印染废水铁碳微电解深度处理出水生物毒性

Toxicity of printing and dyeing wastewater after advanced treatment via ferric-carbon micro-electrolysis

实验利用铁碳微电解对印染废水二级生化出水进行深度处理研究,结果表明,该工艺可使COD从120 mg/L降至60 mg/L以下,达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级B排放标准。通过微生物生长曲线、乳酸脱氢酶(LDH)释放、活性氧物质(ROS)产生水平等检测手段,对比深度处理前后废水的生物毒性。结果表明:印染废水经深度处理后对大肠杆菌的生长抑制明显减弱;进水导致大肠杆菌的LDH释放量和ROS产生水平分别为空白的2.4和28.9倍,深度处理后分别下降至1.8和6.9倍;另外,毒性较大的双酚A和2,4-二氨基甲苯在深度处理过程被降解。可知,铁碳微电解具有毒性削减作用。然而,出水中含有的某些污染物使其仍表现出一定的生物毒性。

Advanced treatment of printing and dyeing wastewater was carried out via the ferric-carbon micro-electrolysis method. Chemical oxygen demand（ COD） was reduced from 120 mg / L to lower than 60 mg / L,meeting the first discharge standard B of the Discharge Standard of Pollutants for Municipal Wastewater Treatment plant（ GB 18918-2002）. Biological toxicity of the printing and dyeing wastewater before and after advanced treatment were compared based on the microbial growth curve,lactate dehydrogenase（ LDH） release,and reactive oxygen species（ ROS） production. The inhibition of Escherichia coli growth decreased significantly after advanced treatment. LDH release and ROS production induced by the influent were 1. 4 and 27. 9 times higher than that of the control test; however,they decreased to 1. 8 and 6. 9 times that of the control test after advanced treatment. In addition,the pollutants bisphenol A and 2,4-diaminotoluene,which exhibit high toxicity,were degraded during the advanced treatment process. Therefore,these results clearly established that advanced treatment via ferric-carbon micro-electrolysis is effective with respect to toxicity reduction. However,the effluent still showed some toxicity owing to tiny pollutants.