22. (a) Data is collected over a stretch of a river after an outfall introducing waste at a point distance, x= 0km. The Table below provides numbers of bacteria as the water flows downstream. If the river is simulated as a Plug Flow system and stream velocity (U=m/d) what is the death rate coefficient Kd(d1) of the bacteria in the river. Use the Plug Flow Compartment Tool in AQAUSIM ver 2.3 to determine the unknown parameter. (15pts) (MPN = most probable number of bacteria as determined by a multiple tube technique) (b) For the system described in '(a)' above, perform a sensitivity analysis of the determined parameter. Create a graph showing the 95% confidence limits of the simulated regression line. (40 pts) (c) Evaluate the movement of a pollutant through a soil column (vadose zone) for a semipermeable soil material using simulations already in use in AQUASIM, ASPEN or other programmes. We are assuming the soil is fully saturated with insignificant verticle flow. We start with a loading of 100 g/d from the top with a dispersion coefficient of 1m2/d. (45pts)