Water treatment

Water treatment refers to the process of improving the quality of water to make it suitable for a specific end-use. The end-use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation, or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use.

Process

The water treatment process involves several stages, each designed to remove or reduce specific contaminants. The stages include:

• Coagulation and Flocculation: This is the first step in the water treatment process where liquid aluminum sulfate (alum) and/or polymer is added to untreated (raw) water. The purpose is to create larger particles from the small, unstable particles present in the supply water.

• Sedimentation: The water then moves into sedimentation basins where the heavy floc particles settle to the bottom. The settled particles are known as sludge, which is then removed and treated.

• Filtration: The water is then filtered through layers of fine, granulated materials — either sand, or sand and coal, depending on the treatment plant. This process removes the remaining suspended particles and unsettled floc in addition to many microorganisms and algae.

• Disinfection: After filtration, chlorine or other disinfectant is added to kill any remaining bacteria, viruses, or parasites and to protect the water from germs when it is piped to homes and businesses.

Types of Water Treatment

There are several types of water treatment, including:

• Physical Water Treatment: This involves the use of physical processes to treat water, such as filtration, sedimentation, distillation, and others.

• Chemical Water Treatment: This involves the use of chemical processes to treat water, such as chlorination, ozonation, and others.

• Biological Water Treatment: This involves the use of biological processes to treat water, such as activated sludge, trickling filters, and others.

Importance

Water treatment is crucial for ensuring the safety and quality of water. It helps to remove harmful substances from water, making it safe for consumption and use. It also helps to prevent the spread of waterborne diseases.