A lagoon with volume $1,200m^3$ has been receiving a steady flow of a conservative waste

at a rate of $100\frac{m^3}{?}$ day for a long enough time to assume that steady$-$state conditions

apply. The waste entering the lagoon has a concentration of $10m\frac{g}{L}.$ Assuming com$-$

pletely mixed conditions,

$($a$)$ What would be the concentration of pollutant in the effluent leaving the lagoon?

$($b$)$ If the input waste concentration suddenly increased to $100m\frac{g}{L},$ what would the

concentration in the effluent be $7$ days later?

$($c$)$ Repeat the above problem but for a nonconservative pollutant with

reaction rate $k=\frac{0\mathrm{.}20}{?}$ day