium, chloride, sulfate, and silica.
The DM plant typically consists of several components and processes to achieve the desired water quality.

The key components include:
Pre-treatment: This stage involves the removal of suspended solids, organic matter, and larger impurities through processes like filtration, clarification, and sedimentation.
Cation Exchange Unit: In this step, the water passes through a cation exchange resin bed, which replaces positively charged ions (such as calcium, magnesium, and sodium) with hydrogen ions.
Anion Exchange Unit: The water then moves through an anion exchange resin bed, where negatively charged ions (such as chloride, sulfate, and bicarbonate) are exchanged for hydroxide ions.
Mixed Bed Unit: In this stage, a mixture of cation and anion exchange resins is used to further remove any remaining impurities and achieve a high level of demineralization.
Polishing: This optional step involves additional treatment processes like activated carbon filtration or ultraviolet (UV) disinfection to enhance the water quality and remove any residual impurities.

By going through these processes, a DM plant can produce demineralized water with extremely low levels of dissolved solids, resulting in high-purity water suitable for various industrial applications.

Process of Water Treatment Plant:
The processes involved in water treatment plants can include the following:

Coagulation and Flocculation: Chemicals are added to the water to destabilize suspended particles, which then form larger particles called flocs.
Sedimentation: The water is allowed to settle, and the flocs gradually settle to the bottom of the sedimentation tanks, forming sludge.
Filtration: The water passes through various filters such as sand filters, activated carbon filters, or membrane filters to remove smaller particles, dissolved substances, and microorganisms.
Disinfection: To kill or inactivate harmful microorganisms, disinfectants like chlorine, chloramine, or ultraviolet (UV) light are applied to the water.
pH Adjustment: The pH level of the water may be adjusted using chemicals to meet specific standards.
Additional Treatment: Depending on the quality of the source water and specific requirements, additional processes like advanced oxidation, ion exchange, or reverse osmosis may be employed.

Once the water has been treated, it is typically distributed through a network of pipes to homes, businesses, industries, and other users. The treated wastewater generated during the process is usually further treated to remove pollutants before it is discharged back into the environment, such as rivers or oceans.

Water treatment plants play a crucial role in safeguarding public health by ensuring a reliable supply of clean and safe drinking water, as well as protecting the environment by treating and returning wastewater in a responsible manner.

Sintech Engineering Solutions is an Importer and manufacturer of Water Treatment Plant (WTP) in Bangladesh.

Email: sales@sintechbd.com; Cell: 01829-675191