温度及外源CaCO_(3)对砂滤微生物氨氮降解的影响特性  

Effects of temperature and exogenous CaCO_(3) on the microbial degradation of ammonia nitrogen in waterworks sand filters

作　　者：刘明辉 丁陈龙 朱敏[1] 李仪 吴俊康 荆肇乾[1] 余冉[2] LIU Ming-hui;DING Cheng-long;ZHU Min;LI Yi;WU Jun-kang;JING Zhao-qian;YU Ran(School of civil engineering,Nanjing Forestry University,Nanjing 210037,China;School of Energy and Environment,Southeast University,Nanjing 210096,China)

机构地区：[1]南京林业大学土木工程学院,江苏南京210037 [2]东南大学能源与环境学院,江苏南京210096

出　　处：《中国环境科学》2023年第9期4896-4904,共9页China Environmental Science

基　　金：江苏省自然科学基金资助项目(BK20200778);国家自然科学基金资助项目(52270119);江苏省高等学校自然科学研究项目资助项目(20KJB560035)。

摘　　要：本研究考察了在不同温度(10,15,25,37℃),不同氨氮浓度(1和2.5mg-N/L)和外源添加CaCO_(3)条件下水厂砂滤池附着微生物对氨氮污染物的降解性能与群落结构组成变化特性.成功从自来水厂砂滤池中提取出含有硝化菌群的附着物,基于聚合链式反应-电泳技术发现硝化菌群主要包括氨氧化菌,亚硝酸盐氧化菌和完全氨氧化菌.温度影响试验结果表明:温度由25℃降低至10℃时,1和2.5mg-N/L氨氮进水负荷下系统氨氧化速率分别显著降低48.1%和47.3%;低温10℃环境下系统对总氮具有较高的去除能力(~48.1%),但温度降低抑制了系统亚硝酸盐的转化,且氨氮浓度的提高不利于低温条件下氨氮的完全氧化作用;而高温环境(37℃)会使硝化细菌活性丧失.此外,外源添加CaCO_(3)使得系统平均氨氧化速率显著提高90%以上.高通量测序结果显示:低温(10℃和15℃)会显著抑制氨氧化菌属Nitrosospira和Nitrosomonas(相对丰度均<1.0%)的生长,而随着温度的降低,Nitrospira生长竞争超过其他硝化细菌,其相对丰度显著提高63.3%~113.7%;同时,添加CaCO_(3)使得系统Nitrospira相对丰度显著升高约2.5倍,而其他硝化细菌丰度均低于1.0%;故推测低温环境下系统中的完全氨氧化Nitrospira在氨氮降解过程中具有较高的贡献程度.In this paper,the ammonia degradation performance and variations of microbial community composition of the attached microbes in waterworks sand filters under different temperatures(10,15,25 and 37℃),ammonia concentrations(1 and 2.5mg-N/L)and exogenous addition of CaCO_(3)were investigated.The nitrifiers were successfully extracted from the sand filter in the waterworks,which included ammonia oxidizer,nitrite oxidizer and complete ammonia oxidizer as characterized by PCR-electrophoresis.The results of temperature influenced test showed that:the ammonia oxidation rate notably decreased by 48.1%and 47.3%,respectively under 1 and 2.5mg-N/L ammonia concentrations when the temperature decreased from 25℃to 10℃.At 10℃,the system displayed high total nitrogen removal capacity(~48.1%),but the nitrite oxidation activity was significantly inhibited,and the increase of ammonia nitrogen concentrations exerted adverse effects on the nitrite oxidation.In contrast,the temperature as high as 37℃caused the complete loss of the nitrification performance.Moreover,exogenous addition of CaCO_(3)significantly improved the ammonia oxidation rate by more than 90%.High-throughput sequencing results showed that a decrease in temperature(10℃and 15℃)significantly inhibited the growth of Nitrosospira and Nitrosomonas(both relative abundance<1%).When the temperature decreased to 10~15℃,Nitrospira outcompeted the other nitrifiers with the relative abundances increased by 63.3%-113.7%.Besides,the addition of CaCO_(3)caused a 2.5-fold increase in the relative abundance of Nitrospira,while the relative abundances of the other nitrifiers were all less than 1.0%.Therefore,it is inferred that the complete ammonia oxidation Nitrospira under cold condition had a high contribution to ammonia degradation.

关 键 词：硝化细菌 温度 完全氨氧化 高通量测序 

分 类 号：X172[环境科学与工程—环境科学]