Data from a field study on a step-feed activated-sludge secondary are as follows:Aeration...

Data from a field study on a step-feed activated-sludge secondary are as follows:

Aeration tank volume = 2800m3

Settled wastewater flow = 13,1100 m3/d

Wastewater temperature = 20° C

Return sludge flow = 4800 m3/d

Waste sludge flow = 72 m3d

MLSS in aeration tank = 2350 mg/l

SS in waste sludge = 14,000 mg/l

Influent wastewater BOD = 128 mg/l

Effluent wastewater BOD = 22 mg/l

Effluent SS = 26 mg/l

Using these data, calculate the BOD loading and F/M ratio, operational parameters of sludge age, aeration period and return sludge rate, and BOD removal efficiency. Calculate the excess sludge production in kilograms of excess suspended solids per kilogram of BOD applied and compare this value with that given in Figure 13.1.