(a) Municipal sewage: flow=7500 m3/day (2.0 million gal/day); S0 (BOD)=300 mg/L; Soluble BOD=100; F/M=0.3; Xv=2500 mg/L; Se (soluble)=10 mg/L; K=8/day at 20°C.
(b) Olive mill wastewater: flow=450 m3/day (0.12 MG/day); S0 (BOD)=8000 mg/L; K=2.6/day at 20°C; estimated MLVSS=3500 mg/L.
Detention time is:
2500 x 0.3
Average reaction rate if will be:
The new detention time is 0.4x7500/7950=0.38. The influent to the plant to meet the permit can be calculated:
The concentration of BOD in the pretreated mill wastewater can then be calculated by a material balance:
Qs (S0,s)+Qi (S0,i)=Qs+Qi) S0,s+i 7500(100)+450(Sw)=7950(325)
S0 i=4075 mg/L
Pretreatment is required to reduce about 50% of the BOD in the mill wastewater. (c) Temperature effects: Determine the change in MLVSS that will be required when the temperature coefftcient 6 increases from 1.015 to 1.04 due to an increase in soluble mill wastewater BOD:
The increase in MLVSS can be calculated as: 1.48
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