碳氮比对不同滤料反硝化滤池脱氮效果的影响

以乙酸钠为碳源，分别考察了以石英砂和生物陶粒为滤料的2种反硝化滤池在不同C/N比条件下的脱氮效果，并对生物膜量和微生物种群进行了分析。结果表明：2种滤池对硝酸盐和TN都有较好的去除效果，且生物陶粒滤池要明显优于石英砂滤池；从经济性考虑，C/N比为4时的碳源投加量是最佳的，此时石英砂池和生物陶粒池出水TN平均浓度分别低于10 mg·L-1和5 mg·L-1，亚硝酸盐含量在0.5 mg·L-1以下。2柱的生物膜量沿着水流方向都逐渐减少，且生物陶粒池的生物膜量明显高于石英砂池。高通量测序结果表明，2滤池系统的物种多样性相差不大，在门的分类水平上，2个系统的主要优势菌群都属于Proteobacteria（变形菌门），含量在94%以上；在属的分类水平上，2柱的反硝化功能菌都主要是Dechloromonas（脱氯单胞菌属）和Thauera（陶厄氏菌属），但含量上存在一定差异。

Effect of C/N ratio on denitrification of denitrification filters with different filter materials

In this study, denitrification filters were used to further decrease the amount of nitrate, and sodium acetate was added as a carbon (C) source. Denitrification effects of the two filters with different filter materials (silica sand or bioceramic) were evaluated at different C/N ratios, and the biomass and microbial community in the filters were also analyzed. Both filters showed good efficiency of removal of nitrate and TN; the filter filled with bioceramic showed greater denitrification efficiency than did the filter filled with quartz sand. In terms of cost, the optimal C/N ratio was 4 for both filters. At this C/N ratio, the average concentration of TN in the effluent from the silica filter and bioceramic filter was lower than 10 and 5 mg·L-1, respectively, and the nitrite concentration was lower than 0.5 mg·L-1. Biomass in the two filters decreased gradually along the flow direction, and biomass in the bioceramic filter was much higher than that in the silica sand filter. High throughput sequencing analysis revealed that the diversity of species was not different between the two filters. On the phylum level, the main bacterial group belonged to Proteobacteria,and they accounted for 94% of all sequencing reads. On the genus level, the main bacteria responsible for denitrification were Dechloromonas and Thauera, but their proportions were different between the two filters.