气水比对后置固相反硝化滤池工艺脱氮及微生物群落影响

Effects of Gas/Water Ratio on the Characteristics of Nitrogen Removal and the Microbial Community in Post Solid-Phase Denitrification Biofilter Process

为解决现有低碳源污水处理工艺能耗高、工艺复杂和脱氮效果不佳等问题,首次提出一种新型的混凝沉淀/后置固相反硝化滤池工艺(CS-BAF-SPDB).重点研究了气水比对该工艺脱氮效率的影响,同时采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术从微观微生物群落的角度揭示了宏观运行条件对脱氮效率影响的机理.研究结果表明,为同时获得理想的硝化和反硝化效果,后置固相反硝化滤池工艺中硝化滤池的气水比应该设定为4∶1.同时,宏观运行参数对BAF和SPDB处理效果的影响和微观微生物群落的动态变化直接相关.在BAF中氨氧化菌(Candidatus Nitrospira defluvii)和亚硝酸盐氧化菌(Nitrosomonas sp.Nm47)的组成、数量与活性随气水比的变化直接决定了BAF中硝化效果的好坏,而SPDB中固体碳源降解反硝化微生物Pseudomonas sp.、Myxobacterium AT3-03和异养反硝化菌Dechloromonas agitate、Comamonas granuli和Rubrivivax gelatinosus的群落结构随气水比的变化直接决定了SPDB中有机碳源的释放和反硝化效能的优劣.

To solve the problems of high-energy consumption,complex processes,and low nitrogen removal efficiency in the currently available low carbon source wastewater treatment processes,a novel coagulation sedimentation/post solid-phase denitrification biofilter process（ CS-BAF-SPDB） was proposed. The effect of gas/water ratio on nitrogen removal efficiency of the CS-BAF-SPDB was studied.The changes in the microbial community structure along the varying gas/water ratio were investigated,and the functional bacteria were identified using polymerase chain reaction-denaturing gradient gel electrophoresis（ PCR-DGGE）. The results showed that,to realize favorable nitrifying and denitrifying performance simultaneously in the BAF-SPDB unit,the gas/water ratio of the BAF should be set at4∶ 1. In addition,the influence of the macro operational parameters on the performance of the BAF and SPDB had a direct relationship with the dynamic changes in the micro microbial community. The influence of gas/water ratio on nitrification performance in the BAF was mainly embodied in the changes of composition,amount,and activity of ammonia-oxidizing bacteria Candidatus and Nitrospira defluvii and nitrite-oxidizing bacteria Nitrosomonas sp. Nm47,whereas that on denitrification performance in the SPDB was mainly embodied in the changes of composition and amount of solid carbon substrate degrading denitrifying bacteria Pseudomonas sp. and Myxobacterium AT3-03 and heterotrophic denitrifying bacteria Dechloromonas agitate,Comamonas granuli,and Rubrivivax gelatinosus.