A water storage tank in a distribution system is filled at a rate of 300 m3/h. The chlorine concentration of the water entering the tank from the treatment plant is 6 mg/L. Chlorine reactions with organic and inorganic constituents are first order with respect to chlorine and the average rate constant is 0.004 h-1. Find the chlorine concentrations at:
--The end of filling the storage tank if the volume at the beginning of the fill period is 200 m3
--The end of the next storage period of of 10 h (assume no withdrawal)
--As a function of time during withdrawal from the storage tank if the rate of withdrawal is 500 m3/h.