What is the main purpose of using a coagulant in water treatment?

The main purpose of using a coagulant in water treatment is to clarify water by agglomerating particles. Coagulants, such as aluminum sulfate or ferric chloride, are added to water to promote the aggregation of fine suspended particles and colloidal matter. When these chemicals are introduced, they neutralize the charges on the particles, allowing them to stick together and form larger clumps, known as flocs. This aggregation process makes it easier to remove these particles from the water during subsequent filtration and sedimentation processes, resulting in clearer water.

This mechanism is crucial in water treatment processes because it significantly improves water quality by removing impurities that could otherwise impart undesirable characteristics or pose health risks. While enhancements to flavor, disinfection, and reducing sedimentation time are important aspects of water treatment, they are not the primary function of coagulants. The pivotal role of coagulants is focused on clarifying the water effectively, making this the correct choice.