不同环境因素对厌氧甲烷氧化型自养反硝化系统脱氮性能的影响及其微生物群落分析

采用序批实验研究了不同环境因素(甲烷供应、初始硝氮浓度和pH值)对厌氧甲烷氧化型反硝化系统脱氮性能的影响,并采用高通量测序对不同pH下反应器内微生物群落结构进行了分析.结果 表明:当甲烷供给充足时,系统反硝化效果明显;随着初始硝氮浓度的升高,系统平均脱氮率呈现先升高后下降的趋势,表明适当增大硝氮质量浓度(＜30 mg·...

Effects of different environmental factors on the denitrification performance and microbial community of an autotrophic denitrification system based on anaerobic methane oxidation

Effects of different environmental factors (methane supply, initial nitrate concentration and pH value) on the denitrification performance of the anaerobic methane oxidized denitrification system were investigated through batch experiments, and the microbial community structure in the reactor at different pH values was analyzed by high-throughput sequencing. Results indicated that effective denitrification could be achieved with the sufficient supply of methane. With the increase of the initial nitrate concentration, the average denitrification rate of the system primarily increased and then decreased, indicating that denitrification rate could be improved by appropriately increasing the initial nitrate concentration (< 30 mg·L−1). The system exhibited good denitrification capability under different ambient pH (pH=6~9), with the highest denitrification rate achieved at neutral and slightly alkaline conditions. High-throughput sequencing found that the microbial abundance was the highest at pH=7 and pH=8, and the diversity and uniformity were moderate. With the increase of pH, the diversity and uniformity of microorganisms increased, indicating that the alkaline environment can improve microorganisms diversity and uniformity. Gammaproteobacteria, Deltaproteobacteria, Bacterodia, Ignavibacteria and Anaerolineae were the dominant classes at different pH values. When pH=8, methanotroph Methylocystis was abundantly enriched, and when pH=6, methanotroph Methylotenera and Methylophilaceae were enriched. Environmental pH had a selective effect on the microbial community structure, and the dominant microorganisms in different pH environments were different.