葡萄糖碳源下焦化纳滤浓水脱氮性能及微生物机理分析

Nitrogen Removal Performance and Microbial Mechanism Analysis of Nanofiltration Concentrate from Coking Wastewater with Glucose As the Carbon Source

以焦化废水膜处理系统的纳滤浓水为研究对象,采用葡萄糖为碳源,开展了91 d的序批式生物反应器(SBR)工艺生物脱氮试验,考察了焦化纳滤浓水的脱氮性能,并结合高通量测序和qPCR定量分析方法探究了纳滤浓水脱氮的微生物机理。结果显示SBR稳定运行期间(31~91 d),总氮和硝态氮的去除率分别为51.8%~67.8%和91.9%~96.9%,表明葡萄糖碳源条件下SBR生物反硝化工艺处理高电导率焦化纳滤浓水过程表现出良好的脱氮性能。微生物分析显示Proteobacteria(变形菌门)和Bacteroidetes(拟杆菌门)是纳滤浓水生物脱氮过程最主要的优势菌门,且多种反硝化功能菌属与功能基因的丰度在SBR运行过程中保持动态平衡,表明反硝化功能细菌与功能基因参与驱动了纳滤浓水生物脱氮过程。此外,nirS的绝对丰度较nirK高101~102,在亚硝氮转化过程起重要作用。

A biological denitrifying process using glucose as the carbon source by sequencing batch bioreactor(SBR) was employed to treat nanofiltration(NF) concentrate produced from the coking wastewater membrane treatment system.The nitrogen removal performance of NF concentrate from coking wastewater was investigated.Moreover,high-throughput sequencing and qPCR analysis were employed to learn the microbial mechanisms of denitrification.The results showed that the removal rates of total nitrogen and nitrate nitrogen were 51.8%~67.8% and 91.9%~96.9%,respectively during the stable operation of SBR(31~91 d).It indicated that the SBR biological denitrification process with glucose as the carbon source possessed good nitrogen removal performance treating NF concentrate with high conductivity.Microbial analysis showed that Proteobacteria and Bacteroidetes were the most dominant phyla in the biological denitrification process of NF concentrate.Besides,the dynamic balance of the abundances of several denitrifying functional bacteria and functional genes was achieved in SBR during the process.The results suggested that the denitrifying bacteria and functional genes were involved in driving the biological denitrification process of NF concentrate.In addition,the absolute abundance of nirS was 101~102 higher than nirK,making nirS as the essential functional gene responsible for nitrite conversion.