铁基材料深度处理后强化印染废水生物脱氮的研究

Research on Iron-based Materials to Enhance Biological Denitrification of Dyeing and Finishing Wastewater after Advanced Treatment

针对印染废水深度处理后TN超标、缺乏易降解有机碳源的问题,本研究探索采用投加铁屑、Cu/Fe双金属(统称“零价铁”)来促进生物反硝化以实现出水TN达标的目的.连续流反应器运行结果表明零价铁强化生物反硝化技术去除硝态氮的能力明显强于传统的生物反硝化技术.结合三维荧光光谱(3-Dimensional fluorescence Excitation Emission Matrix,3D-EEM)、气相色谱质谱联用(Gas Chromatography-Mass Spectrometry,GC-MS)及液相色谱高分辨质谱联用仪(Ultra-Performance Liquid Chromatography with Quadrupole Time of Flight,UPLC-QTOF)等手段,发现铁屑与Cu/Fe双金属组反应器中的有机物相较于对照组在结构上发生了较大变化.宏基因组测序分析发现铁屑和Cu/Fe双金属对微生物群落结构的影响并不相同,Proteobacteria在铁屑和催化铁表面得到了富集(80%左右),明显高于其他样品(<60%),这可能与其表面形成生物膜有关.基于生物信息学数据库(KEGG)分析表明,铁屑和Cu/Fe双金属表面的微生物对应与氮代谢相关基因的序列丰度更高.以上结果揭示了零价铁强化生物反硝化的效果及其微生物学机制.

The study used steel chip and Cu/Fe bimetal(zero-valent iron)to enhance biological denitrification of dyeing and finishing wastewater after advanced treatment to meet the discharge standard,since dyeing and finishing wastewater after advanced treatment still contained high TN and low biodegradable organics.The result showed that zero-valent iron coupled denitrification promoted the biological reduction of nitrate significantly compared to conventional biological denitrification.Based on the analysis of 3D-EEM,GC-MS and UPLC-QTOF,it was found that the structure of organic compounds in steel chip and Cu/Fe bimetal reactors changed greatly.Metagenomic analysis indicated that the impacts of Fe and Cu/Fe bimetal on microbial community structure were different.Proteobacteria was enriched on the Fe surface(80%),apparently higher than the other samples(60%),which might be contributed to the formation of biofilm.The analysis on KEGG showed that the microorganisms on Fe surface had higher abundances of genes relating to nitrogen metabolism.The above results revealed the effect and mechanism of zero-valent iron coupled denitrification.