Problem $3$: During a BOD test, $2$ ml of waste water containing $25$ mg$/$L of a protein $($C$11$H$21$ON$)$

having a DO of $0\mathrm{.}0,$ was mixed with $298$ mL of dilution water having a DO of $8\mathrm{.}9$ mg$/$L$.$ After $5$

days, it was noted that the DO of test bottle is $2\mathrm{.}5$ and at the oxygen concentration of dilution

water dropped to $8\mathrm{.}7$ mg$/$l$.$ What is the BOD$5$ in this case? If the TBODu of this water is $1100,$

$($a$)$ what is the first order CBOD constant? $($b$)$ What is NBOD in mg$/$L$.$ This experiment was

conducted in the US at $20$C$.$ Determine the value of K at $15$o C$.$