新型组合工艺处理印染废水中试效能及微生物菌群分析

Pilot test performance and microflora analysis of a new combined process treating printing and dyeing wastewater

以江苏省印染行业废水处理厂提标为基础,构建了生物吸附-MBBR-硫自养反硝化-活性焦滤池为主体工艺的印染废水处理中试系统,优化系统运行参数,考察该系统对污染物去除效果及微生物菌群特征,并核算其运行成本。中试运行结果表明,在生物吸附池(HRT为1.2 h,DO为1 mg·L-1)和MBBR池(HRT为12 h,DO为7 mg·L-1)的条件下,系统达到最优处理效能,出水COD、 TN、 TP和NH3-N分别稳定低于30、 5、 0.3和0.5 mg·L-1;使用3D-EEM、FT-IR和GC-MS等方法,分析了该印染废水在处理过程中污染物的去除及迁移转化规律。可以看出,出水中主要存在酪氨酸/色氨酸类物质,大部分蛋白质与腐殖酸类物质被去除;各单元出水中存在不饱和双键类和芳香类化合物,典型官能团以C—OH、C=O和C—O—C为主;出水中主要成分为2,4-二叔丁基酚和N-甲基三氟乙酰胺。同时对中试系统各生物单元进行微生物菌群结构分析,发现生物吸附段微生物种类较为丰富,MBBR生物膜中Nitrospira菌属的相对丰度上升明显,硫自养池中Proteobacteria菌门为绝对优势菌门。经核算,中试系统的处理成本约为1.83元·m-3,显著低于实际污水处理厂的处理成本(2.50元·m-3)。该方法可为印染废水处理效能与菌群多样性关系的研究及其工程化应用提供参考。

Based on the standard upgrading of Jiangsu printing and dyeing industry wastewater treatment plant,a pilot test system for printing and dyeing wastewater treatment with the main process of biosorption-MBBRsulfur autotrophic denitrification activated coke filter was constructed. Its operation parameters were optimized,its removal effect of pollutants and the characteristics of microflora were investigated, and its operation cost was calculated. The results of pilot test showed that under the conditions for biosorption tank: HRT of 1.2 h, DO of1 mg·L-1 and for MBBR tank: HRT of 12 h, DO of 7 mg·L-1, the system achieves the best performance, and the effluent COD, TN, TP and NH3-N were stabilized below 30, 5, 0.3 and 0.5 mg·L-1, respectively. By means of3 D-EEM, FT-IR and GC-MS, the removal, migration and transformation of pollutants during the printing and dyeing wastewater treatment were analyzed. It was found that tyrosine/tryptophan existed in the effluent, most of the protein and humic acid-like substance were removed;in the effluent of each unit, there were unsaturated double bond and aromatic compounds with the typical functional groups of C—OH, C=O and C—O—C. The main components in the effluent were 2,4-di-tert-butylphenol and N-methyl-trifluoroacetamide. At the same time, the microbial community structure of each biological unit in the pilot system was analyzed. It was found that the microbial species in the biosorption section were relatively rich, the relative abundance of Nitrospira in MBBR biofilm increased significantly, and Proteobacteria in sulfur autotrophic pool was the absolute dominant phylum. After calculation, the treatment cost of the pilot system was about 1.83 yuan·m-3, which was significantly lower than 2.50 yuan·m-3 for the actual sewage treatment plant. This method provides theoretical guidance for the relationship between the treatment efficiency of printing and dyeing wastewater and the diversity of microflora, and provides reference for its engineering application.