铁炭微电解还原Cr(Ⅵ)的动力学及其响应面法条件优化

OPTIMIZATION OF CHROMIUM REMOVAL USING RESPONSE SURFACE METHODOLOGY AND ITS KINETICS BY IRON-CARBON MICRO-ELECTROLYSIS

以Cr(VI)模拟废水为研究对象,研究了铁碳微电解过程中溶液p H、铁屑投加量、反应时间、铁碳质量比及溶液初始浓度等因素对处理过程的影响。在单因素实验基础上,以Cr(VI)去除率为考察目标,溶液初始p H、反应时间、铁炭质量比为考察因素,采用Box-Behnken响应曲面法优化了铁炭微电解处理Cr(VI)的工艺条件与拟合二次多项式回归数学模型,分析了3个独立变量之间的交互作用对Cr(VI)去除率的影响。结果表明,当最佳工艺条件p H为2,反应时间为60 min,m(Fe)∶m(C)为2.5时废水中Cr(VI)去除率可达97.85%,与模型预测值96.46%接近,证实了该模型的可靠性。

The effects of initial p H value,dosage of iron,reaction time,rate of iron to carbon and initial concentration of Cr（ Ⅵ） on the removal efficiency of hexavalent chromium by iron-carbon micro-electrolysis were examined in this research.Based on the single factor test,the Box-Behnken response surface methodology was further conducted for mathematical polynomial model and optimization conditions,where the removal efficiency of hexavalent chromium was considered as objective and p H,reaction time and rate of iron to carbon as operational variables. Effects of the independent parameters and their interaction on hexavalent chromium removal efficiency were studied respectively. The optimal conditions for hexavalent chromium removal were found to be p H value of 2. 0,reaction time of 60 min and iron / carbon ratio of 2. 5. The removal efficiency of hexavalent chromium at this optimum condition reached 97. 85%,which was close to the model predictive value of96. 46%,confirmed the reliability of the model.