Question

How do I find a decay rate constant(K) and ultimate BOD if all I am given are the temperature, ml of solution, initial and the final DO of two samples after 7 days. (One diluted one not).

Answer 1

Rate Constant (K) depends upon the following .i.e.

it depends upon the reaction involved

it depends upon the type of Bacteria in case of BOD as more the BOD more poor is the quality of water

it also depends upon the temperature

Rate = - Δ[organic]/Δtime = K[organic]^-1

On the other hand “ultimate BOD” is the amount of oxygen (O₂) required to decompose all of the organic material after “infinite time”.

This is usually simply calculated form the 5 or 20 day data.

BODE(BOD exerted) = BOD (1- e^-kt)

If temperature and intial and final DO of two sample is given then rate depends on these factors as from these factors rate is calculated.(One diluted one not)