甲烷为唯一电子供体驱动硝酸盐/亚硝酸生物还原及微生物群落结构分析

The denitrifying anaerobic methane oxidation (DAMO) organisms are difficult to enrich successfully in a short time due to their slowly growth. In order to rapidly and massively enrich the functional bacteria of nitrate/nitrite type anaerobic methane oxidation, choosing suitable hollow fiber material according to methane flux to build new membrane biofilm reavtors. During the initial 76 days, two MBfRs both could reduce 200 mg•L^-1 NO₃^--N or NO₂^--N within 10 days. Using nitrate as electron acceptor could be stabilized to remove all 200 mg•L^-1 within 2 days, which was slightly faster than nitrite. Both groups of microorganisms could achieve the reduction efficiency of 50 mg•L^-1•d^-1 in SBR running period during day 77 to 124. and the success of microbial enrichment and membrane hanging could be observed. The whole enrichment process was accompanied by the detection of volatile fatty acids (VFAs) in the effluent. The maximum VFAs concentration in the reactor with nitrate or nitrite as electron acceptor could reach to 948 mg•L^-1and 997 mg•L^-1, respectively. The high-throughput sequencing results showed that the abundance of Propionispora and Proteiniphilum could reach 39.1% and 3.1% in the MBfR with nitrate as electron accepter, while the abundance of the same genera could reach 80.9% and 2.4% when the electron accepter changed to nitrite, which were always the dominant genera in the MBfRs. The denitrifying bacteria Pseudomonas was a dominant genus detected in both two microbial enrichment stages. It could be speculated that VFAs were most likely intermediates during the nitrate/nitrite type anaerobic methane oxidation process. This research results can provide reference to promote the development of wastewater denitrification technology.