Definition : The process of mixing certain chemicals to water to neutralise the electrical charges and to form an insoluble, gelatinous flocculent precipitate for absorbing add en-training suspended and colloidal particles of impurities is called coagulation $Q_{s n}=\ Coagulation $

Factors Affecting Coagulation

Q. What are the factors affecting coagulation?

(a) Type of coagulant.

(b) Dose of coagulant.

(c) Time and method of mixing the coagulant.

(d) Character of water.

• pH of water.

• Temperature of water.

• Nature and quantity of suspended matter.

Common Coagulants

Q. What are the common coagulants? Explain any one.

• Alum or aluminium sulphate.

• Chlorinated copperas.

• Magnesium carbonate and lime.

• Ferrous sulphate and lime.

• Sodium aluminate and lime.

• Poly electrolytes.