A strain of bacteria has been isolated that can cometabolize

A strain of bacteria has been isolated that can cometabolize tetrachloroethane (TCA). This strain of bacteria can be used for the bioremediation of hazardous-waste sites contaminated with TCA. Assume that the biodegradation rate is independent of TCA concentration (i.e., the reaction is zero order). In a bioreactor it is observed that the rate for TCA removal was 1 g/L-min. What water retention time would be required to reduce the concentration from 1 mg/L in the influent to 10 g/L in the effluent of a reactor? Assume the reactor is completely mixed

Solution

TCA Removal per second                = 1µg/60s
Difference of TCA amounts between initial and final waters= 1000µg - 10µg
= 990µg
Time required for removing 990µg from water       = 990µg/(1µg/60s)
= 59400 S = 990min.