Question

What is the frequency of cleaning of a slow sand filter?

(a) 1 week

(b) 1-3 months

(c) 2-3 days

(d) 2-3 weeks

The question was asked during an internship interview.

My enquiry is from Slow Sand Filter topic in chapter Filtration of Environmental Engineering

Answer 1

Right choice is (b) 1-3 months

For explanation I would say: The slow sand filter requires cleaning, depending upon the impurities present in water and normally it is done after 1-3 months.