Magachlor is present in a lake having a volume of 20,000,000m3 that is used for drinking water. This waterbody can be considered well mixed. Megachlor can beconsidered a conservitive pollutant. The currentconcentration of megachlor in the lake, is 0.004 mg/L. Flowto the lake consists of one large river flow of 80,000m3/d and flow from two treatment plants equals10,000m3/d. There is no measurable megachlor inthe iver but megachlor is present in the two treatment planteffluents. Curent megachlor fluxes to the lake from eachtreatment palnt equals 0.5 kg/day. New treatment technologiesare being installed at the treatment plants that will completlyremove megachlor from these industrial treatment plant effluentsbut these technologies will not be on-line until one year fromnow.
(a) Set up the complete mass ballance for concentratingmegachlor concentration in the lake
(b) Calculate the hydraulic residence time f the lake
(c) Estimate the megachlor concentration in the lake in oneyear (when the treatment plants come on-line).
(d) What will the concentration of megachlor be in four years?