engineering recuitment UKPSC Polytechnic Lecturer Mock Test 2024 Environmental Engineering Sewage Sewage Treatment
One litre of sewage, when allowed to settle down for 30 minutes give sludge of 27 cm3. If the dry weight of sludge is 3.0 gm, then its sludge volume index will be -
1
30
2
9
3
24
4
81