If a water treatment plant has to treat 100 million litres of water per day, then the number of Rapid Gravity Filters required would be approximately
- A3
- B13Correct
- C23
- D33
Solution
Concept
Number of filter units
Formula
N = 1.22 √Q (Q in MLD)
Step-by-step solution
1. N = 1.22 √Q = 1.22 × √100 = 12.2. 2. Adopt about 13 units.
Explanation
Empirical rule for the number of filter beds.
Why the other options are wrong
3 is too few; 23 and 33 are too many.
Shortcut
N = 1.22√Q.
Correct answer: B) 13