Which water treatment process involves adding aluminium sulphate (alum) to clump together fine suspended clay particles?
Answer and explanation
Correct answer: D. Coagulation and flocculation
- Step 1: Alum neutralizes negative charges on suspended colloidal clay particles, causing them to aggregate into heavier flocs. Step 2. These larger flocs settle rapidly to the bottom during sedimentation. Answer: Coagulation and flocculation. Why not the others: Chlorination disinfects water by killing bacteria; aeration adds dissolved oxygen and removes odours; fluoridation protects teeth.
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