反硝化前置的序批式高浓度活性污泥法深度脱氮处理C/N偏低的市政污水
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摘要
市政污水C/N偏低增加深度脱氮难度与成本,不利于推动内陆缺水地区市政污水再生利用和地下水硝酸盐污染控制。采用铁氧化物促成的高浓度活性污泥,在反硝化前置的SBR中,不外加碳源和不调控pH的情况下处理C/N=4的模拟市政污水。结果表明:缺氧段前置反硝化脱氮进-步降低C/N,降低好氧曝气阶段的曝气需求;在曝气阶段,与单一高强度间隙曝气相比,先弱后强的间歇曝气利于降低异养好氧菌的作用及其对硝化细菌和反硝化细菌的不利影响,在C/N很低的情况下,仍能实现一定强度的硝化与反硝化协同脱氮,总体实现深度脱氮。在换水率为30%、40%和45%的情况下,先弱后强曝气模式下的脱氮效率分别为71.2%、72.4%和70.2%,均优于常规SBR,系统容积负荷分别为0.41、0.33、0.29 kg COD/(m~3·d),显著优于或与常规SBR相当,出水氨氮、总氮浓度均符合国家城镇污水排放一级A标准。
Low C/N in municipal wastewater normally increases operation difficulty and cost of high-efficiency nitrogen removal,hampers the reuse of treated wastewater and the control of groundwater nitrate pollution, especially in inland water-shortage areas. Performance of a pre-denitrification SBR with iron oxide-promoted high concentration activated sludge for high efficiency nitrogen removal from C/N=4 simulated municipal wastewater was investigated without the use of external carbon and pH regulation. Results showed that pre-denitrification coupled to COD removal in hypoxic stage further reduced C/N, reducing the requirement of aera tion in subsequent aeration stage. Compared with single-strong intensity intermittent aeration mode, two-intensity(first weak and then strong) intermittent aeration mode was more effective in limiting the role of heterotrophic aerobic bacteria and their suppressing effects on nitrifying and denitrifying bacteria in aeration stage. As a result, nitrification and denitrification-coupled nitrogen removal could happen to considerable extents, even at the further lowered C/N, overall achieving high efficiency nitrogen removal. At water exchange rates of 30%,40% and 45%,nitrogen removal efficiencies under two-intensity aeration mode were respectively71.2%, 72.4% and 70.2%, much better than that of conventional SBR. and volumetric loads of COD were respectively 0.41,0.33, 0.29 kg/(m3·d), much better than or equivalent to that of conventional SBR. The levels of ammonia nitrogen and total nitrogen in the effluent all met A-class national discharge standard of municipal sewage.
Low C/N in municipal wastewater normally increases operation difficulty and cost of high-efficiency nitrogen removal,hampers the reuse of treated wastewater and the control of groundwater nitrate pollution, especially in inland water-shortage areas. Performance of a pre-denitrification SBR with iron oxide-promoted high concentration activated sludge for high efficiency nitrogen removal from C/N=4 simulated municipal wastewater was investigated without the use of external carbon and pH regulation. Results showed that pre-denitrification coupled to COD removal in hypoxic stage further reduced C/N, reducing the requirement of aera tion in subsequent aeration stage. Compared with single-strong intensity intermittent aeration mode, two-intensity(first weak and then strong) intermittent aeration mode was more effective in limiting the role of heterotrophic aerobic bacteria and their suppressing effects on nitrifying and denitrifying bacteria in aeration stage. As a result, nitrification and denitrification-coupled nitrogen removal could happen to considerable extents, even at the further lowered C/N, overall achieving high efficiency nitrogen removal. At water exchange rates of 30%,40% and 45%,nitrogen removal efficiencies under two-intensity aeration mode were respectively71.2%, 72.4% and 70.2%, much better than that of conventional SBR. and volumetric loads of COD were respectively 0.41,0.33, 0.29 kg/(m3·d), much better than or equivalent to that of conventional SBR. The levels of ammonia nitrogen and total nitrogen in the effluent all met A-class national discharge standard of municipal sewage.
引文
[1]Majumdar D,Gupta N.Nitrate pollution of groundwater and associated human health disorders[J].Indian Journal of Environmental Health,2000,42(l):28-39.
[2]Bouchard D C,Williams M K,Rao Y S.Nitrate contamination of Lgroundwater:Sources and potential health effects[J].Journal,1992,84(9):85-90.
[3]Zhang W L,Tian Z X,Zhang N,et al.Nitrate pollution of groundwater in northern China[J].Agriculture Ecosystems&Environment,1996,59(3):223-231.
[4]张亚丽,张依章,张远,等.太子河流域地表水和地下水硝酸盐污染特征及来源分析[J].中国生态农业学报,2014,22(8):980-986.
[5]赵同科,张成军,杜连凤,等.环渤海七省(市)地下水硝酸盐含量调查[J].农业环境科学学报,2007.26(2):779-783.
[6]Chen J,Taniguchi M,Liu G,et al.Nitrate polltuiion of groundwater in the Yellow River delta,China[J].Hydrogeology Jourlnal,2007,15(8):1605-1614.
[7]丁强,王振兴.污水生物处理工艺强化脱氮除磷的研究进展[J].环境科技,2010,23(s1):89-92.
[8]刘兴平,郝晓美.城市污水处理工艺及其发展[J].水资源保护,2003,19(1):25-28.
[9]Yue Qiang,Zon X L,Miao Y Q.Development and application of SBR technology[J].Pollution Control Technology,2003,22(4):35-38.
[10]吴长航,金云霄,冯传平,等.SBBR处理不同C/N值城市污水的脱氮除磷性能[J].中国给水排水,2010,26(23):105-108.
[11]孙振世,柯强,陈英旭。SBR生物脱氮机理及其影响因素[J].中国沼气,2001,19(2):16-19.
[12]刘晓云。城市污水复合铁酶促活性污泥技术试验研究[D].青岛:青岛理工大学.2009.
[13]王绍超.复合铁酶促活性污泥强化污水生物脱氮除磷技术研究[D].青岛:青岛理工大学,2010.
[14]郭建华,彭永臻,杨庆,等,脉冲SBR处理城市污水深度脱氮的工艺特性[J].中国环境科学.2007,27(1),62.66.
[15]张杨,李庭刚,强志民等。膜曝气生物膜反应器研究进展[J].环境科学学报,2011,31(6):1133-1143.
[16]罗应东,濮文虹,杨昌柱,等.活性污泥颗粒化过程中理化性状及.脱氮性能的研究[J].环境科学,2011,32(1):212-216.
[17]赵永彬.城市污水处理厂SBR工艺脱氮调试与试验研究[D].大原:太原理工大学.2013.
[18]张婧倩,彭永臻,唐旭光,等.前置反硝化SBR工艺的设计[J].中国给水排水,2010,26(12):48-54.
[19]刘少武,周娇,张智.小城镇低负荷SBR工艺运行参数优化研究[J].给水排水,2009,35(9):39-42.
[20]胥驰.侧流除磷分段进水SBR工艺处理低碳源污水试验研究[D].重庆:重庆大学,2010.
[2]Bouchard D C,Williams M K,Rao Y S.Nitrate contamination of Lgroundwater:Sources and potential health effects[J].Journal,1992,84(9):85-90.
[3]Zhang W L,Tian Z X,Zhang N,et al.Nitrate pollution of groundwater in northern China[J].Agriculture Ecosystems&Environment,1996,59(3):223-231.
[4]张亚丽,张依章,张远,等.太子河流域地表水和地下水硝酸盐污染特征及来源分析[J].中国生态农业学报,2014,22(8):980-986.
[5]赵同科,张成军,杜连凤,等.环渤海七省(市)地下水硝酸盐含量调查[J].农业环境科学学报,2007.26(2):779-783.
[6]Chen J,Taniguchi M,Liu G,et al.Nitrate polltuiion of groundwater in the Yellow River delta,China[J].Hydrogeology Jourlnal,2007,15(8):1605-1614.
[7]丁强,王振兴.污水生物处理工艺强化脱氮除磷的研究进展[J].环境科技,2010,23(s1):89-92.
[8]刘兴平,郝晓美.城市污水处理工艺及其发展[J].水资源保护,2003,19(1):25-28.
[9]Yue Qiang,Zon X L,Miao Y Q.Development and application of SBR technology[J].Pollution Control Technology,2003,22(4):35-38.
[10]吴长航,金云霄,冯传平,等.SBBR处理不同C/N值城市污水的脱氮除磷性能[J].中国给水排水,2010,26(23):105-108.
[11]孙振世,柯强,陈英旭。SBR生物脱氮机理及其影响因素[J].中国沼气,2001,19(2):16-19.
[12]刘晓云。城市污水复合铁酶促活性污泥技术试验研究[D].青岛:青岛理工大学.2009.
[13]王绍超.复合铁酶促活性污泥强化污水生物脱氮除磷技术研究[D].青岛:青岛理工大学,2010.
[14]郭建华,彭永臻,杨庆,等,脉冲SBR处理城市污水深度脱氮的工艺特性[J].中国环境科学.2007,27(1),62.66.
[15]张杨,李庭刚,强志民等。膜曝气生物膜反应器研究进展[J].环境科学学报,2011,31(6):1133-1143.
[16]罗应东,濮文虹,杨昌柱,等.活性污泥颗粒化过程中理化性状及.脱氮性能的研究[J].环境科学,2011,32(1):212-216.
[17]赵永彬.城市污水处理厂SBR工艺脱氮调试与试验研究[D].大原:太原理工大学.2013.
[18]张婧倩,彭永臻,唐旭光,等.前置反硝化SBR工艺的设计[J].中国给水排水,2010,26(12):48-54.
[19]刘少武,周娇,张智.小城镇低负荷SBR工艺运行参数优化研究[J].给水排水,2009,35(9):39-42.
[20]胥驰.侧流除磷分段进水SBR工艺处理低碳源污水试验研究[D].重庆:重庆大学,2010.