Name one common coagulant used in water treatment processes.

Aluminum sulfate is a widely used coagulant in water treatment processes because of its effectiveness in promoting the aggregation of particles suspended in water, which is essential for the clarification process. When added to raw water, aluminum sulfate hydrolyzes to form aluminum hydroxide, which has a strong affinity for binding with colloidal particles, microorganisms, and other impurities. This reaction leads to the formation of larger agglomerates, or flocs, that can then be removed from the water by sedimentation or filtration.

This process is crucial in the treatment of drinking water as it helps improve water quality by reducing turbidity and removing contaminants that can affect taste, odor, and safety. Additionally, aluminum sulfate is cost-effective and widely available, making it a practical choice for many water treatment facilities.