Fenton法处理印染废水的特性及动力学研究

The Study of Characteristic and Kinetics on Treatment of Printing and Dyeing Wastewater by Fenton Method

针对印染废水水质复杂、处理难度高的问题,研究采用Fenton法对印染废水进行处理.考察pH、Fe^(2+)投加量、H_2O_2/Fe^(2+)摩尔比、反应时间等因素对污染物去除率的影响,分析污染物质官能团的变化,建立污染物降解动力学模型.结果表明:在pH值为2.5、Fe^(2+)投加量为5 mmol、H_2O_2/Fe^(2+)摩尔比为4、反应时间为50 min时,污染物去除效果最好,色度、TOC、COD和氨氮的去除率可达99.8%、85.11%、90.69%和66.63%;通过分析UV-vis吸收谱图、HPLC谱图、GC-MS谱图的变化,证明发色官能团被氧化降解.建立了底物降解速率与底物浓度、H_2O_2浓度和Fe^(2+)浓度相关的催化降解动力学模型,其中底物浓度的反应分级数(m=0.265)高于Fe^(2+)的反应分级数(q=-1.48),表明底物浓度对Fenton的氧化降解过程影响较大.

In view of the complexity of printing and dyeing wastewater and the difficulty of dealing with it,Fenton method was used to oxidize and degrade printing and dyeing wastewater in this study.The effect of pH,Fe^2+,H 2O2/Fe^2+ molar ratio and reaction time on the degradation rate of pollutants were investigated.The organofunctional changes of pollutants were analyzed and degradation kinetic model of pollutants was established.The results showed that under the conditions of pH 2.5,Fe^2+ of 5 mmol/L,H 2 O2/Fe^2+ molar ratio of 4 and reaction time of 50 min,the removal efficiency of colorimetric,TOC,COD and ammonia nitrogen were the highest and achieved 99.8%,85.11%,90.69% and 66.63%,respectively.The color functional groups were oxidized and degraded by analyzing the changes of UV-vis absorption spectra,HPLC spectra and GC-MS.The dynamic model of catalytic degradation among substrate degradation rate,substrate concentration,Fe^2+ concentration and H2O2 concentration was established.The ranked reaction series of the substrate concentration ( m =0.265) was higher than that of Fe^2+(q=1.48),which could prove that the influence of substrate concentration on Fenton oxidation degradation process was greater.