1. A contaminant steadily enters a lake with a hydraulic residence time of 2 weeks. The lake discharges to a river that
Posted: Wed Jun 08, 2022 6:49 am
1. A contaminant steadily enters a lake with a hydraulic residence time of 2 weeks. The lake discharges to a river that has an average flow velocity of 30 km per day and that empties into the ocean after traveling 150 km. The contaminant concentration has been determined to be 50 µg/L at the outlet of the lake and 10 µg/L at the outlet of the river. (a) Draw a process flow diagram. (2 pts) (b) Assuming that the lake and river can be modeled as a CSTR and a PFR, respectively, and that the contaminant decays by a first-order reaction, find the contaminant concentration in the water entering the lake. (13 pts)