Feature of slow filter (w.r.t. fast filter) is/are : a) Occupies less spaceb) Highly skilled operationc) Poor bacterial qualityd) Takes more time for purificatione) Size of sand is smaller: (A) de, (B) bc, (C) cd, (D) bd
Answer is A. Slow sand filter occupies large area (more space).
Slow and filter requires less skilled operation.
Slow sand filter removes more bacteria and has better bacterial control (99.9-99.99%)
Slow sand filter requires longer duration for purification.
Size of sand is smaller (0.2-0.3 mm).