铁碳微电解处理印染废水的效能及生物毒性变化

为了提高铁碳微电解工艺处理实际印染废水的效率，采用响应面法进行工艺条件优化。以COD去除率为响应值，初始pH、铁投加量、铁碳质量比及反应时间为实验因素，构建响应面模型，分析模型的显著性。结果表明：当初始pH为3.53、铁投加量为83.92g/L、铁碳质量比为0.82及反应时间为78.48min时，COD去除率的预测值为75.25%，与实测值相差0.23%（＜2%），可以利用该模型预测COD去除率的变化。同时采用大肠杆菌对铁碳微电解工艺进出水的生物毒性进行检测，与进水组相比，出水组中乳酸脱氢酶（LDH）释放量由对照组的2.13倍下降至对照组的1.64倍，同时活性氧物质（ROS）产生水平由对照组的19.26倍下降至对照组的4.81倍，细胞死亡率由98.1%下降至61.5%，对数期由5h延长至9h，且BOD₅/COD从0.151升至0.416，因此铁碳微电解工艺具有降低印染废水生物毒性的作用。

Efficiency and biological toxicity of iron-carbon microelectrolysis in treatment of the dye wastewater

In order to improve the efficiency of the actual dye wastewater treatment by the iron-carbon micro-electrolysis process, the response surface method was used to optimize the process conditions. A response surface model was constructed and the significance of the model was analyzed when removal efficiency of COD was used as response value and initial pH, iron dosage, iron-carbon mass ratio and reaction time were used as experimental factors. The results showed that when the initial pH was 3.53, the iron dosage was 83.92g/L, the iron-carbon mass ratio was 0.82 and the reaction time was 78.48min, the predicted COD removal efficiency was 75.25%. The deviation was 0.23% (＜2%) compared with the measured value. The model can be used to predict the change of COD removal efficiency. The biotoxicity of the influent and effluent in the iron-carbon microelectrolysis process was tested by E.coli. Compared with the influent group, the release of lactate dehydrogenase (LDH) in the effluent group decreased from 2.13 times to 1.64 times in the control group, while the production of reactive oxygen species (ROS) decreased from 19.26 times to 4.81 times in the control group. The cell death rate decreased from 98.1% to 61.5%, and the growth phase was extended from 5h to 9h, and the BOD₅/COD rose from 0.151 to 0.416. Therefore, the iron-carbon microelectrolysis process has the effect of reducing the biological toxicity of dye wastewater.