摘要 群体感应信号分子对污水处理过程中微生物行为和功能微生物含量具有重要影响,但目前其对生物脱氮过程中氧化亚氮(N2O)产生的影响尚不明确.为探明群体感应与N2O产生的关联机制,选取两种N-酰化高丝氨酸内酯类化合物(AHLs)信号分子C6-HSL(N-己酰L-高丝氨酸内酯)和C8-HSL(N-辛酰-L-高丝氨酸内酯),在AO工艺中研究其外源性投加对污水处理效果、N2O产生特征及微生物群落结构的影响.结果表明:①信号分子C6-HSL和C8-HSL能够显著提高处理系统的生物脱氮效率,2个反应器的硝化速率显著升高,NH4+-N去除率分别提高了1.7%和2.2%,TN去除率分别提高了7.6%和5.4%,但CODCr去除率没有发生明显变化.②信号分子对N2O产生量影响显著,投加C6-HSL和C8-HSL的反应器N2O产生总量分别增加了39.0%和11.0%,N2O增量的主要产生途径为好氧处理阶段的硝化细菌反硝化反应.③微生物分析结果显示,污泥中的微生物群落结构,以及与生物脱氮相关的功能微生物含量发生显著变化,投加C6-HSL和C8-HSL的反应器氨氧化细菌(AOB)相对丰度由0.3%分别提至0.5%和0.4%,硝化细菌(NOB)相对丰度由0.03%分别增至0.07%和0.08%,反硝化细菌(DNB)的相对丰度由6.3%分别升至8.5%和7.5%.研究显示,AHLs类外源性信号分子能够显著提高污水生物脱氮过程中关键功能微生物AOB、NOB和DNB的相对丰度,进而提升污水处理效果,但同时增加系统N2O释放量. Quorum sensing signal molecules have a significant influence on the microbial behavior and the contents of functional microorganisms in the wastewater treatment process,but its impact on the nitrous oxide(N2O)generation in the biological nitrogen removal process is still unclear.To explore the mechanism between quorum sensing and N2O generation,two kinds of N-acylated homoserine lactones(AHLs)signal molecules N-hexanoyl-L-homoserine lactone(C6-HSL)and N-octanoyl-L-homoserine lactone(C8-HSL)were used to study the effects of exogenous addition of AHLs on treatment performance,N2O production characteristics and microbial community structure in an AO process.The results showed that:(1)The signal molecules of C6-HSL and C8-HSL could significantly enhance the biological nitrogen removal.The nitrification rates of the two bioreactors increased observably.The NH4+-N removal rate increased by 1.7%and 2.2%,and the TN removal rate increased by 7.6%and 5.4%,respectively.However,the CODCr removal rates did not change obviously.(2)With the addition of C6-HSL and C8-HSL,the total N2O production in the systems increased by 39.0%and 11.0%,respectively.Nitrifier denitrification was the main N2O producing approach in the aerobic treatment stage.(3)Microbiological analysis showed that the microbial community structure and the functional microorganisms involved in biological nitrogen removal in activated sludge varied obviously.With the addition of C6-HSL and C8-HSL,the relative abundance of AOB(ammonia oxidizing bacteria)increased from 0.3%to 0.5%and 0.4%;the relative abundance of NOB(nitrifying bacteria)increased from 0.03%to 0.07%and 0.08%;the relative abundance of DNB(denitrifying bacteria)increased from 6.3%to 8.5%and 7.5%,respectively.The study indicated that AHLs exogenous signaling molecules could increase the relative abundance of functional bacteria AOB,NOB and DNB in biological nitrogen removal processes,resulting in an enhancement of the treatment performance and N2O generat
机构地区 河南师范大学环境学院 河南省生态环境监测中心
出处 《环境科学研究》 CAS CSCD 北大核心 2021年第4期920-926,共7页 Research of Environmental Sciences
基金 国家自然科学基金项目(No.51408199) 河南省科技攻关计划项目(No.202102310600) 河南师范大学青年基金项目(No.2019QK09)。
关键词 污水处理 氧化亚氮(N2O) 信号分子 微生物群落结构 sewage treatment nitrous oxide(N2O) signal molecule microbial community structure
