IEM-UF同步分离反硝化系统脱氮特性及种群结构分析

针对传统脱氮工艺处理低C/N污水存在的问题,本研究提出IEM-UF同步分离反硝化系统.考察了三阶段各反应器对系统COD去除与脱氮性能影响,同时应用宏全基因组技术分析了各反应器功能微生物种群结构特征.结果表明,系统在电流强度0. 2A时分离器氨氮富集率平均达到116. 1%,最高可达170%;系统进水C/N为2. 80稳定运行时,系统COD及TN平均去除率分别可以达到90%和50%以上. TN去除率最高达到65. 4%.宏全基因组测序表明,在硝化反应器中硝化螺旋菌属(Nitrospira)和亚硝化单胞菌属(Nitrosomonas)所占比例分别为12. 23%和2. 31%;在反硝化反应器中脱氯单胞菌属(Dechloromonas)、陶厄氏菌属(Thauera)和Azospira所占比例分别为4. 57%、1. 76%和1. 03%,远大于其他菌属所占比例,保证了系统中COD、NH_4~+-N、NO_x~--N较高的去除率;同时铁自养反硝化菌的存在提高了系统的反硝化效率.

Nitrogen Removal Characteristics and Analysis of Microbial Community Structure in an IEM-UF Simultaneous Separation and Denitrification System

A system that combines an ion exchange membrane and ultrafiltration membrane (IEM-UF) to form a simultaneous separation and denitrification system was proposed for domestic sewage with a low carbon/nitrogen ratio. The removal of nitrogen and COD in the system was studied under a three phase operating condition. The characteristics of the microbial community in each reactor were analyzed using metagenomics. The results show that, the average rate of ammonia nitrogen enrichment in the separator reached above 116.1% when the current intensity was 0.2 A. When the system was at C/N 2.80 and operating well, the average removal rates of COD and TN reached above 90% and 50%, respectively. The maximum removal rate of TN was above 65.4%. The results of metagenomics showed a genus of phylum Nitrospirae (Nitrospira) and a genus of phylum Proteobacteria (Nitrosomonas), with the proportions of 12.23% and 2.31%, respectively. In the denitrifying reactor, Dechloromonas, Thauera, and Azospira were detected in the proportions 4.57%, 1.76%, and 1.03%, respectively. These proportions were far larger than those of other bacteria in this reactor. Meanwhile, the presence of iron autotrophic denitrifying bacteria increased the denitrification efficiency of the system.