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What is True about slow sand filter is - and explain in detail?
Option A - wrong, slow sand filter occupy more space Option B - wrong, it is less expensive Option C - correct, rate of filtration is very slow (2-3m.g.a.d.) hence takes longer time Option D - wrong, effective sand size in slow sand filter is 0.2-0.3 mm (PARK TB 25th edition pg 773)