A tank containing a pollutant is leaking into a river that feeds directly into a drinking water treatment plant (WTP). You were hired to develop a solution to degrade the pollutant in the WTP. For simplicity, assume the WTP can be modeled as a CSTR with a volume of 2,000 m3 and flowrate in and out of the WTP equal to 150 m3/day. (a) On your first day at the WTP, you measure the concentration of the conservative pollutant coming into the WTP (influent) as 15 mg/L. Assuming that the system is at steady-state on your first day, what is the pollutant concentration leaving(effluent)the WTP (show all work to receive full credit)?

(b) On day two, a second tank of toxic pollutant begins leaking. The pollutant concentration in the WTP influent suddenly increases to 100 mg/L. What would be the conservative pollutant concentration (mg/L) in the WTP effluent6daysafter this change occurred (assume the influent concentration remains constant at 100 mg/L during the 6 days)?

(c) After the period of 6 days in part (b), you come up with a novel solution to degrade this pollutant in the WTP. The process you develop results in a first order decay with a reaction rate constant of k = 0.8 / day. How many days from this point will it take for the effluent pollutant concentration to decrease to 10mg/L assuming that the influent concentration remains constant at 100 mg/L?