Use engineering problem solving method. Suppose you are to design a chlorination tank for killing microorganisms in the effluent from a wastewater treatment plant. It is necessary to achieve $99\mathrm{.}99\%$ kill in a wastewater flow of $100$ m$3/$hr$.$ Assume the disinfection is a first$-$order reaction with a rate of $0\mathrm{.}2$ min$-1.$

a$.$ Calculate the tank volume if the contact tank is a CSTR reactor.

b$.$ Calculate the tank volume if the contact tank is a plug$-$flow reactor.

c$.$ What is the detention time of both reactors?