A waste water sample diluted to 100 times with aeration water had an initial dissolved oxygen (DO) of 7.0 mg/l and after 5 days of incubation at 20Â°C, the DO was zero. The BOD of waste water is :

A waste water sample diluted to 100 times with aeration water had an i

1.	A waste water sample diluted to 100 times with aeration water had an initial dissolved oxygen (DO) of 7.0 mg/l and after 5 days of incubation at 20Â°C, the DO was zero. The BOD of waste water is :
A.	700 mg/l
B.	100 mg/l
C.	cannot be determined
D.	7mg/l
Answer» B. 100 mg/l

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A waste water sample diluted to 100 times with aeration water had an initial dissolved oxygen (DO) of 7.0 mg/l and after 5 days of incubation at 20Â°C, the DO was zero. The BOD of waste water is :

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