Question $1$

Define and differentiate between:

a$.$ Aerated and facultative lagoons

b$.$ Organic, Poly and Ortho Phosphorus

c$.$ Total Nitrogen, TKN and Ammonia$-$Nitrogen

d$.$ HRT and SRT in Biological treatment systems

e$.$ An industry produces $800\frac{m^3}{?}$ day of organic waste with a $BO{D}_5$ of $635m\frac{g}{L}.$ If wastes with $BO{D}_5$ less than $300m\frac{g}{L}$ are covered by basic sewer charges, through taxes or as part of the water bill, what annual surcharge would this industry pay if the operating cost for removing BODs is $$\frac{0\mathrm{.}25}{k}gBO{D}_5$ removed?

Question $2$

$($i$)$ A community normally levies a sewer charge of $20$ cents $\frac{?}{m^3(\text{\$}\frac{0\mathrm{.}20}{m^3})}.$ For discharges in which the BOD $>250m\frac{g}{L}$ and suspended solids $(SS)>300m\frac{g}{L},$ an additional $$\frac{0\mathrm{.}50}{k}g$ BOD and $$\frac{1\mathrm{.}00}{k}g$ SS are levied.

A chicken processing plant uses $2000m^3$ of water daily and discharges wastewater with BOD$=480m\frac{g}{L}$ and $SS=1530m\frac{g}{L}.$ What is the plant's daily wastewater disposal bill?

$($ii$)$ An industry is being established and they must treat the wastewater generated from their product production process. Since the industry has not been built yet, there is no waste generation data. How would you go about getting the information you need to arrive at waste generation and liquid flow rates?

Question $3$

$($i$)$ One hundred cubic meters per day $(100\mathrm{.}0\frac{m^3}{d})$ of mixed sludge at $4\mathrm{.}0$ percent solids is to be thickened to $8\mathrm{.}0$ percent solids. What is the approximate volume of the sludge after thickening?

$($ii$)$ Determine the concentration of the effluent $BO{D}_5$ for the two$-$stage trickling filter described below. The wastewater temperature is $20C.$ Assume the NRC equations apply.

Design flow $=0\mathrm{.}0509\frac{m^3}{s}$

Influent $BO{D}_5($after primary treatment$)=260m\frac{g}{L}$

The diameter of each filter $=24\mathrm{.}0m$

Depth of each filter $=1\mathrm{.}83m$

The recirculation flow rate for each filter $=0\mathrm{.}0594\frac{m^3}{s}$