A completely mixed activated sludge process is to be used totreat a flow rate of 2.5 MGD. Design a rectangular activated sludgereactor with a 4:1 ratio of length to width. (design only 1 reactorfor all flow). The effluent from the plant must not exceed 15 mg/Lof BOD5. Use the following design criteria:
a. BOD5 influent = 250.0 mg/L
b. MLVSS (X) = 3500 mg/L
c. Reactor depth = 11 ft
d. Effluent BOD5 must be less than 20 mg/L
e. Y = 0.6 mg VSS/mg BOD5
f. K = 6 day-1
g. KS = 65 mg/L BOD5
h. Kd = 0.08 day -1
i. MLVSS/MLTSS = 0.75
Determine the following: a. Determine the minimum solidsretention time (SRT) in days to meet discharge criteria
b. If the actual solids retention time is 4 days, what would bethe volume of the activated sludge basin if the wasting flow rateis 40,000 gpd containing 6,400 mg/L of solids.
c. Using the volume of aeration basin in question (b) determinethe dimensions of the basin, if the depth is 11 feet, to thenearest even foot
d. What is the hydraulic retention time (HRT) in hours, in theactivated sludge basin?
