Question

A 40 L water tank is chlorinated by feeding in a solution of 20 ppm free chlorine. Some of the free chlorine reacts with the plastic water tank, consuming 1.1 µg of free chlorine/min. The remaining “spent” chlorine is removed at a flowrate of 55 mL/min and a concentration of 4.0 ppm. Volume is maintained by adding makeup water at a flowrate equivalent to the net volume loss. Assume the density of all streams is 1000 kg/m3 . If the system is to operate at steady state (accumulation = 0), what flowrates (mL/min) of feed and makeup water are needed?

Answer 1