DNBF-O3-GAC组合工艺深度脱除氮磷及代谢产物

为提高污水厂尾水水质,本研究采用新型缓释碳源复配海绵铁、活性炭作为反硝化生物滤池的复合填料,分别以模拟二级处理出水和实际污水厂尾水为进水,考察了复合缓释碳源填料反硝化生物滤池-臭氧-活性炭(DNBF-O_3-GAC)组合工艺同步脱氮除磷及去除微生物代谢产物的性能,并借助Mi Seq高通量测序技术分析了反硝化生物滤池生物膜中的微生物群落结构特征.结果表明,组合工艺取得了较好的脱氮除磷及微生物代谢产物的效果:模拟配水阶段和实际尾水阶段NO_3~--N平均去除率分别达到88.87%、79.99%;TP平均去除率分别达到87.67%、65.51%;UV254平均去除率分别达到45.51%、49.23%.组合工艺各处理单元具有不同的功能:NO_3~--N、TN、TP、TFe的变化主要发生在反硝化生物滤池反应器中;UV254、三维荧光强度的变化主要发生在臭氧-活性炭反应器中.微生物在属水平进行聚类分析结果表明,反硝化脱氮系统存在硫自养反硝化菌和异养反硝化菌,当实际尾水阶段碳源相对不足时,硫自养反硝化作用有了显著加强,Thiobacillus(硫杆菌属)的占比由7.44%上升至29.62%,硫自养反硝化与异养反硝化形成的这种互补作用延长了新型缓释碳源的使用周期.

Combined Process of DNBF-O3-GAC for Nitrogen and Phosphorus and Metabolite Advanced Removal

To improve the quality of the tailings water from a wastewater treatment plant (WWTP), a denitrification biofilter (DNBF) with a composite filler composed of a new slow-release organic-carbon source (SOC-F), sponge iron, and activated carbon was tested. Studies were conducted in the combined process of DNBF-O₃-GAC to explore the efficiency of the advanced removal of nitrogen, phosphorus, and microbial metabolite by using synthetic effluent made from running water and chemicals. Corresponding comparative studies were conducted by using the secondary effluent from the WWTP. The microbial population structure in the biofilm of the denitrification biofilter was analyzed by adopting MiSeq high-throughput sequencing technologies. The results indicated that the combination process achieved high efficiency removal of nitrogen, phosphorus, and microbial metabolite. The average removal rate of NO₃^--N in the simulated and actual water period reached 88.87% and 79.99%, respectively; the average removal rate of TP reached 87.67% and 65.51%, respectively; and the average removal rate of UV₂₅₄ reached 45.51% and 49.23%, respectively. Each processing unit had different functions. The changes in NO₃^--N, TN, TP, and TFe mainly occurred in the denitrification biofilter, and the removal of UV₂₅₄ and the change in the three-dimensional fluorescence intensity mainly occurred in the ozone-activated carbon reactor. The cluster analysis at the genus level indicated that the denitrification system had sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria. Sulfur autotrophic denitrification increased obviously in the actual water period when relatively lack of carbon sources, and the proportion of Thiobacillus increased from 7.44% to 29.62%. The complementary effect of sulfur autotrophic denitrification and heterotrophic denitrification had extended the use of the new slow-release carbon source.