$6-2(15$ pts$)$ Design a disinfection contactor for a direct filtration plant. Assume a tank factor of $0\mathrm{.}7.$ In

summer the plant flow is $100\frac{m^3}{m}in$ at $20C,$ and in winter the plant flow is $50\frac{m^3}{m}in$ at $0\mathrm{.}5C.$ The

plant will be run to maintain a $pH$ of $8\mathrm{.}0$ and a free chlorine residual of $1\mathrm{.}2m\frac{g}{L}$ at the end of the

contact basin. Report the overall dimensions, internal channel dimensions, and dimension ratios.