响应面法优化硫酸根自由基降解对氯苯酚

摘要

利用响应面法(RSM)对原位掺硫活性炭活化过硫酸盐生成硫酸根自由基(SO-4·)降解对氯苯酚进行了研究.选择溶液初始pH值、反应温度及过硫酸钾/对氯苯酚物质的量比为考察因素,对氯苯酚拟一级降解速率常数(Y)为响应值,通过Box-Behnken设计方法(BBD)建立了以对氯苯酚拟一级降解速率常数为响应值的二次多项式模型,分析了各因素及其相互作用对拟一级降解速率常数的影响,确定了最佳反应条件.结果表明:所选取的3个因素中温度对拟一级降解速率常数的影响最为显著,且最佳反应温度为55℃,过硫酸钾/对氯苯酚物质的量比为25.64,溶液初始pH值为4.51.在该条件下,对氯苯酚拟一级降解速率常数的试验值为0.19294 min-1,与模型预测值偏差0.00326 min-1,说明响应面方法能够有效优化对氯苯酚的降解条件.%The degradation of 4-chlorophenol by SO-4· generated from persulfate activated by in situ S-doped carbon was studied by using response surface methodology (RSM).Box-Behnken design (BBD)was applied to establish a quadratic model describing pseudo-first-order degradation rate constant of 4-chlorophenol (Y )obtained at different levels of critical parameters,namely ini-tial pH of solution,reaction temperature and persulfate/4-chlorophenol molar ratio.The influ-ence of the parameters and their interaction on Y was discussed.Model results reveal that reac-tion temperature showed the most remarkable effect onY and the optimum conditions were as fol-lows:initial solution pH of 4.51,reaction temperature of 55 ℃ and persulfate/4-chlorophenol molar ratio of 25.64.Under the optimum operating condition,the observed value of Y was 0.19294 min-1 ,which showed a deviation of 0.00326 min-1 from the predicted value,indicating the good applicability and feasibility of RSM for optimizing reaction conditions for 4-chlorophenol degradation.