研究论文
邹雨璇,祝贵兵,冯晓娟,夏超,周磊榴.低温条件下湿地氨氮强化净化技术及其氨氧化微生物机制[J].环境科学学报,2014,34(4):864-871
低温条件下湿地氨氮强化净化技术及其氨氧化微生物机制
- Enhanced ammonium-N removal in a constructed wetland and the microbial mechanisms of ammonia-oxidization at low temperature
- 基金项目：国家自然科学基金 （No.21077119）；“十二五”科技支撑计划课题（No.2012BAJ21B04-01）；中国科学院知识创新工程重要方向项目课题（No.KZZD-EW-09-3）；环境模拟与污染控制国家重点联合实验室专项经费项目（No.12L03ESPC）；北京市科技新星计划项目（No.2011095）
- 作者
- 单位
- 邹雨璇
- 1. 吉林大学 地下水资源与环境教育部重点实验室, 长春 130021;2. 中国科学院生态环境研究中心 环境水质学国家重点实验室, 北京 100085
- 祝贵兵
- 中国科学院生态环境研究中心 环境水质学国家重点实验室, 北京 100085
- 冯晓娟
- 1. 中国科学院生态环境研究中心 环境水质学国家重点实验室, 北京 100085;2. 中国中建设计集团有限公司, 北京 100085
- 夏超
- 中国科学院生态环境研究中心 环境水质学国家重点实验室, 北京 100085
- 周磊榴
- 中国科学院生态环境研究中心 环境水质学国家重点实验室, 北京 100085
- 摘要：针对北方寒冷冬季水源地氨氮微污染水体的特征，构建间歇流人工湿地系统并同步采用分子生物学方法对湿地系统中的氨氧化古菌和氨氧化细菌的丰度和古菌的多样性进行分析，并结合硝化速率潜势来研究氨氧化古菌和氨氧化细菌在氨氧化过程中的作用.结果表明：平均气温为5 ℃时，最佳运行工况为：停留时间21 h，水力负荷4.2 cm·d-1，氨氮去除率达99%；平均气温为-5 ℃时，最佳运行工况为：水力停留时间为21 h，水力负荷3.6 cm·d-1，氨氮去除率达81%，去除效率稳定.在低温条件下，氨氧化古菌和氨氧化细菌中amoA基因的丰度会因温度降低而减少，古菌中amoA基因丰度高于细菌 2.9~33.2倍，且硝化速率潜势与氨氧化古菌中amoA基因丰度呈正向变化趋势，而与氨氧化细菌无显著相关，表明氨氧化古菌在低温条件下的氨氧化过程中起主导作用.湿地系统中的氨氧化古菌的生物多样性具有季节性变化，系统发育分析显示，夏季样品8个OTU全部属于土壤支系；冬季样品11个OTU序列属于土壤支系，2个OTU序列属于海洋水体支系，多样性较高.夏季和冬季样品中氨氧化古菌均属于一个新命名的古菌类群——奇古菌门（Thaumarchaeota）.本文建立了一种在低温条件下基于氨氧化古菌有效强化湿地氨氮净化处理的稳定运行技术，为寒冷地区强化湿地去除氨氮提供了理论依据.
- Abstract：Based on the characteristics of micro-pollution source water by ammonium-N at low temperature in North China, a batch flow wetland system was constructed in this study. With the method of molecular biology (qualitative/quantitative PCR and clone libraries), abundances of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), and the biodiversity of AOA from the soil in the constructed wetland were analyzed at the molecular level, and the contribution of AOA to ammonia oxidization was also analyzed in combination with the potential nitrification rate (PNR). These results suggested that, for this unit a 21 h hydraulic retention time, 4.2 cm·d-1 hydraulic loading was sufficient at mean temperature of 5 ℃, and the ammonium-N removal efficiency was 99%; but at mean temperature of -5 ℃, reducing hydraulic loading to 3.6 cm·d-1 could keep ammonium-N removal efficiency to 81% and stable. The number of archaeal amoA genes (1.1×108~8.87×109 copies·g-1) was 2.9~33.2 times higher than that of bacterial amoA genes (8.16×108~5.7×107 copies·g-1). However, they both decreased as the temperature dropped. The PNR correlated positively with the number of archaeal amoA genes. It had however no significant correlation with bacteria amoA gene, which indicated the dominant role of AOA in ammonia oxidization process at low temperature. In the analysis of biodiversity, AOA had high community diversity and changed seasonally under low temperature. 8 operational taxonomic units (Operational Taxonomic Unit, OTU) from summer samples and 11 OTUs from winter samples belonged to soil lineage, while 2 OTUs from winter samples belonged to marine lineage. All archaeal amoA sequences in the constructed wetland were attributed to a newly named archaea cluster "Thaumarchaeota". Based on ammonia-oxidizing microorganisms, this study developed an ammonium elimination method that could be operated stably under low temperature in constructed wetlands, and the results provided theoretical basis for the ammonium elimination in wetland systems in cold area.
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