In wastewater treatment, what is the role of a coagulant?

In wastewater treatment, a coagulant plays a crucial role in the removal of suspended particles from the water. The primary function of a coagulant is to destabilize colloidal particles, which are often too small to settle out of the liquid by gravitational forces alone. When a coagulant is added to the wastewater, it neutralizes the charges on these particles, enabling them to clump together.

This process, known as coagulation, results in the formation of larger aggregates called flocs. Once these flocs are formed, they can be more easily separated from the liquid during subsequent processes, such as sedimentation or filtration. Thus, the addition of a coagulant is essential for improving the overall efficiency of the treatment process by facilitating the removal of troublesome suspended solids, improving water clarity, and reducing the concentration of pollutants.

The other options relate to different aspects of water treatment but do not encapsulate the specific function of coagulants. While some processes may involve separation of solids from liquids or disinfection, these do not directly define the role of coagulants in enhancing the specific removal of suspended particles in wastewater.