What is commonly the next step after sedimentation in the water treatment process?

After sedimentation in the water treatment process, the next common step is filtration. Sedimentation allows for the settling of larger particles and flocs that have been formed during earlier processes like coagulation and flocculation. Once this process is completed, the remaining water, which may still contain smaller particles and impurities, undergoes filtration to remove these residual contaminants.

Filtration involves passing the water through various media, such as sand, gravel, or specialized membranes, which effectively capture and retain remaining suspended solids, bacteria, and other impurities. This step is crucial for ensuring that the water is clean and safe for consumption or discharge.

Coagulation and flocculation are typically performed before sedimentation. Coagulation introduces chemicals that destabilize particles, while flocculation involves gentle mixing to promote the formation of larger aggregates. Chlorination, on the other hand, is a disinfection step that usually follows filtration and is used to kill remaining pathogens. Thus, filtration serves as an essential transitional process that precedes further treatment and disinfection.