【摘要】：反硝化型甲烷厭氧氧化(Denitrifying anaerobic methane oxidation,DAMO)能夠在厭氧條件下,以甲烷作為電子供體,NO3-或NO2-作為電子受體,利用功能微生物的作用,將甲烷氧化為二氧化碳,硝態(tài)氮及亞硝態(tài)氮還原為氮氣,為新型低物耗廢水脫氮處理技術(shù)提供了新思路。但是由于參與該過程的功能微生物生長緩慢,富集培養(yǎng)困難,從而制約了其發(fā)展。本研究針對以上問題,開展了反硝化型甲烷厭氧氧化功能微生物的富集、影響因素及生物強化的分析研究,為解決反硝化型甲烷厭氧氧化技術(shù)的實際應用提供一定的理論基礎。主要研究內(nèi)容如下:1)構(gòu)建一種全封閉、厭氧并連續(xù)曝甲烷的微孔曝氣膜生物反應器,成功富集了該DAMO過程的主要功能微生物�；钚詸z測結(jié)果表明該功能微生物對硝酸鹽的平均去除速率約為0.56 mmol/d,對亞硝酸鹽的平均去除速率約為0.83 mmol/d。通過13CH4穩(wěn)定性同位素示蹤技術(shù)定性的驗證了富集培養(yǎng)物厭氧氧化甲烷的過程。同時厭氧間歇實驗結(jié)果表明,甲烷和亞硝酸鹽(硝酸鹽)去除的化學計量數(shù)之比接近理論值3CH4:8NO2-(5CH4:8NO3-)。采用熒光原位雜交(FISH)技術(shù)、構(gòu)建克隆文庫、熒光定量PCR等技術(shù)分析NC10門細菌�？寺∥膸祢炞C了三種富集培養(yǎng)物中反硝化型甲烷厭氧氧化功能細菌——NC10門細菌的存在。熒光原位雜交(FISH)結(jié)果顯示隨著富集時間的延長,NC10門細菌得到了加富,且在13個月后,NC10門細菌的相對豐度達到73%。熒光定量PCR結(jié)果初步表明,經(jīng)過22個月的富集,每克干土樣中NC10細菌的拷貝數(shù)在106左右。2)采用厭氧批式實驗進行反硝化型甲烷厭氧氧化富集條件的分析,主要分析溫度、培養(yǎng)液p H、基質(zhì)濃度、甲烷分壓等對反硝化型甲烷厭氧氧化功能微生物活性的影響。一般認為甲烷的溶解度是影響DAMO過程的最主要因素之一,而甲烷的溶解情況主要受氣相中分壓的影響。當甲烷分壓低于49.72k Pa時,增加甲烷分壓有利于提高DAMO微生物活性;但是當甲烷分壓高于49.72k Pa時,甲烷的溶解度不再是DAMO微生物活性的限制因素。在本實驗條件下,NO2-初始濃度、環(huán)境溫度、培養(yǎng)液p H值分別在1.5mmol/L、25℃、7.48時,該DAMO功能微生物的活性最高。3)首次研究電場對反硝化型甲烷厭氧氧化功能微生物的刺激。外加不同強度的電壓,考察0V、0.5V、1V、1.5V電壓對DAMO功能微生物的刺激;改變加電方式,比較連續(xù)加電和間斷加電作用的差異。研究顯示電場可以強化該實驗條件下DAMO功能微生物的活性。在連續(xù)施加1V電壓時,該功能微生物的活性最強,說明對DAMO功能微生物性能起到促進作用的最佳電壓為1V。但是間斷施加1V的電壓時,該DAMO功能微生物的活性卻被抑制。
[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，

本文編號：2493778