Question

A sample of wastewater is diluted 10 times. The diluted solution has an ultimate biochemical oxygen demand (BOD), Lo, of 30 mg/L and a reaction rate constant, k, of 0.20/d. The values of ultimate BOD and the reaction rate constant of the original wastewater are most nearly _____.

Answer 1

474.59 mg/L

Step-by-step explanation:

Given that

BOD = 30 mg/L

Original BOD = 30 mg/L × dilution factor

Original BOD = 30 mg/L × 10 = 300 mg/L

`L_o = (BOD)/(1-e^(-5t))`

here
`L_o` is the ultimate BOD ; BOD is the biochemical oxygen demand ; t = 0.20 /day

`L_o = (300)/(1-e^(-5(0.20)))`

`L_o = 474.59 \ mg/L`