Problem $5(15$ points$)$:

If wastewater containing the four component streams a$,$ b$,$ c$,$ and d$,$ as tabulated below,

is to be treated at a single plant, what secondary and, if necessary, tertiary unit

operations do you think will be necessary to treat it to effluent levels of BOD$5=20$ mg$/$L$,$

SS $=20$ mg$/$L$,$ and P $=1$ mg$/$L$?$ How would you prefer to have these unit operations

lined up$?$ Provide reasons for your answer. One sentence should be sufficient to defend

each $($unit operation$)$ pick, and two to three sentences should be sufficient to defend the

proposed line$-$up$.$

If each stream were to be treated alone, to meet the effluent criteria given previously,

what secondary and, if necessary, tertiary unit operations do you think will be necessary

to treat it and why? Again, a single$-$sentence explanation would suffice.