As a process engineer, you are designing a new drinking water treatment plant using conventional treatment process including Two Rapid Mixers as follows:

The design flow is $50$ million gallons per day $($MGD$)$ Gallon $=3\mathrm{.}785L,1m^3=1000L).$

The average temperature of water is $5C$ with a dynamic viscosity,

$=1\mathrm{.}519{10}^{-3}$

Pa$.$Sec

In each rapid mixer with a square shape, detention time, $=1$min, water depth $H=13ft,$ and power input $)$

The equivalent diameter, $T_E$ for each rapid mixer is m$.T_E=2\sqrt[\phantom{2}]{\frac{A}{}}$

$1)4\mathrm{.}4$

$0\mathrm{.}4$

$4\mathrm{.}6$

$4\mathrm{.}1$