What is a coagulant in water treatment?

A coagulant plays a crucial role in water treatment by facilitating the removal of suspended particles from water. The primary function of a coagulant is to aggregate fine particles into larger clusters known as flocs. This process makes it significantly easier to separate these aggregates from the water during subsequent treatment steps, such as sedimentation or filtration.

When coagulants are added to water, they neutralize the charges on suspended particles, which typically repel each other due to similar electrical charges. Once neutralized, these particles can bond together, forming larger aggregates that are heavy enough to settle out of the water or be captured in filters. Effective coagulation enhances water clarity and improves the efficiency of treatment processes by reducing turbidity and the concentration of contaminants.

This concept is distinct from the other options, as the function of a coagulant specifically pertains to the removal of suspended solids and not the addition of nutrients or the action of filters. Understanding the role of coagulants is essential for water treatment operators to ensure water quality and compliance with health standards.