Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kin...Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics pa-rameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the mod-erate-removal stage with B/C<0.1, COD removal could be described by a first order reaction. Then Monod equation was introduced to indicate COD removal. The reaction rate constant (K) and half saturation constant (KS) were 0.0208-0.0642 L/(gMLSS)h and 0.44-0.59 (gCOD)/L respectively at 20 C-35 C. Activation energy (Ea) was 6.05104 J/mol. By comparison of kinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.展开更多
In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten...In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten equation. the influence of sludge returning was considered in the design. The result shows that the parameter of sludge reflux ratio plays a very important role in the design of active sludge system. In some given conditions,there exists an optimum reflux ratio which can make the volume of aeration tank be the minimum.展开更多
A batch experiment was conducted to investigate the adsorption of an acid dye(Acid Orange 51) and a basic dye(Safranine) from aqueous solutions by the sludge-based activated carbon(SBAC). The results show that the ads...A batch experiment was conducted to investigate the adsorption of an acid dye(Acid Orange 51) and a basic dye(Safranine) from aqueous solutions by the sludge-based activated carbon(SBAC). The results show that the adsorption of Acid Orange 51 decreases at high p H values, whereas the uptake of Safranine is higher in neutral and alkaline solutions than that in acidic conditions. The adsorption time needed for Safranine to reach equilibrium is shorter than that for Acid Orange 51. The uptakes of the dyes both increase with temperature increasing, indicating that the adsorption process of the dyes onto SBAC is endothermic. The equilibrium data of the dyes are both best represented by the Redlich-Peterson model. At 25 °C, the maximum adsorption capacities of SBAC for Acid Orange 51 and Safranine are 248.70 mg/g and 525.84 mg/g, respectively. The Elovich model is found to best describe the adsorption process of both dyes, indicating that the rate-limiting step involves the chemisorption. It can be concluded that SBAC is a promising material for the removal of Acid Orange 51 and Safranine from aqueous solutions.展开更多
The two types of biological consortia--real activated sludge and laboratory adapted consortium were immobilized in polyethylene oxide cryogels. Their potential to decolorize the anionic azo dye amaranth in sequencing ...The two types of biological consortia--real activated sludge and laboratory adapted consortium were immobilized in polyethylene oxide cryogels. Their potential to decolorize the anionic azo dye amaranth in sequencing batch biofilters was studied. At a growing concentration of azo dye （20 mg·L^-1, 25 mg·L^-1, 30 mg·L^-1） the biofilters had a mean feeding rate of 30.32 ± 25.78 mL^-1·h^-1 and 13.76 ：t： 8.33 mL^-1·h^-1, respectively for immobilized adapted consortia （AC） and activated sludge （AS）. The AC-biofilter reached an overall decolorization rate of 0.211 ± 0.14 mg dye.mLLh1 and a decolorization effectiveness of 60.28 ：t： 32.42%. In contrast, the mean values for overall decolorization rate and effectiveness in AS-biofilter were 0.249 ± 0.16 mg dye.mL^-1·h^-1 and 82.48± 14.41%. The system with immobilized activated sludge had more stable process dynamics and higher tolerance to shock azo dye loading in the first stage of the process. The immobilized adapted consortium presented a good ability to adequate response at higher azo dye concentrations and loading.展开更多
文摘Aerobically activated sludge processing was carried out to treat terylene artificial silk printing and dyeing wastewater (TPD wastewater) in a lab-scale experiment, focusing on the kinetics of the COD removal. The kinetics pa-rameters determined from experiment were applied to evaluate the biological treatability of wastewater. Experiments showed that COD removal could be divided into two stages, in which the ratio BOD/COD (B/C) was the key factor for stage division. At the rapid-removal stage with B/C>0.1, COD removal could be described by a zero order reaction. At the mod-erate-removal stage with B/C<0.1, COD removal could be described by a first order reaction. Then Monod equation was introduced to indicate COD removal. The reaction rate constant (K) and half saturation constant (KS) were 0.0208-0.0642 L/(gMLSS)h and 0.44-0.59 (gCOD)/L respectively at 20 C-35 C. Activation energy (Ea) was 6.05104 J/mol. By comparison of kinetic parameters, the biological treatability of TPD wastewater was superior to that of traditional textile wastewater. But COD removal from TPD-wastewater was much more difficult than that from domestic and industrial wastewater, such as papermaking, beer, phenol wastewater, etc. The expected effluent quality strongly related to un-biodegradable COD and kinetics rather than total COD. The results provide useful basis for further scaling up and efficient operation of TPD wastewater treatment.
文摘In order to describe the relationship between dynamic process and sludge removing load in active sludge system, a new method for designing the volume of aeration tanks was put forward based on the Michaelis and Menten equation. the influence of sludge returning was considered in the design. The result shows that the parameter of sludge reflux ratio plays a very important role in the design of active sludge system. In some given conditions,there exists an optimum reflux ratio which can make the volume of aeration tank be the minimum.
基金Project(51008106)supported by the National Natural Science Foundation of China
文摘A batch experiment was conducted to investigate the adsorption of an acid dye(Acid Orange 51) and a basic dye(Safranine) from aqueous solutions by the sludge-based activated carbon(SBAC). The results show that the adsorption of Acid Orange 51 decreases at high p H values, whereas the uptake of Safranine is higher in neutral and alkaline solutions than that in acidic conditions. The adsorption time needed for Safranine to reach equilibrium is shorter than that for Acid Orange 51. The uptakes of the dyes both increase with temperature increasing, indicating that the adsorption process of the dyes onto SBAC is endothermic. The equilibrium data of the dyes are both best represented by the Redlich-Peterson model. At 25 °C, the maximum adsorption capacities of SBAC for Acid Orange 51 and Safranine are 248.70 mg/g and 525.84 mg/g, respectively. The Elovich model is found to best describe the adsorption process of both dyes, indicating that the rate-limiting step involves the chemisorption. It can be concluded that SBAC is a promising material for the removal of Acid Orange 51 and Safranine from aqueous solutions.
文摘The two types of biological consortia--real activated sludge and laboratory adapted consortium were immobilized in polyethylene oxide cryogels. Their potential to decolorize the anionic azo dye amaranth in sequencing batch biofilters was studied. At a growing concentration of azo dye （20 mg·L^-1, 25 mg·L^-1, 30 mg·L^-1） the biofilters had a mean feeding rate of 30.32 ± 25.78 mL^-1·h^-1 and 13.76 ：t： 8.33 mL^-1·h^-1, respectively for immobilized adapted consortia （AC） and activated sludge （AS）. The AC-biofilter reached an overall decolorization rate of 0.211 ± 0.14 mg dye.mLLh1 and a decolorization effectiveness of 60.28 ：t： 32.42%. In contrast, the mean values for overall decolorization rate and effectiveness in AS-biofilter were 0.249 ± 0.16 mg dye.mL^-1·h^-1 and 82.48± 14.41%. The system with immobilized activated sludge had more stable process dynamics and higher tolerance to shock azo dye loading in the first stage of the process. The immobilized adapted consortium presented a good ability to adequate response at higher azo dye concentrations and loading.
