state gov TSPSC Polytechnic Lecturer Mock Test 2022 Environmental Engineering Sewage Sewage Treatment
A waste water sample of 2 ml is made upto 300 ml in BOD bottle with distilled water. Initial DO of the sample is 8 mg/l and after 5 days it is 2 mg/l, its BOD is
1
894 mg/l
2
900 mg/l
3
300 mg/l
4
1200 mg/l