响应面法优化紫外激活过硫酸盐降解莠灭净

Degradation of Ametryn by UV Activated Persulfate:Optimization by Response Surface Methodology

基于Box-Behnken响应面法对紫外(UV)激活过硫酸盐(PS)降解莠灭净(AMT)工艺进行优化。考察了底物初始浓度(4~20)μmol·L^(-1),p H(3~9),溶液中Cl^-浓度(20~180)mmol·L^(-1)三因素对AMT降解的准一级动力学表观速率常数kobs的影响。响应面分析表明kobs与三因素关系符合二次多项式模型。初始底物浓度和p H的一次项和二次项、Cl^-浓度的一次项、初始底物浓度和p H以及初始底物浓度和Cl-浓度的交互作用对kobs具有显著影响。通过优化得到最佳工艺参数为:底物初始浓度为4μmol·L^(-1),初始p H为6.88,Cl^-浓度为20 mmol·L^(-1),该条件下,进行三次重复试验,kobs为0.047 7,与预测值0.050接近,表明响应面模型与实际情况吻合。

Response surface methodology of Box-Behnken was used for optimizing the degradation of Ametryn （AMT） by UV activated persulfate （PS）. The effect of initial substrate concentration （4-20） μmol·L^-1, initial pH （3-9） and the Cl^- concentration （20-180）mmol·L^-1 for the kob, of AMT was investigated. The quadratic formula was obtained by response surface analysis between the kobs and the three parameters. The linear and quadratic term of initial substrate concentration and pH, the linear term of Cl^- concentration and the interaction between initial substrate concentration and pH, initial substrate concentration and Cl^- concentration have significant effects on the kob. The optimum process parameters were determined to be 4 μmol·L^-1 AMT,pH 6. 88 and 20 mmol·L^-1 Cl^-. Under these conditions,the kobs in three replicated experiments was 0. 047 7, and this value was not significantly different from the value of 0. 050 predicted by the model. It confirmed that the statistic model is consistent with the actual situation.