典型炼化废水微生物功能结构与主要致毒物质响应关系研究

为探明典型炼化废水处理系统(简称“系统”)生物毒性削减效果、主要致毒物质类别及微生物功能响应关系，以费氏弧菌和鼠伤寒沙门氏菌为受试生物，测试系统沿程生物急性毒性及遗传毒性，并结合毒性鉴别评价方法甄别系统主要致毒物质，同时利用高通量测序技术探究系统微生物功能结构与主要致毒物质响应关系.结果表明：(1)系统沿程生物毒性总体呈下降趋势，生化处理单元进水为急性毒性微毒、遗传毒性阳性.其中，炼油废水急性毒性总削减率为86.514%，遗传毒性总削减率为96.221%；化工废水急性毒性总削减率为53.281%，遗传毒性总削减率为62.273%.(2)通过毒性鉴别评价方法 (toxicity identification evaluation,TIE)结果推断，炼油废水主要致毒物质可能为阳离子金属及非极性有机物，化工废水主要致毒物质可能为阳离子金属.(3)CCA分析表明，NH3-N浓度(r=0.819,p=0.001)、Cr浓度(r=0.777,p=0.002)、TPH (total petroleum hydrocarbon，总石油烃)浓度(r=0.752,p=0.002)与生化处理前微生物群落结构...

Relationship between Microbial Diversity and Main Toxic Substances in Typical Refinery Wastewater

In order to investigate the relationship between the biotoxicity reduction effect of a typical refinery wastewater treatment system (hereafter referred to as system), the main types of toxic substances and the response of functional microorganisms, Vibrio fischeri and Salmonella typhimurium were used as test organisms to examine the acute toxicity and genotoxicity with the process of the system. We used the toxicity identification evaluation (TIE) to identify the main toxic substances in the system, and used the high-throughput sequencing to explore the relationship between the microbial functional structure and the main toxic substances. The results showed that: (1) The biological toxicity showed a decreasing trend with the process in the system. The influent water of the biochemical treatment unit showed mild acute toxicity and positive in genotoxicity. The total reduction rate of acute toxicity of oil refinery wastewater was 86.514% and the total reduction rate of genotoxicity was 96.221%. The total reduction rate of acute toxicity of chemical wastewater was 53.281% and the total reduction rate of genotoxicity was 62.273%. (2) The TIE results indicated that the main toxic substances in oil refinery wastewater might be cationic metals and non-polar organic substances, and the main toxic substances in chemical wastewater might be cationic metals. (3) Canonical correlation analysis showed that the concentrations of ammonia (r=0.819, p=0.001), Cr (r=0.777, p=0.002) and total petroleum hydrocarbons (TPH) (r=0.752, p=0.002) were positively correlated with the microbial community structure before the biochemical treatment and negatively correlated with the microbial community structure after the biochemical treatment. (4) Microbial functions changed significantly during the biochemical treatment (p≤0.01). The FAPROTAX database predicted a high abundance of microorganisms in the carbon and nitrogen cycling in seven classes: chemoheterotrophy, aerobic chemoheterotrophy, aromatic compound degradation, nitrite respiration, nitrate reduction, nitrate respiration and nitrogen respiration. The study showed that although the biological toxicity along with the processes in the system decreased, the influent water of the biochemical treatment unit was still slightly toxic in acute toxicity and positive in genotoxicity. The characterization of the toxicity suggested that the main toxic substances in oil refinery wastewater were cationic metals and non-polar organic substances, and the main toxic substances in chemical wastewater were cationic metals. The abundance of functional microorganisms involved in carbon and nitrogen cycling in the biochemical treatment unit was high, indicating potential toxic risk in the biochemical treatment unit.