Pools and Ripples:

There is a creek that can be modeled as a pool followed by a riffle. While the creek has no

suspended sediments in the pool portion, a tributary containing $10,000m\frac{g}{L}$ of sediment

feeds into the creek before the riffle section. The flow rate of the creek prior to the tributary

intersection is $75\frac{L}{s}$ and the flow rate of the tributary is $25\frac{L}{s}\mathrm{.}500L$ of benzene is spilled

into the creek at the entrance of the pool section. The tributary contains no benzene.

Overall liquid phase mass transfer coefficient $=0\mathrm{.}3c\frac{m}{h}$

Sediment$-$water partition coefficient $=41\frac{L}{k}g$

Pool: $a_v=200c{m}^{-1},=50s$; Riffle: $a_v=70c{m}^{-1},=100s$

$($a$).($calculation$)$ What is the fraction of benzene desorbed to the air by the end of the creek?

$($b$).($short answer$)$ How does the fraction of benzene desorbed to the air change if $1000L$ of

benzene was spilled instead of $500L$ of benzene? Why?