An oxidation ditch has a flow of 11.5 mgd, an influent BOD of 200 mg/l, and 35 mg/l of a...

An oxidation ditch has a flow of 11.5 mgd, an influent BOD of 200 mg/l, and 35 mg/l of ammonia, and effluent of 10 mg/l. Wastewater nitrifies year-round at a temperature of 16°C. The two ditches (Figure 11-30) have four brush aerators each operating at average conditions (Table 11-5). Use an of 0.9. The residual DO is 4.0. Calculate the values for oxygen demand, oxygen transfer, and hp for each brush.