Subsurface soil at a site is contaminated with diesel fuel at a concentration of 1800 mg/kg. Above-ground remediation, using slurry bioreactors, is proposed. The treatment system is required to handle a slurry flow rate of 0.04 m3/min. The required final diesel concentration in the soil is 100 mg/kg. The reaction is first-order with a rate constant of 0.1/min, as determined from a bench-scale study. Four different configurations of slurry bioreactors in the PFR mode are considered. Determine the final effluent concentration from each of these arrangements and if it meets the cleanup requirement:


a. One 4-m^3 reactor

b. Two 2-m^3 reactors in parallel (each receives 0.02 m3/min flow)

c. One 1-m^3 reactor and one 3-m^3 reactor (each receives 0.02 m^3/min flow) in parallel.

d. One 1-m^3 reactor and one 3-m^3 reactor (the smaller one receives 0.01 m^3/min flow and the other receives 0.03 m^3/min) in parallel