Box-Behnken响应曲面优化铁炭微电解降解结晶紫

Process optimization for degradation of crystal violet by ferric-carbon micro-electrolysis using Box-Behnken response surface methodology

在单因素实验的基础上,以结晶紫脱色率为评价指标,铁炭比、反应时间与曝气量为考察因素,采用Box-Be-hnken响应曲面法优化铁炭微电解降解结晶紫的工艺条件,同时得出相应的数学模型。实验表明,在结晶紫初始浓度为100mg/L和体积为300 mL,pH为3,反应时间为80 min,铁屑的投加量为20 g,铁炭质量比为2∶1,曝气量为20 L/h的条件下,铁炭微电解对结晶紫的脱色率可达到89.6%。通过Box-Behnken响应曲面可知,铁炭比、反应时间、曝气量以及铁炭比和反应时间的交互作用对结晶紫的脱色率均有显著影响,其中曝气量对脱色率的影响尤为显著;回归模型决定系数R2=0.9067,P=0.039,表明此模型拟合程度良好,且模型显著。铁炭微电解降解结晶紫最佳的工艺条件为:铁炭比为2.4∶1,反应时间为84 min、曝气量为40 L/h,脱色率为93.25%,回归模型的预测值与测定值偏差率为2.26%。

Base on the single factor test, the Box-Behnken response surface methodology was utilized for modeling and optimization conditions on degradation of crystal violet by ferric-carbon micro-electrolysis. In this case, decolorization rate was selected as one response value, while the ratio of ferric to carbon, aeration rate and reaction time were considered as influential factors. At the same time, the mathematical model was established between the decolorization rate and the three influential factors. The results showed that when the initial concen- tration was 100 mg/L and volume was 300 mL, the decolorization rate could reach 89.6% with the ratio of ferric to carbon of 2： 1, the aeration rate of 20 L/h, the dosage of ferric of 20 g, the pH of 3 and the reaction time of 80 min. The ratio of ferric to carbon, aeration rate, reaction time, the interaction of ratio of ferric to carbon and reaction time were all significant factors. Especially, the aeration rate on the decolorization rate was particularly significant. The determinate coefficient of model was 0. 9067 and the probability p value was 0. 039. It showed that the model fitting degree was good, and the model was significant. The optimum conditions were as follows： the ratio of ferric to carbon of 2.4： 1, aeration rate of 40 L/h and reaction time of 84 rain. Under such condi- tions, the decolorization rate was 93.25% and the error of the model-predicted and experimental values of decol- orization rate was 2.26%.