Civil Engineering - GATE Exam Questions - Discussion

Discussion Forum : GATE Exam Questions - Section 4 (Q.No. 5)
5.
In a BOD test, 5 ml of waste is added to 295 ml of aerated pure water. Initial dissolved oxygen (D.O) content of the diluted sample is 7.8 mg/l. After 5 days of incubation at 20°C, the D.O. content of the sample is reduced to 4.4 mg/l. The BOD of the waste water is :
196 mg/l
200 m/l
204 mg/l
208 mg/l
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
14 comments Page 2 of 2.

Sachin s Naik said:   6 years ago
The correct answer is 200.6mg/l.

Abhishek said:   4 years ago
Df = 295÷5
Bod = (intial Do-final DO) * D.F,
= 200.6.

Sharath Manohar said:   4 years ago
295/5 * (7.8-4.4) = 200 mg/l is the actual right answer.

Lencho Edeto said:   3 years ago
BOD = [DO( initial) -DO final)] * Dilution factor.
= (7.8-4.4)mg/lit * (295/5).
= 200.6 mg/lit.


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