What is the size of paicle is rapid sand filter?
The effective size of the sand paicle is 0.4-0.7 mm in case of the rapid sand filter and 0.2-0.3 mm in case of the slow sand filter. (PARK TB 25th edition pg 774)
0.1 mm
0.2
0.5
0.4 to 0.7 mm
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