海绵铁缓解污水厌氧氨氧化反应器中硝酸盐积累的效果
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摘要
该文旨在通过向厌氧氨氧化反应器中投加海绵铁来减轻厌氧SBR(sequencingbatchreactoractivatedsludge process)反应器中的硝酸盐积累,试验研究了海绵铁与硝酸盐和亚硝酸盐在静态条件下的反应。在静态条件下,部分硝酸盐和亚硝酸盐被海绵铁还原成了氨。对比动态试验表明投加海绵铁可以将SBR出水硝酸盐质量浓度控制在25～30 mg/L左右。相同条件下不投加海绵铁出水硝酸盐质量浓度不断累积,直至超过55 mg/L。这可能是由于铁将硝酸盐还原为亚硝酸盐并与厌氧氨氧化进行了耦合。采用高通量测序发现投加海绵铁的反应器中厌氧氨氧化菌在微生物群落中所占的比例(22.55%)约为不投加反应器(8.85%)的3倍,表明投加海绵铁有利于反应器中厌氧氨氧化(ANAMMOX)菌的生长和厌氧氨氧化反应器的启动。
Anaerobic ammonia oxidation(ANAMMOX) is a process in which ammonia, as the electron donor, is oxidized by nitrite. Nitrate is accumulated as the main production in addition to N2 in the solution, causing incomplete removal of total nitrogen in water. Some processes, such as oxic denitrification, anaerobic denitrification or dozing of chemicals, can be used to achieve partial denitrification(reduction of nitrate to nitrite). The reduction of nitrate to nitrite can couple with ANAMMOX process, achieving complete removal of nitrogen. In this paper, sponge iron was added into an ANAMMOX sequencing batch reactor(SBR) to decrease nitrate accumulation. Sponge iron is a kind of special zero-valence iron(ZVI) which has a larger specific surface than that of the normal scrap iron, and is cheaper than nano-ZVI. The sponge iron can react with oxidants, such as oxygen and nitrate, immediately in solution and produce Fe2+ or Fe3+. The reactions between sponge iron with nitrite and nitrate were studied in a static state, in which the nitrite and nitrate were reduced into ammonia by sponge iron in solutions. Several factors affecting the reactions between sponge iron with nitrite and nitrate were investigated, such as the dose and particle size of sponge iron, solution pH value and dissolved oxygen(DO). The results showed that small sponge iron particle size and high DO concentration were favorable for nitrite and nitrate removal. Low solution pH value had slight enhancement in nitrate and nitrite removal. In the dynamic experiments, two ANAMMOX SBRs(marked as A and B, both with an effective volume of 2 L) acclimatized with the municipal wastewater plant anaerobic sludge were operated about 20 days, then the reactor B was added with 300 g sponge iron with diameter of 5-8 mm, and the reactor A was used as control. The nitrate concentration in the outlet of reactor B dosed with sponge iron could be kept around 25-30 mg/L, while in reactor A without sponge iron, it could reach 55 mg/L, solving the problem of large quantity of nitrate accumulation. In the reactor A without sponge iron, the nitrate concentration was increasing, showing obvious nitrate accumulation. The mitigation of nitrate may come from the reaction of iron with nitrate, providing the reducing product nitrite to couple with ANAMMOX. Obvious red granule sludge could be seen in the reactor with sponge iron, which suggested that the ferric and ferrous ions may be beneficial for the production of granule sludge. High-throughput sequencing showed that the proportion of ANAMMOX bacteria in the SBR with sponge iron(22.55%) was three times of that(8.85%) in the SBR without sponge iron, proving that the sponge iron was favorable for the start-up of the ANAMMOX SBR. Also the ferric and ferrous ions produced from oxidation of sponge iron by nitrate may also provide necessary element demand of the microorganisms, for example, the ANAMMOX bacteria.
Anaerobic ammonia oxidation(ANAMMOX) is a process in which ammonia, as the electron donor, is oxidized by nitrite. Nitrate is accumulated as the main production in addition to N2 in the solution, causing incomplete removal of total nitrogen in water. Some processes, such as oxic denitrification, anaerobic denitrification or dozing of chemicals, can be used to achieve partial denitrification(reduction of nitrate to nitrite). The reduction of nitrate to nitrite can couple with ANAMMOX process, achieving complete removal of nitrogen. In this paper, sponge iron was added into an ANAMMOX sequencing batch reactor(SBR) to decrease nitrate accumulation. Sponge iron is a kind of special zero-valence iron(ZVI) which has a larger specific surface than that of the normal scrap iron, and is cheaper than nano-ZVI. The sponge iron can react with oxidants, such as oxygen and nitrate, immediately in solution and produce Fe2+ or Fe3+. The reactions between sponge iron with nitrite and nitrate were studied in a static state, in which the nitrite and nitrate were reduced into ammonia by sponge iron in solutions. Several factors affecting the reactions between sponge iron with nitrite and nitrate were investigated, such as the dose and particle size of sponge iron, solution pH value and dissolved oxygen(DO). The results showed that small sponge iron particle size and high DO concentration were favorable for nitrite and nitrate removal. Low solution pH value had slight enhancement in nitrate and nitrite removal. In the dynamic experiments, two ANAMMOX SBRs(marked as A and B, both with an effective volume of 2 L) acclimatized with the municipal wastewater plant anaerobic sludge were operated about 20 days, then the reactor B was added with 300 g sponge iron with diameter of 5-8 mm, and the reactor A was used as control. The nitrate concentration in the outlet of reactor B dosed with sponge iron could be kept around 25-30 mg/L, while in reactor A without sponge iron, it could reach 55 mg/L, solving the problem of large quantity of nitrate accumulation. In the reactor A without sponge iron, the nitrate concentration was increasing, showing obvious nitrate accumulation. The mitigation of nitrate may come from the reaction of iron with nitrate, providing the reducing product nitrite to couple with ANAMMOX. Obvious red granule sludge could be seen in the reactor with sponge iron, which suggested that the ferric and ferrous ions may be beneficial for the production of granule sludge. High-throughput sequencing showed that the proportion of ANAMMOX bacteria in the SBR with sponge iron(22.55%) was three times of that(8.85%) in the SBR without sponge iron, proving that the sponge iron was favorable for the start-up of the ANAMMOX SBR. Also the ferric and ferrous ions produced from oxidation of sponge iron by nitrate may also provide necessary element demand of the microorganisms, for example, the ANAMMOX bacteria.
引文
[1]Kumar M,Lin J G.Co-existence of anammox and denitrification for simultaneous nitrogen and carbon removal-strategies and issues[J].Journal of Hazardous Materials,2010,178:1-3.
[2]Chen X,Guo J,Xie G J,et al.A new approach to simultaneous ammonium and dissolved methane removal from anaerobic digestion liquor:A model-based investigation of feasibility[J].Water Research,2015,85:295-303.
[3]Du R,Peng Y,Cao S,et al.Advanced nitrogen removal with simultaneous anammox and denitrification in sequencing batch reactor[J].Bioresource Technology,2014,162(6):316-322.
[4]Miao Y,Liang Z,Yang Y,et al.Start-up of single-stage partial nitrification-anammox process treating low-strength swage and its restoration from nitrate accumulation[J].Bioresource Technology,2016,218:771-779.
[5]Schipper L A,Vojvodic′Vukovic′M.Nitrate removal from groundwater and denitrification rates in a porous treatment wall amended with sawdust[J].Ecological Engineering,2000,14(3):269-278.
[6]周健,完颜德卿,黄勇,等.ANAMMOX菌利用零价铁还原硝酸盐脱氮研究[J].环境科学,2016,37(11):4302-4308.Zhou Jian,Wanyan Deqing,Huang Yong,et al.Biotransformation of nitrate to nitrogen gas driven by ANAMMOX microbes via zero-valent iron under anaerobic conditions[J].Environment Science,2016,37(11):4302-4308.(in Chinese with English abstract)
[7]林龙利,刘国光,杨敏建,等.零价铁在水污染治理中的应用研究进展[J].工业水处理,2016,36(3):6-10.Lin Longli,Liu Guoguang,Yang Minjian,et al.Research progress in the application of Fe0 to water pollution control[J].Industrial Water Treatment,2016,36(3):6-10.(in Chinese with English abstract)
[8]Zhang Y,Douglas G B,Pu L,et al.Zero-valent iron-facilitated reduction of nitrate:Chemical kinetics and reaction pathways[J].Science of the Total Environment,2017,598:1140-1150.
[9]Jie X,Yuan P,Qi W K,et al.Chemical removal of nitrate from water by aluminum-iron alloys[J].Chemosphere,2017,166:197-202.
[10]杨世东,廖路花.进水配比对煤气化废水厌氧段处理效能影响[J].硅酸盐通报,2016,35(2):392-398.Yang Shidong,Liao Luhua.Effect of influent ratio on anaerobic treatment of coal gasification wastewater[J].Bulletin of the Chniese Ceramic Society,2016,35(2):392-398.(in Chinese with English abstract)
[11]国家环保总局.水和废水监测分析方法[M].第四版.北京:中国环境科学出版社,2002.
[12]刘琰,李剑超,赵英花,等.海绵铁转化地下水中硝酸盐的试验研究[J].环境污染与防治,2012,34(11):20-24.Liu Yan,Li Jianchao,Zhao Yinghua,et al.Research on the conversion of nitrate in groundwater with sponge iron[J].Environmental Pollution&Control,2012,34(11):20-24.(in Chinese with English abstract)
[13]邓妮.厌氧氨氧化反应器的启动与运行特性研究[D].无锡:江南大学,2012.
[14]周少奇,姚俊芹.UASB厌氧氨氧化反应器启动研究[J].食品与生物技术学报,2005,24(6):1-5.Zhou Shaoqi,Yao Junqin.Start up of anaerobic ammonium oxidation reaction in UASB bioreactor[J].Journal of Food Science and Biotechnology,2005,24(6):1-5.(in Chinese with English abstract)
[15]Speth D R,Hu B,Bosch N,et al.Comparative genomics of two independently enriched“Candidatus Kuenenia Stuttgartiensis”anammox bacteria[J].Frontiers in Microbiology,2012,3:307.
[16]Oshiki M,Ali M,Shinyako-Hata K,et al.Hydroxylaminedependent anaerobic ammonium oxidation(anammox)by“Candidatus Brocadia sinica”[J].Environmental Microbiology,2016,18(9):3133-3143.
[17]Ruangchainikom C,Liao C H,Anotai J,et al.Characteristics of nitrate reduction by zero-valent iron powder in the recirculated and CO2-bubbled system[J].Water Research,2006,40(2):195-204.
[18]李铁龙,孙丽莉,金朝晖,等.纳米铁系双金属复合材料还原水中硝酸盐氮[J].吉林大学学报:工学版,2009,39(2):84-89.Li Tielong,Sun Lili,Jin Zhaohui,et al.Nitrate reduction in water by iron-system bimetallic nanoparticles[J].Journal of Jilin University:Engineering and Technology Edition,2009,39(2):84-89.(in Chinese with English abstract)
[19]Lenell B A,Arai Y.Perrhenate sorption kinetics in zerovalent iron in high pH and nitrate media[J].Journal of Hazardous Materials,2017,321:335-343.
[20]冯艳平,李俊国,毕娜,等.球形海绵铁还原去除水中硝酸盐的静态研究[J].环境科学与技术,2008,31(6):14-18.Feng Yanping,Li Junguo,Bi Na,et al.Experimental study of nitrate removal from water by spherical sponge iron[J].Environmental Science&Technology,2008,31(6):14-18.(in Chinese with English abstract)
[21]Zhang Z Z,Xu J J,Shi Z J,et al.Unraveling the impact of nanoscale zero-valent iron on the nitrogen removal performance and microbial community of anammox sludge[J].Bioresource Technology,2017,243:883-892.
[22]Fan G,Zhang H,Yang F,et al.The effects of zero-valent iron(ZVI)and ferroferric oxide(Fe3O4)on anammox activity and granulation in anaerobic continuously stirred tank reactors(CSTR)[J].Process Biochemistry,2014,49(11):1970-1978.
[2]Chen X,Guo J,Xie G J,et al.A new approach to simultaneous ammonium and dissolved methane removal from anaerobic digestion liquor:A model-based investigation of feasibility[J].Water Research,2015,85:295-303.
[3]Du R,Peng Y,Cao S,et al.Advanced nitrogen removal with simultaneous anammox and denitrification in sequencing batch reactor[J].Bioresource Technology,2014,162(6):316-322.
[4]Miao Y,Liang Z,Yang Y,et al.Start-up of single-stage partial nitrification-anammox process treating low-strength swage and its restoration from nitrate accumulation[J].Bioresource Technology,2016,218:771-779.
[5]Schipper L A,Vojvodic′Vukovic′M.Nitrate removal from groundwater and denitrification rates in a porous treatment wall amended with sawdust[J].Ecological Engineering,2000,14(3):269-278.
[6]周健,完颜德卿,黄勇,等.ANAMMOX菌利用零价铁还原硝酸盐脱氮研究[J].环境科学,2016,37(11):4302-4308.Zhou Jian,Wanyan Deqing,Huang Yong,et al.Biotransformation of nitrate to nitrogen gas driven by ANAMMOX microbes via zero-valent iron under anaerobic conditions[J].Environment Science,2016,37(11):4302-4308.(in Chinese with English abstract)
[7]林龙利,刘国光,杨敏建,等.零价铁在水污染治理中的应用研究进展[J].工业水处理,2016,36(3):6-10.Lin Longli,Liu Guoguang,Yang Minjian,et al.Research progress in the application of Fe0 to water pollution control[J].Industrial Water Treatment,2016,36(3):6-10.(in Chinese with English abstract)
[8]Zhang Y,Douglas G B,Pu L,et al.Zero-valent iron-facilitated reduction of nitrate:Chemical kinetics and reaction pathways[J].Science of the Total Environment,2017,598:1140-1150.
[9]Jie X,Yuan P,Qi W K,et al.Chemical removal of nitrate from water by aluminum-iron alloys[J].Chemosphere,2017,166:197-202.
[10]杨世东,廖路花.进水配比对煤气化废水厌氧段处理效能影响[J].硅酸盐通报,2016,35(2):392-398.Yang Shidong,Liao Luhua.Effect of influent ratio on anaerobic treatment of coal gasification wastewater[J].Bulletin of the Chniese Ceramic Society,2016,35(2):392-398.(in Chinese with English abstract)
[11]国家环保总局.水和废水监测分析方法[M].第四版.北京:中国环境科学出版社,2002.
[12]刘琰,李剑超,赵英花,等.海绵铁转化地下水中硝酸盐的试验研究[J].环境污染与防治,2012,34(11):20-24.Liu Yan,Li Jianchao,Zhao Yinghua,et al.Research on the conversion of nitrate in groundwater with sponge iron[J].Environmental Pollution&Control,2012,34(11):20-24.(in Chinese with English abstract)
[13]邓妮.厌氧氨氧化反应器的启动与运行特性研究[D].无锡:江南大学,2012.
[14]周少奇,姚俊芹.UASB厌氧氨氧化反应器启动研究[J].食品与生物技术学报,2005,24(6):1-5.Zhou Shaoqi,Yao Junqin.Start up of anaerobic ammonium oxidation reaction in UASB bioreactor[J].Journal of Food Science and Biotechnology,2005,24(6):1-5.(in Chinese with English abstract)
[15]Speth D R,Hu B,Bosch N,et al.Comparative genomics of two independently enriched“Candidatus Kuenenia Stuttgartiensis”anammox bacteria[J].Frontiers in Microbiology,2012,3:307.
[16]Oshiki M,Ali M,Shinyako-Hata K,et al.Hydroxylaminedependent anaerobic ammonium oxidation(anammox)by“Candidatus Brocadia sinica”[J].Environmental Microbiology,2016,18(9):3133-3143.
[17]Ruangchainikom C,Liao C H,Anotai J,et al.Characteristics of nitrate reduction by zero-valent iron powder in the recirculated and CO2-bubbled system[J].Water Research,2006,40(2):195-204.
[18]李铁龙,孙丽莉,金朝晖,等.纳米铁系双金属复合材料还原水中硝酸盐氮[J].吉林大学学报:工学版,2009,39(2):84-89.Li Tielong,Sun Lili,Jin Zhaohui,et al.Nitrate reduction in water by iron-system bimetallic nanoparticles[J].Journal of Jilin University:Engineering and Technology Edition,2009,39(2):84-89.(in Chinese with English abstract)
[19]Lenell B A,Arai Y.Perrhenate sorption kinetics in zerovalent iron in high pH and nitrate media[J].Journal of Hazardous Materials,2017,321:335-343.
[20]冯艳平,李俊国,毕娜,等.球形海绵铁还原去除水中硝酸盐的静态研究[J].环境科学与技术,2008,31(6):14-18.Feng Yanping,Li Junguo,Bi Na,et al.Experimental study of nitrate removal from water by spherical sponge iron[J].Environmental Science&Technology,2008,31(6):14-18.(in Chinese with English abstract)
[21]Zhang Z Z,Xu J J,Shi Z J,et al.Unraveling the impact of nanoscale zero-valent iron on the nitrogen removal performance and microbial community of anammox sludge[J].Bioresource Technology,2017,243:883-892.
[22]Fan G,Zhang H,Yang F,et al.The effects of zero-valent iron(ZVI)and ferroferric oxide(Fe3O4)on anammox activity and granulation in anaerobic continuously stirred tank reactors(CSTR)[J].Process Biochemistry,2014,49(11):1970-1978.