Question

9) 8 points - Atrazine (N-phosphorylated) dissolves into a St.Clair River flowing at an average velocity of 0.8 m/s. Will biodegradation significantly decrease the concentration of Atrazine in the river over a 40-km reach (i.e. calculate the percentage loss by biodegradation) (Aerobic degradation rate for Atrazine is 0.22 per day). (1) ūpe Approximate range due In part to variability in reactant/product concentrations 600 10 eduction eduction

Answer 1

Given that,

Atrazine, which is widely used a herbicide in agriculture, is dissolved in St.Clair River.

Velocity of the flow of the river, v = 0.8 m/s

The length of the river, l = 40 km = 40000 m

We know that when atrazine is dissolived in a water body like river, there will be biodegradation of atrazine by the microbial groups. This biodegradation depends on the strength of the water and the amount of atrazine in the influent.

Given that, the aerobic degradation rate of atrazine is 0.22 per day.

Therefore, percentage loss by biodegradation = (velocity of flow of the river * aerobic degradation rate of atrazine)/length of the river ) * 100 = ((0.8* 0.22)/40000) * 100 = 0.00044 %