In a conventional filtration system, what process is referred to as fast mixing?

In a conventional filtration system, fast mixing is specifically associated with the coagulation process. This stage involves the rapid mixing of chemicals, usually coagulants, with raw water to destabilize the particles and promote aggregate formation.

During this process, the high energy mixing ensures that the coagulants are evenly distributed throughout the water, which helps to neutralize charges on suspended particles and promotes their agglomeration into larger particles, known as flocs, during subsequent flocculation. Fast mixing is crucial because it sets the stage for effective coagulation, leading to more efficient removal of suspended solids in the later stages of treatment.

In contrast, options such as filtration, clarification, and flocculation follow different purposes in the water treatment process. Filtration involves passing water through a medium to remove remaining particles, while clarification involves allowing solids to settle out of water. Flocculation, while related to the aggregation of particles, occurs after fast mixing and involves slower mixing to encourage the clumping of the destabilized particles formed during coagulation. Thus, the selection of coagulation is correct in linking fast mixing with its function in a conventional filtration system.