MCQ Detailed View

Phosphates in sewage water cause eutrophication, leading to excessive algae growth and oxygen depletion in water bodies. One of the most effective ways to remove phosphate is by adding alum (aluminum sulfate). Alum reacts with phosphate ions to form insoluble aluminum phosphate, which settles as sludge and can be removed.

Other chemicals are less effective for this purpose. Chlorine is used to disinfect water but does not remove phosphate. Lime adjusts pH or softens water but has limited effect on phosphates. Potassium permanganate is an oxidizing agent and does not remove phosphate either.

Using alum in wastewater treatment reduces phosphate levels, prevents algal blooms, and protects aquatic life. It also helps remove suspended solids and other impurities. Alum addition is an essential method in environmental chemistry for maintaining water quality and controlling pollution.