Question

A lagoon is designed to accommodate an input flow of 0. 1 m3
/s of a non-conservative
pollutant with concentration 30 mg/lt. and reaction rate constant of 0.2 per day. The effluent
from the lagoon must have a pollutant concentration of less than l0 mg/lt. assuming that
complete mixing takes place, how large must the lagoon be?

Answer 1

Answer:

Transcribed image text: A lagoon is to be designed to accommodate an input of 0.10 m3/s of a non- conservative pollutant with a concentration of 30.0 mg/L and reaction rate constant of 0.20/day. The effluent from the lagoon must have a pollutant concentration lower than 10 mg/L. Assuming complete mixing and steady-state conditions, perform a mass balance to obtain the following: a. (10) How large must the lagoon be to meet the desired effluent concentration if you decide to build a CSTR? (Do the mass balance). b. (5) What will the volume be if you decide to build a PER? C. (5) At the end, you decide to build a CSTR with the volume that you found in (a). However, you notice that after operating the reactor for a few weeks the effluent concentration is 1 mg/L. Because the design parameters haven't changed, you conclude that the kvalue used for the design was not accurate. What will the true value of k be if the effluent concentration is 1 mg/L?