近年来,一些研究发现 Anammox 微生物可以利用 NO3 -、SO4 2-、Fe3+和锰氧化物 等作为电子受体,也可以利用 Fe2+或不同的基酸(包括甲酸、乙酸和丙酸)作为电子 供体,对不同电子受体的研究具有重要的科学意义和应用价值。本研究在无机厌氧环 境下,以 Anammox 微生物为接种物,采用厌氧循环流反应器进行不同电子受体的深 入研究。通过为期一年多的实验发现,在近中性条件下,分别以 NO3 -、SO4 2-、HCO3 - 为电子受体,以氨氮为电子供体,发现氮损失与 HCO3 -有密切的关系。进一步对厌氧 碳酸氢盐还原-氨氧化的可行性进行验证,研究 HCO3 -和 NH4 +的同步生物去除特性, 并对反应体系中可能的反应机理进行了推测,得出以下结论: (1)在循环流反应器中,进水电子受体为 NO3 -、SO4 2-、HCO3 -时,对 NH4 +-N 的平均转化速率分别达到了 328.1mg.(L.d)-1、415.7mg.(L.d)-1和 434.3mg.(L.d)-1;然 而,电子受体 SO4 2-或 NO3 -基本未去除,表明在该体系下电子受体 SO4 2-或 NO3 -并未 氧化 NH4 +,推测 HCO3 -作为电子受体氧化了氨。 (2)通过化学反应实验和生物反应实验证明,NH4 +和 HCO3 -之间发生的是生物 反应。 (3)碱度的形式对氨氮的转化速率有显著的影响,当进水 HCO3 -浓度不足时, 氨氮的转化速率有明显的下降,表明其中起着关键作用的是 HCO3 -。通过进水不同 HCO3 --C/NH4 +-N 摩尔比的批试实验证明,氨氮转化速率与进水 HCO3 --C/NH4 +-N 摩尔 比有关,要使反应顺利进行进水 HCO3 --C/NH4 +-N 摩尔比应≥1.14。 (4)在循环流反应器中,NH4 +-N 和 HCO3 --C 平均去除速率最大分别达到了 514.6 mg.(L.d)-1和 504.9 mg.(L.d)-1,HCO3 --C/NH4 +-N 摩尔转化比基本能稳定在 1.14 左右。 (5)循环流反应体系中发生的反应机理是由两个阶段三个基本反应组成。第一 阶段为两个平行反应,即 NH4 +和 HCO3 -发生氧化还原反应生成 NO3 -,同时,NH4 +和 HCO3 -发生氧化还原反应生成中间产物 NO2 -;第二阶段,生成的 NO2 -又与原反应物 中的 NH4 +发生传统的 Anammox 反应生成 N2 。 关键词:厌氧氨氧化;电子受体;HCO3 -;HCO3 --C/NH4 +-N 摩尔转化比;反应机理; II ABSTRACT Recently years, several studies found that anammox microorganism could use NO3 -、 SO4 2-、Fe3+and manganic oxide as electron acceptor, also could use Fe2+and different acids (formic acid, acetic acid and propionic acid) as electron donor. The study of different electron acceptors has important scientific significance and application value. Research of different electron acceptors (NO3 -、SO4 2-、HCO3 -) was carried out in an anaerobic circulating fluidization reactor in which Anammox microorganism acted as an inoculum in an inorganic anaerobic environment.Through a period of more than a year the experiment results showed that nitrogen loss was bound up with HCO3 -. The verification of anaerobic bicarbonate-reducing ammonia oxidation reaction was made in this study, and the synchronized removal biologic characteristics of HCO3 -and NH4 +also be studied, finally the possible reaction mechanism was speculated. The main research results were shown as follows: (1) In the circulation fluidization reactor, when the influent electron acceptor is NO3 -、 SO4 2-、HCO3 -, the average conversion rate of NH4 +-N reached 328.1mg·(L·d)-1、415.7 mg·(L·d)-1and 434.3mg·(L·d)-1respectively. however, the electron acceptor SO4 2-or NO3 - was not removed, indicating that the system of SO4 2-or NO3 -electron acceptor was not oxidized NH4 +, revealing that HCO3 -was electron acceptor for the oxidation of ammonia. (2) Biological reaction was achieved between NH4 +-N and HCO3 --C based on the results of chemical reaction experiments and biological reaction experiments. (3) The form of alkalinity had no significant effect on the conversion rate of ammonia, when the concentration of HCO3 -was insufficient, the conversion rate of ammonia nitrogen significantly decreased, indicating that HCO3 -played a key role. The ammonia nitrogen conversion rate was related to the HCO3 --C/NH4 +-N ratio in different HCO3 --C/NH4 +-N molar ratio of water inflow, and HCO3 --C/NH4 +-N ratio should be greater than or equal to 1.14 to make the reaction smoothly. (4) In the circulation fluidization reactor, the average removal rates of HCO3 --C and NH4 +-N reached 514.6 mg·(L·d)-1and 504.9 mg·(L·d)-1, respectively, HCO3 --C/NH4 +-N molar conversion ratio stably kept in 1.14. (5) Reaction mechanism was composed of two stages and three basic reactions in the circulation fluidization reaction system. The first stage was two parallel reactions, namely redox reaction of NH4 +and HCO3 -to NO3 -, at the same time, and NH4 +and HCO3 - III simultaneously produced intermediate NO2 -. The second stage was traditional anammox reaction of the generated NO2 -and NH4 +to N2 . Keywords: Anaerobic ammonium oxidation;electronic acceptor; HCO3 -; HCO3 --C/NH4 +-N molar conversion ratio; reaction mechanism; i 目录 摘要..........................................................................................................................................................I ABSTRACT.............................................................................................................................................II 目录............................................................................................................................................................i 第一章 绪论 .............................................................................................................................................1 1.1 含氮污染物的来源 .................................................................................................................... 1 1.1.1 无机氮污染....................................................................................................................... 2 1.1.2 有机氮污染....................................................................................................................... 3 1.2 含氮污染物质的危害 ................................................................................................................ 3 1.2.1 刺激或促进水体中植物和藻类的生长........................................................................... 4 1.2.2 消耗水体中的溶解氧....................................................................................................... 4 1.2.3 影响人类健康.................................................................................................................. 4 1.2.4 对人类经济的影响.......................................................................................................... 5 1.3 生物脱氮技术的研究进展 ........................................................................................................ 5 1.3.1 传统的生物脱氮技术....................................................................................................... 5 1.3.2 短程硝化-反硝化技术 ..................................................................................................... 6 1.3.3 厌氧氨氧化的发现及其组合工艺................................................................................... 7 1.4 Anammox 微生物的基质多样性 ............................................................................................. 11 1.4.1 以硫酸盐作为电子受体的研究..................................................................................... 11 1.4.2 利用 Fe3+作为电子受体.................................................................................................13 1.4.3 利用有机酸作为电子供体............................................................................................. 13 1.5 本课题的研究目的和意义、内容与创新点............................................................................ 15 1.5.1 研究的目的和意义......................................................................................................... 15 1.5.2 研究内容......................................................................................................................... 16 1.5.3 创新点 ............................................................................................................................ 16 第二章 实验装置、材料与方法 ...........................................................................................................17 2.1 实验装置 .................................................................................................................................. 17 2.2 接种污泥与模拟废水 .............................................................................................................. 17 2.2.1 接种污泥........................................................................................................................ 17 2.2.2 模拟废水........................................................................................................................ 17 2.3 实验研究方法 ........................................................................................................................... 18 2.4 分析测定项目及方法 .............................................................................................................. 20 2.5 实验设备 .................................................................................................................................. 20 第三章 不同电子受体氧化氨的可行性研究 .......................................................................................21 3.1 不同电子受体氧化氨的运行结果与分析............................................................................... 21 3.1.1 NH4 +和 NO3 -反应体系中的运行结果与分析...............................................................21 3.1.2 NH4 +和 SO4 2-反应体系中的运行结果与分析...............................................................23 3.1.3 NH4 +和 HCO3 -反应体系中的运行结果与分析.............................................................24 3.2 不同电子受体情况下碱度变化情况分析............................................................................... 24 3.3 不同电子受体情况下各物质的转化特性............................................................................... 25 3.4 小结 ........................................................................................................................................... 28 第四章 氨与碳酸氢盐反应控制条件的研究 .......................................................................................29 ii 4.1 HCO3 -浓度变化对氨转化的运行结果与分析........................................................................29 4.1.1 HCO3 -浓度变化对脱氮效能的影响分析......................................................................30 4.1.2 HCO3 -在体系中的作用机理分析..................................................................................31 4.2 不同碱度形式对氨转化的影响 .............................................................................................. 32 4.3 不同 C/N 摩尔比下的批试实验.............................................................................................. 33 4.3.1 C/N 摩尔比为 2.4:1 时反应器运行性能 ....................................................................... 33 4.3.2 C/N 摩尔比为 1.3:1 时反应器运行性能 ....................................................................... 34 4.3.3 C/N 摩尔比为 0.8:1 时反应器运行性能 ....................................................................... 35 4.3.4 不同 C/N 摩尔比下各物质转化特性分析 ................................................................... 36 4.4 小结 ........................................................................................................................................... 37 第五章 厌氧碳酸氢盐还原氨氧化的反应机理分析 ...........................................................................38 5.1 循环流体系中氨转化的途径分析 ........................................................................................... 38 5.1.1 化学反应实验................................................................................................................. 39 5.1.2 生物反应实验................................................................................................................. 40 5.2 循环流体系中 HCO3 -转化途径分析.......................................................................................41 5.2.1 物理化学作用转化 HCO3 -的可能性.............................................................................41 5.2.2 Anammox 途径转化 HCO3 -的可能性 ...........................................................................41 5.3 氨和碳酸氢盐同步转化特性分析 ........................................................................................... 42 5.3.1 氨氮的氧化产物............................................................................................................. 43 5.3.2 pH 值变化....................................................................................................................... 45 5.3.3 反应底物转化比............................................................................................................. 45 5.4 反应机理分析与验证 .............................................................................................................. 46 5.4.1 反应机理一的验证........................................................................................................ 48 5.4.2 反应机理二的验证........................................................................................................ 49 5.4.3 反应机理三的验证........................................................................................................ 50 第六章 结论与建议 ...............................................................................................................................53 6.1 结论 .......................................................................................................................................... 53 6.2 建议 .......................................................................................................................................... 53