(Solved): (10 p.) A conventional surface water treatment plant must achieve 99.99% virus removal. The free ch ...

(10 p.) A conventional surface water treatment plant must achieve $99.99\%$ virus removal. The free chlorine concentration remaining in the effluent from the disinfection basin is $1.0\mathrm{mg}/\mathrm{L}$. The raw water has a pH of 8 with a temperature of $5{}^{\circ }\mathrm{C}$. Estimate the total daily chlorine use at the disinfection basin ( $\mathrm{kg}/\mathrm{d})$ if the treatment plant has a design flow of $40000{\mathrm{m}}^3/\mathrm{d}$. The disinfection basin has a total volume of $250{\mathrm{m}}^3$.