Radon from well water may pose a radiological health hazard. One treatment technique is simply to hold the water in storage, allowing the radon to decay. The decay rate is first order: Rn>products;k=0.16day^-1 Consider a situation in which water is delivered from a well to a household at a rate of 0.8m3day -1. The radon concentration is to be reduced by storage to 6 percent of its level in the untreated supply.
a) How large must the storage tank be if it acts as a plug-flow reactor?
b) How large must the storage tank be if it actss as a completely mixed flow reactor?
c) If the storage tank system consists of two identical CMFRs in series, how large must each be to achieve the desired level of control?