Use of coagulants such as alum

ANS:A - results in reduction of pH of the treated water.

@Md Shayan Sabri.

Alum is acidic in water and can reduce total alkalinity and pH by neutralizing carbonate and bicarbonate compounds with a greater decline in pH when applied to water with low initial total alkalinity. Its 1 doze reacts with 5.55 mg/l of alkalinity Expressed as CaCO3 and increases the CO2 content.