excessive negative head
mud ball formation
higher turbidity in the effluent
low temperature
0.2 to 0.4
0.4 to 1.0
2 to 4
5 to 7
24 - 48 hours
10-12 days
2-3 months
1-2 year
less than that of slow sand filters
in between the filtration rate of slow sand filters and rapid sand filters
greater than that of rapid sand filters
equal to that of slow sand filters
to increase the filtration slow sand filters capacity of
to increase the filtration rapid sand filters capacity of
for isolated buildings like pools, hotels etc swimming
all of the above