What is the role of filtration in the conventional surface water treatment process?

Filtration plays a crucial role in the conventional surface water treatment process by effectively removing remaining particles and pathogens from the water. This step follows various preliminary treatment processes such as coagulation and sedimentation, which help to aggregate and settle larger particles. During filtration, water passes through filter media—such as sand, gravel, or membranes—that trap these smaller suspended solids and microorganisms, including bacteria and protozoa.

The filtration process is essential for ensuring that the treated water meets public health standards for safety and clarity. By capturing these contaminants, filtration helps to produce clean, safe drinking water, minimizing the risk of waterborne diseases. Additionally, while filtration can improve water quality by reducing turbidity and removing pathogens, it does not intentionally increase turbidity, add chemicals, or cause chemical reactions, which are roles associated with other steps in the treatment process.