SBR工艺污水生物脱氮过程中N2O的释放特征  

N2O EMISSION CHARACTERISTICS DURING BIOLOGICAL NITROGEN REMOVAL FROM WASTEWATER IN A SBR SYSTEM

作　　者：刘国华[1] 庞毓旻 齐鲁[1] 王洪臣[1] LIU Guo-hua;PANG Yu-min;QI Lu;WANG Hong-chen(Low-Carbon Water Environment Technology Centre,School of Environment&Natural Resource,Renmin University of China,Beijing 100872,China)

机构地区：[1]中国人民大学环境学院低碳水环境技术中心,北京100872

出　　处：《环境工程》2020年第7期51-57,共7页Environmental Engineering

基　　金：中国人民大学教师教学发展改革项目(A类)。

摘　　要：N2O是一种可以导致严重全球变暖的主要温室气体,污水的生物除氮处理过程被认为是N2O释放的重要来源。探究了缺氧-好氧(A/O)模式下SBR系统中N2O的释放特征和主要来源。结果表明:N2O的释放主要发生在SBR系统的好氧阶段,其最大释放速率达到2.02μg/(min·g),累积释放量为8.2 mg,好氧运行120 min时,测得NO2^--N的累积浓度达到了最高值7.5 mg/L,NO2^--N的积累和N2O的释放呈正相关性。细菌群落分析发现,A/O-SBR系统好氧阶段的一些优势菌被鉴定为黄杆菌(Flavobacteria),它们中的部分种群具有好氧反硝化的作用,然而NO2^--N累积会抑制该类细菌的亚硝酸还原酶(Nos)活性,进而使N2O进一步还原为N2的途径受阻而释放N2O。因此,在污水生物处理过程中,应减少或避免NO2^--N的积累。N2O is a typical greenhouse gas,and contributes severely to global warming. The process for biological nitrogen removal from wastewater is considered as an important source of N2O emission. The present study investigated the characteristics and main source of N2O in a SBR system,with an anoxic-aerobic (A/O) running mode. The results showed that N2O emission occurred mainly during the aerobic phase in the A/O SBR system. The maximum N2O emission rate reached 2. 02 μg/ (min·g),and the cumulative N2O emission during the aerobic phase was 8. 2 mg,then the nitrite accumulation concentrate was observed to get the highest value of 7. 5 mg/L after 120-minite operation. On the basis of bacterial community analysis,the bacteria in the dominant DGGE bands were identified as Flavobacteria,some of which was found to be aerobic denitrifying bacteria. It was inferred that the accumulation of nitrite might inhibit the activity of nitrous oxide reductase (Nos)from aerobic denitrifying bacteria and lead to N2O emission. The accumulation of nitrite should be avoided or reduced in real biological wastewater treatment process.

关 键 词：N2O释放 NO2^--N 好氧反硝化细菌 SBR 生物脱氮 

分 类 号：X703[环境科学与工程—环境工程]