CEPT 污泥发酵液强化前置反硝化生物滤池脱氮研究

To investigate the effects of different operating parameters on the treatment performance of a pre-denitrification biofilter process, experiments were conducted to determine the optimal hydraulic retention time (HRT), nitrification liquid reflux ratio, and carbon source. The optimal conditions were found to be an HRT of 4 hours, a nitrification liquid reflux ratio of 100%, and the addition of sodium acetate to adjust the COD/TN ratio to 5. Under these optimal conditions, the removal efficiency of various pollutants using chemically enhanced primary treatment (CEPT) sludge fermentation broth as a carbon source decreased compared to sodium acetate but still basically met the effluent requirements. The average specific denitrification rate of the fermentation broth was only slightly lower than that of sodium acetate, further demonstrating the feasibility of using the fermentation broth as a carbon source for denitrification. Analysis of the microbial community composition showed that the abundances of Chloroflexi and Actinobacteria in the Y-A group were higher than those in the F-A group, which may explain why the denitrification effect of sodium acetate was better than that of sludge fermentation broth. Functional analysis showed that the abundance of napAB, narGHI, and nirKS genes in the Y-A group was slightly higher than that in the F-A group, which may be one of the reasons why adding sodium acetate resulted in stronger denitrification performance compared to CEPT sludge fermentation broth.