What is formed when a coagulant reacts with finely divided and suspended material in raw water?

When a coagulant is added to raw water, it reacts with the finely divided and suspended particles present in the water. This reaction leads to the formation of floc, which consists of larger, aggregated particles that coalesce together. The process of coagulation helps to remove unwanted contaminants by clumping them into larger masses that can be more easily removed from the water during subsequent treatment processes such as sedimentation and filtration.

Floc is essential in water treatment because it aids in improving the clarity of the water and reducing turbidity. Once the floc is formed, it can settle out of the water or be trapped in filter media, thus helping to provide cleaner water for potable use or other applications. In contrast, sludge is typically the sediment that accumulates at the bottom of sedimentation tanks after floc has settled out, while scum and residue refer to other specific byproducts that arise from processes different from flocculation.