This problem is in reltation to Environmental Engineering. If you could show all steps to better help with understanding that would be greatly appriciated. Thanks so much in advance.

Problem $1(5$ points$)($category: flocculation settling$)$: Determine the detention time and overflow rate for a settling tank that will reduce the influent suspended solids concentration from $33\mathrm{.}0$ mg$/$L to $15\mathrm{.}0$ mg$/$L$.$ Batch settling column data $($for a column of $4\mathrm{.}5$ m$)$ were acquired and analyzed into iso$-$concentration lines showing percent removal. Hint: you only need to determine the total percent removal for the $30\%$ and $40\%$ iso$-$concentration lines, then linearly interpolate.