有机碳源对SNAD工艺脱氮性能及微生物种群结构的影响

Effect of organic carbon on nitrogen removal and the microbial communities in SNAD process

摘要:

为考察不同有机碳源质量浓度对亚硝化的全程自养脱氮工艺（SNAD）脱氮性能的影响，将该工艺应用到生活污水的处理中，采用MBR反应器，以葡萄糖作为有机物来源，通过逐步增大COD来实现，并运用PCR-DGGE技术研究了微生物种群结构的变化.反应器运行结果和DGGE图谱分析表明：碳氮比为0~2时，COD的增加不会抑制AOB和Anammox菌，AOB和Anammox菌的菌属种类不受影响，反而通过反硝化作用提高氮去除负荷.总氮去除率和氮去除负荷分别为67%和0.34 kg/（m³·d）左右.碳氮比为3~4及生活污水运行条件下，Anammox菌不受影响，AOB的活性受到抑制，菌属种类减少，脱氮效率下降.生活污水运行阶段，总氮去除率和氮去除负荷平均分别为73%和0.17 kg/（m³·d）.Nitrosomonas和Candidatus Kuenenia stuttgartiensis一直是反应器内的优势菌属，共同完成脱氮过程.

Abstract:

Effect of different organic substrate concentration on nitrogen removal in SNAD and the application of this process to treat domestic wastewater were investigated in a MBR, with gradually increased glucose as a source of organic matter. Besides, changes of microbial communities were observed by PCR-DGGE techniques. Experimental results and DGGE profiles showed that the increase of organic carbon concentration did not inhibited the activity and category species of AOB and Anammox bacteria when the C/N ration was ranged 0 to 2.0. Meanwhile, a significantly improvement of nitrogen removal was observed via effective denitrification, with a total nitrogen removal efficiency of 67% and nitrogen removal rate of 0.34 kg/(m³·d), respectively. Under the C/N of 3-4 condition, the anammox bacteria in the system changed insignificantly, but AOB was inhibited and the category species reduced, resulting a decreasing of nitrogen removal efficiency.Total nitrogen removal efficiency and nitrogen removal rate were about 73% and 0.17 kg/(m³·d), respectively.Nitrosomonas and Candidatus Kuenenia stuttgartiensis were the predominant microorganisms in the SNAD reactor and played a major role in autotrophic nitrogen removal.