VERSION A

$(25$ points$)$ Engineers are tasked with designing the disinfection contact chamber for a new

treatment plant that will supply $1\mathrm{.}3{10}^6\frac{L}{h}$ of purified water. Space and budget constraints have

limited their options considerably. Consider the following two options and determine the

treatment level each will provide for inactivating Cryptosporidium.

I. A PFR chlorine dosing chamber that has a volume of $75m^3$ and utilizes HOCl as a

disinfectant. The HOCI has a coefficient of specific lethality of $3\mathrm{.}1\frac{L}{g}*s$ and is

dosed at $2\mathrm{.}25m\frac{g}{L}.$

$C=2\mathrm{.}25L,K={3\mathrm{.}1}^L$

$V=75N,+==\frac{V}{Q}=\frac{75}{1\mathrm{.}310}$

$Q={1\mathrm{.}3110}^6,$

II$.$ A CSTR ozone dosing chamber with a volume of $180m^3$ that uses ozone as a

disinfectant, which has a coefficient of specific lethality of $1\mathrm{.}8\frac{L}{m}g*s.$ This reactor

is dosed with $1\mathrm{.}4m\frac{g}{L}$ of $O_3.$