反硝化生物滤池深度脱氮中试运行效能及微生物菌群分析

Deep Denitrification Performance in Pilot-scale Denitrification Biofilter System and Microbial Community

摘要:

以污水处理厂二级出水为原水，开展了水力负荷、碳氮比和温度等关键参数的中试运行效能研究。中试系统中主要利用外加碳源而不是二级出水原水中的有机物进行反硝化，较优的水力负荷和碳氮比分别为5 m·h^-1和4，对化学需氧量（COD）和总氮（TN）的去除率分别为62.8%和67.3%；在温度为15~27 ℃时，中试系统的出水TN稳定在10.0 mg·L^-1以下。中试系统中，不仅Hyphomicrobium和Methyloversatilis等传统反硝化细菌的相对丰度较高（占25.12%），Methylotenera和Paracoccus等同步硝化反硝化细菌的相对丰度也较高（占33.29%），以上优势菌种的存在保证了系统的高效脱氮效果。

Abstract:

A pilot-scale denitrification biofilter system was constructed to investigate the deep denitrification performance when the actual secondary effluent was adopted， and the effects of key parameters （i.e. hydraulic load， C/N ratio and temperature） on the operation were carried out. The pilot-scale system mainly used external carbon source for denitrification rather than organic matter existed in the secondary effluent. The recommended hydraulic loading and C/N ratio was 5 m·h^-1 and 4， and under the conditions the average removal efficiencies of COD and TN were 62.8% and 67.3%， respectively. When the temperature was 15~27 ^oC， TN in the effluent was steady below 10.0 mg·L^-1. The relative abundances of conventional denitrifiers such as Hyphomicrobium and Methyloversatilis （accounted for 25.12%） were higher in the pilot-scale denitrification biofilter system， and the relative abundances of simultaneous nitrification-denitrification bacteria such as Methylotenera and Paracoccus were also much higher （accounted for 33.29%）. These bacteria guaranteed the good denitrification performance in the system.