Period of cleaning of slow sand filters is about
A. 24 - 48 hours
B. 10 - 12 days
C. 2 - 3 months
D. 1 - 2 year
Answer: Option C
A. 24 - 48 hours
B. 10 - 12 days
C. 2 - 3 months
D. 1 - 2 year
Answer: Option C
The distribution mains are designed for
A. Maximum daily demand
B. Maximum hourly demand
C. Average daily demand
D. Maximum hourly demand on maximum day
Sewage treatment units are designed for
A. Maximum flow only
B. Minimum flow only
C. Average flow only
D. Maximum and minimum flow
A. 4.5 to 6.0
B. 6.5 to 8.0
C. 8.5 to 10.0
D. 10.5 to 12.0
Option 1 and 2 is not right because bacteria formation in slow sand filters will take 10 to 12 days
Years together also is not advisable because efficiency will be down
So option c is right
Explain