The effluent quality from a secondary clarifier in an activated sludge process depends on the performance in the secondary clarifier at great extent. Several models have been developed based on the Kynch solid flux th...The effluent quality from a secondary clarifier in an activated sludge process depends on the performance in the secondary clarifier at great extent. Several models have been developed based on the Kynch solid flux theory to improve the clarifier performance at last decades. This paper proposed a model which is established according to the basis sedimentation process of the secondary clarifier and Kynch flux theory for a clarifier with feedwell in upper of tank and the diffusion effective are combined into the model, which benefts the further improvement of the model and makes the solutions fit to the measurement data in secondary clarifier,展开更多
In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(...In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.展开更多
文摘The effluent quality from a secondary clarifier in an activated sludge process depends on the performance in the secondary clarifier at great extent. Several models have been developed based on the Kynch solid flux theory to improve the clarifier performance at last decades. This paper proposed a model which is established according to the basis sedimentation process of the secondary clarifier and Kynch flux theory for a clarifier with feedwell in upper of tank and the diffusion effective are combined into the model, which benefts the further improvement of the model and makes the solutions fit to the measurement data in secondary clarifier,
基金Supported by the College of Scientific Innovation Significant Cultivation Fund Financing Projects(No.708047)the Key Special Program for Pollution Control(No.2012ZX07101-003)
文摘In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.
