In water treatment, what is the primary purpose of sedimentation?

The primary purpose of sedimentation in water treatment is to allow heavier particles to settle out of the water. This process relies on gravity, as contaminants such as silt, sand, and larger solids are removed from the water by allowing them to naturally sink to the bottom of a treatment basin. Sedimentation is an essential step in the treatment process because it effectively reduces the turbidity of water, making it clearer and less dirty. By removing these heavier particles, the remaining water can then undergo further treatment processes, such as filtration and disinfection, more effectively.

The other options are related to water treatment but serve different functions. For instance, filtering contaminants involves passing water through a barrier that captures smaller particles and impurities, while disinfection focuses on eliminating pathogens from the water. Aeration is the process of introducing air into the water, which can help remove certain gases and increase oxygen levels, but it is not the primary aim of sedimentation. Each of these processes contributes to the overall quality of treated water, but sedimentation specifically targets the removal of heavier solids through settling.