Answer:
BOD_5 = =65.8 mg/l
Explanation:
dilution water DO level = 0.8 m/l
BOD level drop to 7.3 mg/l
we know that BOD at 5th day can be clculated by using following relation[tex]BOD_5 = \frac{(D_1 -D_2) -(B_1-B_2)(1-P)}{P}[/tex]
[tex]D_1 -D_2[/tex] - DO drop in BOD bottle
[tex]B_1-B_2[/tex] - dilution water drop
P= 30/300 = 0.1
[tex]BOD_5 = \frac{(7.3) -(0.8)(1-0.1)}{0.1}[/tex]
[tex]BOD_5 = =65.8 mg/l[/tex]