BBD法优化固定填料床曝气去除水中氯代烷烃

Optimization of Fixed Packed Bed Aeration Process by Box-Behnken Design( BBD) Method for Removal of Chlorinated Hydrocarbons from Water

采用Box-Behnken Design(BBD)法进行了固定填料床曝气工艺去除水中氯代烷烃的中心组合试验,以三氯甲烷、四氯化碳为例,研究了气水比、进水流量、初始浓度对污染物去除率的影响。试验结果表明,上述3个因素对三氯甲烷去除率有较为显著的影响,而对四氯化碳去除率的影响很小。建立的两种污染物回归模型与实际试验结果均拟合较好,具有统计学意义。上述3个因素对三氯甲烷去除率影响的交互作用较四氯化碳明显,因此重点分析了对三氯甲烷去除效果的交互作用。对于三氯甲烷以及四氯化碳而言,当气水比分别为15和14、进水流量分别为2和4.8 L/min、初始浓度分别为0.258和0.0092 mg/L时为最优工况,此时模型预测的去除率分别为89.8%、100%,二者误差均在可接受范围内。

Box-Behnken Design(BBD)method was used to carry out the central composite test of removing chlorinated hydrocarbons from water by fixed packed bed aeration process.Effects of gas-water ratio,influent flow rate and initial concentration on removal rates of chloroform and carbon tetrachloride were investigated.The results showed that the above three factors had a significant effect on the removal rate of chloroform.However,they had little effect on the removal rate of carbon tetrachloride.The established regression models of the two pollutants fitted well with the actual test results and had statistical significance.The interaction effect of the above three factors on the removal rate of chloroform was more obvious than that of carbon tetrachloride,and the interaction effect of chloroform removal was emphatically analyzed.The optimum operational conditions of chloroform removal were gas-water ratio of 15,influent flow rate of 2 L/min and initial concentration of 0.258 mg/L,respectively,and those of carbon tetrachloride removal were 14,4.8 L/min and 0.0092 mg/L,respectively.In these circumstances,the removal rates predicted by the model were 89.8%and 100%,respectively,and both errors were within the acceptable range.