What is flocculation?

Flocculation is a key process used in water treatment to enhance the removal of suspended solids from water. The correct definition involves gentle mixing of water to promote the growth of floc, which are aggregates of particles that clump together. This process allows small particles to merge and form larger clusters that can settle out more easily during subsequent sedimentation steps.

During flocculation, chemicals called coagulants are typically added to help destabilize colloidal particles suspended in the water. Once these particles are destabilized, gentle mixing encourages them to collide and stick together, forming larger aggregates or floc. The gentle mixing is crucial; if the mixing were too vigorous, it might break apart the floc rather than promote its growth.

In contrast, other choices refer to different stages or aspects of water treatment. Rapid mixing refers to an initial step that enables coagulant distribution, but it does not foster floc growth. Measuring turbidity involves assessing the clarity of water and is more focused on diagnosing water quality rather than a treatment process. Filtration is a subsequent step where the floc and any remaining suspended particles are removed from the water, but it is not the same as flocculation itself. Thus, the gentle mixing to enhance floc growth is