The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology （RSM）. The three parameters namely temperature of 33℃...The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology （RSM）. The three parameters namely temperature of 33℃, agitation of 150 r/min, and pH of 5 were chosen as center point from the previous study of fungal treatment. The experimental data on chemical oxygen demand （COD） removal （%） were fitted into a quadratic polynomial model using multiple regression analysis. The optimum process conditions were determined by analyzing response surface three-dimensional surface plot and contour plot and by solving the regression model equation with Design Expert software. Box-Behnken design technique under RSM was used to optimize their interactions, which showed that an incubation temperature of 32.5℃, agitation of 105 r/min, and pH of 5.5 were the best conditions. Under these conditions, the maximum predicted yield of COD removal was 98.43%. These optimum conditions were used to evaluate the trail experiment, and the maximum yield of COD removal was recorded as 98.5%.展开更多
The feasibility of using CASS technique for treating domestic sewage at low temperatures was investigated. The results indicate that for domestic sewage (averagely, ρ(BOD5)=295.7 mg/L; ρ(CODCr )= 811.7 mg/L; ρ(SS)=...The feasibility of using CASS technique for treating domestic sewage at low temperatures was investigated. The results indicate that for domestic sewage (averagely, ρ(BOD5)=295.7 mg/L; ρ(CODCr )= 811.7 mg/L; ρ(SS)= 119.6 mg/L), the removal rates are 95.3%, 85.7%, 91%, respectively. The CASS technique is operable in a wide range of temperature (about -5～20 ℃), but φ(S) and ρ(S) values are higher at low temperature than those at normal temperature. A low temperature is good for oxygen transmission and the cyclic fluctuation of DO (dissolved oxygen) is benefit for the removal of P and N, preventing the sludge from bulking.展开更多
文摘The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology （RSM）. The three parameters namely temperature of 33℃, agitation of 150 r/min, and pH of 5 were chosen as center point from the previous study of fungal treatment. The experimental data on chemical oxygen demand （COD） removal （%） were fitted into a quadratic polynomial model using multiple regression analysis. The optimum process conditions were determined by analyzing response surface three-dimensional surface plot and contour plot and by solving the regression model equation with Design Expert software. Box-Behnken design technique under RSM was used to optimize their interactions, which showed that an incubation temperature of 32.5℃, agitation of 105 r/min, and pH of 5.5 were the best conditions. Under these conditions, the maximum predicted yield of COD removal was 98.43%. These optimum conditions were used to evaluate the trail experiment, and the maximum yield of COD removal was recorded as 98.5%.
文摘The feasibility of using CASS technique for treating domestic sewage at low temperatures was investigated. The results indicate that for domestic sewage (averagely, ρ(BOD5)=295.7 mg/L; ρ(CODCr )= 811.7 mg/L; ρ(SS)= 119.6 mg/L), the removal rates are 95.3%, 85.7%, 91%, respectively. The CASS technique is operable in a wide range of temperature (about -5～20 ℃), but φ(S) and ρ(S) values are higher at low temperature than those at normal temperature. A low temperature is good for oxygen transmission and the cyclic fluctuation of DO (dissolved oxygen) is benefit for the removal of P and N, preventing the sludge from bulking.
