超声波协同Fenton氧化降解PVA及其动力学分析

摘要

采用超声波协同Fenton氧化降解聚乙烯醇(PVA)模拟废水,并与2种方法单独作用进行了对比.结果表明,增加反应时间和超声功率在一定程度上有助于提高PVA的去除率;反应的最佳pH应该控制在4.0左右;随着H2O2/COD(质量浓度比)的增加,PVA去除率有很大提高,H2O2/Fe2+(物质的量比)最佳值为8.通过分析不同反应时间下降解产物分子质量分布情况和GC-MS检测结果,推测反应将大分子氧化成中小分子的过程.动力学分析结果表明,超声波协同Fenton降解PVA符合一级反应动力学规律,从k值模型方程可看出H2O2/COD对反应的影响最大.%The combination of ultrasonic with Fenton oxidation is used to treat PVA simulated wastewater and com-pare with the two methods alone for wastewater treatment. The experimental results show that the increase of reaction time and ultrasonic power contributes to increasing the removal rate of PVA to a certain extent ,the optimal pH for ultrasonic Fenton reaction should be controlled at about 4.0,with the increase of H2O2/COD ratio,the removal rate of PVA is greatly improved,and the optimal value of H2O2/Fe2+is 8. The process of macromolecules degradation to small molecules is deduced by analyzing the changes in the molecular weight distribution of degradation products under di-fferent reaction times and the results of GC-MS detection. Kinetic analysis showed that the degradation process con-forms to the first-order reaction kinetics. It can be seen from the k-value model equation that H2O2/COD has the great-est influence on the reaction.