In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewat...In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered.Two stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient option.The employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended biomass.The results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal rate.Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal performance.The sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,respectively.The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,respectively.Also,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.展开更多
Particle size analyzer,scanning electron microscope were used to investigate the dynamic membrane composition and filtration performance under optimal operation parameters.Energy dispersion spectroscopy was used to de...Particle size analyzer,scanning electron microscope were used to investigate the dynamic membrane composition and filtration performance under optimal operation parameters.Energy dispersion spectroscopy was used to determine the elemental composition of the dynamic membrane.The results indicated that the mass concentration of cake layer was 39.27 g·m-2,with contents of colloid,volatile suspended solids and inorganic matter 5.75 g·m-2,26.5 g·m-2 and 7.02 g·m-2 respectively.Self-generated dynamic membrane mainly consisted of porous structure with high porosity.Filamentous bacteria which acted as matrix of dynamic membrane structure could be obviously observed.Most of the particle size range from 70μm to 130μm.O,K,Na,Ca,P,S,Cl,Mg,Si were the main elements in the dynamic membrane.展开更多
基于目前短程硝化–厌氧氨氧化(partial nitritation and anammox, PN/A)工艺处理城镇污水中反应器运行不稳定和氮去除负荷低的问题,本文设计一种新型复合生物反应器:序批式–折流板–分置膜生物反应器(sequencingbatch-baffled-separat...基于目前短程硝化–厌氧氨氧化(partial nitritation and anammox, PN/A)工艺处理城镇污水中反应器运行不稳定和氮去除负荷低的问题,本文设计一种新型复合生物反应器:序批式–折流板–分置膜生物反应器(sequencingbatch-baffled-separatemembranebioreactor,SASMBR)。将该反应器应用于PN/A工艺处理城镇污水,探究反应器的性能,并对SASMBR运行PN/A工艺的运行成本进行分析。结果表明,采用SASMBR反应器运行PN/A工艺处理城镇污水,能够实现高效稳定的脱氮效果,TN去除率达到80%~85%,氮素去除负荷(nitrogenremovalrate,NRR)达到0.20~0.22kgN/(m-3·d-1),出水TN浓度维持在8 mg/L以下。16SrRNA基因测序分析发现,短程硝化SASMBR反应器内设置的折流板能够富集氨氧化细菌(ammoniaoxidationbacteria,AOB),确保短程硝化SASMBR反应器的良好性能;厌氧氨氧化SASMBR内固定在折流板两侧的无纺布可以有效地持留厌氧氨氧化菌(ammoniumoxidizingbacteria,AnAOB),同时,厌氧氨氧化SASMBR内丰度升高的AOB可以为AnAOB提供生长的厌氧环境和NO2--N基质,使厌氧氨氧化SASMBR反应器能够快速启动和高效稳定运行。SASMBR的运行成本为0.037元/m3,比传统城镇污水处理厂的运行成本大幅度降低。展开更多
基金supported by Takmiliran textile dyeing factory(272219601)Materials and Energy Research Center(MERC)(99392003).
文摘In this study,the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic-aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered.Two stage processes performed better than one stage ones,both in terms of overall organic and color removal,as well as the higher contribution of anaerobic stage to the overall removal performance,thereby making them a more energy efficient option.The employment of a moving bed sequencing batch biofilm reactor,which uses both suspended and attached biomass,for the implementation of the anaerobic stage of the process,was compared with a sequencing batch reactor that only employs suspended biomass.The results showed that,although there was no meaningful difference in biomass concentration between the two bioreactors,the latter reactor had better performance in terms of chemical oxygen demand(COD)removal efficiency and rate and color removal rate.Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations,with the former yielding better color removal whilst the latter had better COD removal performance.The sequential anaerobic–aerobic process,employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1±7.9%and 79.9±1.5%,respectively.The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites,respectively.Also,aerobic partial mineralization of the dye reduction metabolites,was experimentally observed.
文摘Particle size analyzer,scanning electron microscope were used to investigate the dynamic membrane composition and filtration performance under optimal operation parameters.Energy dispersion spectroscopy was used to determine the elemental composition of the dynamic membrane.The results indicated that the mass concentration of cake layer was 39.27 g·m-2,with contents of colloid,volatile suspended solids and inorganic matter 5.75 g·m-2,26.5 g·m-2 and 7.02 g·m-2 respectively.Self-generated dynamic membrane mainly consisted of porous structure with high porosity.Filamentous bacteria which acted as matrix of dynamic membrane structure could be obviously observed.Most of the particle size range from 70μm to 130μm.O,K,Na,Ca,P,S,Cl,Mg,Si were the main elements in the dynamic membrane.
