污水处理 化工 毕业设计论文 中英文 外文 资料 文献 翻译doc.docVIP

污水处理 化工 毕业设计论文 中英文 外文 资料 文献 翻译 development of a novel modified EGSB reactor for municipal sewage treatment at ambient temperatures 　　　In recent years，anaerobic treatment has become an attractive sustainable wastewater treatment technology due to its low energy consumption and biogas production.In particular,the application of the up?flow anaerobic sludge blanketUASBand the conventional expand granular sludge bedEGSBc in domestic wastewater treatment has gained much more attention.The EGSBc is generally more efficient in COD reduction,and more resistant to shock organic loading ratesOLRas well as the changes of temperature and pH than the UASB.However,the very high water velocity in the three-phase separator of EGSBc ,which is caused by the high Vup and methane bubble production,ofen leads to a significant washout of biomass and thus a high COD concentration in the effluent.As a result,the efiuent quality sometimes can not meet the discharge standards for municipal wastewater treatment plants or the biological treatment system eventually collapses .Therefore,the key problem for EGSBc in municipal sewage treatment is to control the loss of biomass under a high up-flow velocity． 　　　In this paper,a modified EGSB reactor was developed by combining the advantages of the UASB and EGSBc reactors.Pilot-scale study was carried out for both EGSBm and EGSBc reactors under ambient conditions for the purpose of comparison.The effluent of a primary sedimentation tank in the Dongqu municipal sewage treatment plant was used as influent.The hydrodynamic characteristics in EGSBm were analyzed by Retention Time DistributionRTDexperiments and the Polvmerase Chain Reaction.Denaturing Gradient Gel Electrophoresis PCR-DGGE technique was used to explore the microbial diversity in the granular sludge． 1 Materials and Methods 1.1 Sources of Biomass and Feed Influent 　　　Mesophilic anaerobic granular sludge was obtained from a ful1-scale internal circulation bioreactor treating citric aci