What is the function of chemical coagulants in wastewater treatment?

The function of chemical coagulants in wastewater treatment is primarily to aggregate fine particles into larger clumps for easier removal. This process, known as coagulation, involves the addition of specific chemicals that destabilize the colloidal particles in the water. As these particles aggregate, they form larger flocs, which can then be more easily separated from the liquid during subsequent processes like sedimentation or filtration.

This aggregation is crucial because fine particles are often abundant in wastewater and can be very difficult to remove through physical means alone. By promoting the formation of larger aggregates, chemical coagulants effectively enhance the efficiency of the treatment process, resulting in clearer effluent and improved overall water quality.

In the context of wastewater treatment, the primary role of coagulants is not to disinfect the water, stabilize sludge, or enhance nutrient removal directly, making it clear why the focus is on their ability to facilitate the aggregation of particles.