Plug flow reactors

$4.$ Disulfoton is a common insecticide used in agricultural systems. During rainstorms, runoff results in input of a non$-$point source and a point source of disulfoton, as shown in the figure below. The boundary condition at $x=0$ is $C_0=0\mathrm{.}05m\frac{g}{L}.$ Assume that disulfoton decays at a rate of $\frac{0\mathrm{.}1}{?}$ day.

Present a complete mass balance approach.

a$.)$ Derive the steady$-$state expression for disultoton concentration as a function of distance from $x=0$ to $x=10km($point A$).$

b$.)$ Determine the steady$-$state disulfoton concentration just before point $A.$

c$.)$ Derive the expression for disulfoton concentration as a function of distance from $x=10km($point A$)$ to $x=25km($point B$).$

d$.)$ Determine the steady$-$state disulfoton concentration just before the injection at point B$.$

e$.)$ Determine the steady$-$state disulfoton concentration for the mixing zone at point B$.$

f$.)$ Derive the expression for disulfoton concentration as a function of distance from $x=25km($point B$)$ to $x=35km($point C$).$

g$.)$ Make a plot of the disulfoton concentration in the river water as a function of $x$ over the range of $x=0$ to $35km.$ I suggest you use MATLAB, however, you are welcome to use a program of your choice.

h$.)$ Does the disulfoton concentration in the river exceed the drinking water standard? If so$,$ where?