PROBLEMS

$3\mathrm{.}1.$ An industry discharging to a POTW is required to equalize its wastewater and discharge it such that the load in BOD$/$day to the treatment plant is constant over the $24h.$ The sewage flow is $6\mathrm{.}47$ million $ga\frac{l}{d},$ with a BOD of $200m\frac{g}{l}.$ The diurnal variation in flow is shown in Fig. P$3-1.$ The industrial waste flow is $3\mathrm{.}17$ million gal$/$d$,$ with a BOD of $1200m\frac{g}{l},$ and is constant over $10h(8$ A$.$M$.$ to $6$ P$.$M$.).$

$($a$)$ Compute the volume of equalization $($or holding$)$ tank required.

$($b$)$ Plot the discharge curve of the industrial waste over $24h.$

FIGURE P$3-1$

Hours of the ds