Anammox培养物对氨与硫酸盐同步转化机制的研究

发布时间：2018-05-17 14:35

本文选题：厌氧氨氧化 + 硫酸盐还原氨氧化　；参考：《苏州科技大学》2017年硕士论文

【摘要】：NH_4~+与SO_4~(2-)在接种ANAMMOX培养物的无机条件下发生同步转化的现象(SRAO)得到研究者的关注,并据此认为这是发生了以SO_4~(2-)为电子受体的NH_4~+氧化过程。然而从相关文献报道可以看出,?N/?S普遍高于理论推测值、NH_4~+与SO_4~(2-)存在独立转化现象、不同研究者之间所观察到的实验现象存在明显区别等,这些问题和疑惑的阻碍了本课题的进一步深入研究。所以,根据目前所存在的疑问以及需要解决的问题,本文研究了以下三方面的内容:(1)在严格厌氧环境下NH_4~+与SO_4~(2-)能否发生反应;(2)厌氧环境中观察到的NH_4~+与SO_4~(2-)同步转化是否为两者之间发生的反应;(3)NH_4~+与SO_4~(2-)同步消耗的转化机制。在无机环境下,接种Anammox培养物,采用CFSTR及Batch的方式进行实验研究,得出以下结论:1)在无机厌氧环境条件下(ORP㧟300 mV±10 mV),NH_4~+与SO_4~(2-)可以发生同步转化。?N/?S普遍高于理论推测值,得失电子不平衡,说明系统中有外源电子参与反应;Batch 1实验中NH_4~+与SO_4~(2-)整体上都有转化,但各阶段中两者并不保持同步,说明NH_4~+与SO_4~(2-)的转化并不一定是两者之间的反应;在无SO_4~(2-)存在的厌氧条件下,NH_4~+同样可以发生转化,说明NH_4~+的转化与SO_4~(2-)并没有直接的关系。2)严格厌氧环境下(ORP为㧟490 mV±5 mV),NH_4~+不发生转化,而SO_4~(2-)会单独进行转化,说明SO_4~(2-)厌氧还原的电子供体并不是NH_4~+。总之,实验中所观察到的NH_4~+与SO_4~(2-)同步转化现象是两者各自独立转化的结果。另外,通过本文研究得到的结论对各研究者文献资料的深入分析,从其?N/?S普遍高于理论值反映有外源电子受体进入到系统、NH_4~+在常规Anammox阶段的过量转化与SRAO过程的独立转化现象、启动时间及转化速率倍增时间、热力学方面的分析论证等方面证明:文献中所观察到的NH_4~+与SO_4~(2-)同步转化也可能并不是两者之间进行的反应。结合本文研究及文献分析推测:本实验及相关文献中SRAO过程转化的NH_4~+主要是被O2及其氧化产物NO2-所氧化,SRAO过程中消耗的SO_4~(2-)主要是被微生物衰亡释放的有机物进行的异养还原;同时,NH_4~+的氧化产物NO2-/NO_3~-还可能会与SO_4~(2-)的还原产物S2-进行硫自养反硝化反应生成S0/含硫胶体/SO_4~(2-)。并且,文献资料分析及理论计算证明,本文所推测的基质转化机制与实际实验现象相符合,可以很好的解释各研究者实验中存在的问题和疑惑。
[Abstract]:The phenomenon of simultaneous transformation of NH4- and SO4- (2) in inorganic condition inoculated with ANAMMOX culture (SRAO) has attracted the attention of researchers, and it is considered that this is a process of NH4- oxidation in which so _ 4 / C _ (2-) is an electronic receptor. However, it can be seen from the relevant literature reports that there is a phenomenon of independent transformation of N- / S generally higher than that of theoretical conjecture, and there are obvious differences between the experimental phenomena observed by different researchers and so on. These questions and doubts hinder the further study of this subject. So, based on the existing questions and the problems that need to be solved, In this paper, we have studied the following three aspects: 1) whether there is a reaction between NH _ 4 ~ and so _ 4 / T _ 2 in a strict anaerobic environment?) whether the simultaneous conversion of NH _ 4 ~ and so _ 4 ~ is observed in the anaerobic environment as a reaction between them, and whether the simultaneous conversion of NH _ 4 ~ and so _ 4 ~ + is a mechanism of simultaneous consumption of NH _ 4 ~ and so _ 4 ~. In inorganic environment, inoculated with Anammox culture and studied by CFSTR and Batch, the following conclusions are drawn: (1) in inorganic anaerobic environment, ORP (300mV 卤10mV) NH4- and SO4- (2-) can occur synchronous transformation. The imbalance of gain and loss of electrons indicates that there are exogenous electrons involved in the reaction of Batch _ 1 experiment. In the experiment of Batch _ 1, NH4- and SO4- (2) are transformed as a whole, but they are not kept in sync in each stage, which means that the transformation of NH4- and SO4- (2) is not necessarily a reaction between the two. Under the anaerobic condition of no so _ 4 ~), NH4~ can also be transformed, indicating that the conversion of NH _ 4~ is not directly related to so _ 4 ~). (2) under the strict anaerobic environment, the ORP is 490mV 卤5mV ~ V / NH _ 4T ~ and no conversion takes place, while the so _ 4s _ 4 ~ + _ 2) will be transformed alone. The results show that the electron donor for anaerobic reduction is not NH _ 4 ~. In a word, the phenomenon of NH4- and SO4-) synchronous transformation observed in the experiment is the result of their independent transformation. In addition, based on the conclusion of this paper, through the in-depth analysis of the literature data of various researchers, it is found that the N / P S generally higher than the theoretical value reflects the phenomenon of excessive transformation of exogenous electron receptors entering into the system of NH _ 4 ~ and independent transformation of SRAO process in the routine Anammox stage. The start-up time and the doubling time of conversion rate, thermodynamic analysis and demonstration prove that the synchronous transformation of NH4 ~ and SO4 / 2) observed in the literature may not be the reaction between them. Combined with this study and literature analysis, it can be inferred that the NH4 ~ of SRAO transformed by SRAO in this experiment and related literature is mainly the heterotrophic reduction of organic matter released by microorganism, which is consumed in the process of oxidizing SRAO by O _ 2 and its oxidation product no ~ (-). At the same time, no _ 2-/ no _ 3s, the oxidation product of NH _ 4 ~, and probably S _ 2-, the reducing product of S _ 2-, were produced by sulfur autotrophic denitrification to form S _ 0 / S _ 4 / S _ 4 / S _ 4 / S _ 2. Moreover, the literature analysis and theoretical calculation prove that the mechanism of matrix transformation in this paper is consistent with the actual experimental phenomenon, which can explain the problems and doubts in the experiments of various researchers.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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