Sedimentation of solid matter occurs during which step of water treatment?
Water treatment has six steps involved in it: Aeration, coagulation, clariflocculation, filtration, chlorination, storage. Coagulation is one of the steps of the water treatment process which allows sedimentation of solid matter present in water. Alum is added for this. When alum is added the pH value of water decreases. Therefore, lime is added to the water to increase its pH.