反硝化型甲烷厌氧氧化微生物富集研究
发布时间：2019-06-05 19:47
【摘要】：反硝化型甲烷厌氧氧化(Denitrifying anaerobic methane oxidation,DAMO)能够在厌氧条件下,以甲烷作为电子供体,NO3-或NO2-作为电子受体,利用功能微生物的作用,将甲烷氧化为二氧化碳,硝态氮及亚硝态氮还原为氮气,为新型低物耗废水脱氮处理技术提供了新思路。但是由于参与该过程的功能微生物生长缓慢,富集培养困难,从而制约了其发展。本研究针对以上问题,开展了反硝化型甲烷厌氧氧化功能微生物的富集、影响因素及生物强化的分析研究,为解决反硝化型甲烷厌氧氧化技术的实际应用提供一定的理论基础。主要研究内容如下:1)构建一种全封闭、厌氧并连续曝甲烷的微孔曝气膜生物反应器,成功富集了该DAMO过程的主要功能微生物。活性检测结果表明该功能微生物对硝酸盐的平均去除速率约为0.56 mmol/d,对亚硝酸盐的平均去除速率约为0.83 mmol/d。通过13CH4稳定性同位素示踪技术定性的验证了富集培养物厌氧氧化甲烷的过程。同时厌氧间歇实验结果表明,甲烷和亚硝酸盐(硝酸盐)去除的化学计量数之比接近理论值3CH4:8NO2-(5CH4:8NO3-)。采用荧光原位杂交(FISH)技术、构建克隆文库、荧光定量PCR等技术分析NC10门细菌。克隆文库验证了三种富集培养物中反硝化型甲烷厌氧氧化功能细菌——NC10门细菌的存在。荧光原位杂交(FISH)结果显示随着富集时间的延长,NC10门细菌得到了加富,且在13个月后,NC10门细菌的相对丰度达到73%。荧光定量PCR结果初步表明,经过22个月的富集,每克干土样中NC10细菌的拷贝数在106左右。2)采用厌氧批式实验进行反硝化型甲烷厌氧氧化富集条件的分析,主要分析温度、培养液p H、基质浓度、甲烷分压等对反硝化型甲烷厌氧氧化功能微生物活性的影响。一般认为甲烷的溶解度是影响DAMO过程的最主要因素之一,而甲烷的溶解情况主要受气相中分压的影响。当甲烷分压低于49.72k Pa时,增加甲烷分压有利于提高DAMO微生物活性;但是当甲烷分压高于49.72k Pa时,甲烷的溶解度不再是DAMO微生物活性的限制因素。在本实验条件下,NO2-初始浓度、环境温度、培养液p H值分别在1.5mmol/L、25℃、7.48时,该DAMO功能微生物的活性最高。3)首次研究电场对反硝化型甲烷厌氧氧化功能微生物的刺激。外加不同强度的电压,考察0V、0.5V、1V、1.5V电压对DAMO功能微生物的刺激;改变加电方式,比较连续加电和间断加电作用的差异。研究显示电场可以强化该实验条件下DAMO功能微生物的活性。在连续施加1V电压时,该功能微生物的活性最强,说明对DAMO功能微生物性能起到促进作用的最佳电压为1V。但是间断施加1V的电压时,该DAMO功能微生物的活性却被抑制。
[Abstract]:Denitrifying methane (Denitrifying anaerobic methane oxidation,DAMO) can oxidize methane to carbon dioxide by using methane as electron donor and NO3- or NO2- as electron receptor under anaerobic conditions. Nitrate nitrogen and nitroso nitrogen are reduced to nitrogen, which provides a new idea for new nitrogen removal technology of low material consumption wastewater. However, the development of functional microorganisms is restricted by the slow growth of functional microorganisms and the difficulty of enrichment and culture. In order to solve the above problems, the enrichment, influencing factors and biological enhancement of denitrifying methane anaerobic oxidation functional microorganisms were analyzed and studied, which provided a certain theoretical basis for solving the practical application of denitrifying methane anaerobic oxidation technology. The main research contents are as follows: 1) A fully closed, anaerobic and continuous methane aeration membrane biofilm reactor was constructed, which successfully enriched the main functional microorganisms in the DAMO process. The results of activity test showed that the average removal rate of nitrate by this functional microorganism was about 0.56 mmol/d, and the average removal rate of nitrate was about 0.83 mmol/d.. The process of methane oxide enrichment by 13CH4 stable isotope tracer technique was qualitatively verified. At the same time, the results of anaerobic batch experiment show that the stoichiometric ratio of methane to nitrite (nitrate) removal is close to the theoretical value of 3CH4 鈮，
本文编号：2493778
[Abstract]:Denitrifying methane (Denitrifying anaerobic methane oxidation,DAMO) can oxidize methane to carbon dioxide by using methane as electron donor and NO3- or NO2- as electron receptor under anaerobic conditions. Nitrate nitrogen and nitroso nitrogen are reduced to nitrogen, which provides a new idea for new nitrogen removal technology of low material consumption wastewater. However, the development of functional microorganisms is restricted by the slow growth of functional microorganisms and the difficulty of enrichment and culture. In order to solve the above problems, the enrichment, influencing factors and biological enhancement of denitrifying methane anaerobic oxidation functional microorganisms were analyzed and studied, which provided a certain theoretical basis for solving the practical application of denitrifying methane anaerobic oxidation technology. The main research contents are as follows: 1) A fully closed, anaerobic and continuous methane aeration membrane biofilm reactor was constructed, which successfully enriched the main functional microorganisms in the DAMO process. The results of activity test showed that the average removal rate of nitrate by this functional microorganism was about 0.56 mmol/d, and the average removal rate of nitrate was about 0.83 mmol/d.. The process of methane oxide enrichment by 13CH4 stable isotope tracer technique was qualitatively verified. At the same time, the results of anaerobic batch experiment show that the stoichiometric ratio of methane to nitrite (nitrate) removal is close to the theoretical value of 3CH4 鈮，
本文编号：2493778
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