响应面法优化壳聚糖对混合液镉铬离子吸附条件的研究

doi:10.13386/j.issn1002-0306.2013.11.030

响应面法优化壳聚糖对混合液镉铬离子吸附条件的研究

Study on adsorption of cadmium and chromium ions from the aqueous solution by response surface methodology with chitosan

摘要

摘要: 采用响应面法分析壳聚糖对混合液Cd2+离子和Cr6+离子的吸附作用。用Box-Behnken Design实验设计考察了壳聚糖添加量、重金属初始浓度、pH范围和吸附时间四个因素对壳聚糖去除Cd2+离子和Cr6+离子的影响程度。通过响应面法优化,得到壳聚糖对Cd2+离子和Cr6+离子去除的考察因素条件优化组合参数,即壳聚糖去除Cd2+离子的壳聚糖添加量为26g/L、Cd2+离子初始浓度为319mg/L、pH为6和吸附时间为117min;壳聚糖去除Cr6+离子的壳聚糖添加量为4g/L、Cr6+离子初始浓度为61mg/L、pH为1和吸附时间为360min。在此组合条件下:壳聚糖对Cd2+离子去除率为93.62%,吸附量为12.46mg/g;壳聚糖对Cr6+离子去除率为99.27%,吸附量为10.55mg/g。红外光谱分析显示:壳聚糖中—CH3在结合Cd2+离子中发挥主要作用;—OH、—CH、—NH和—C—O对Cr6+离子结合起主要作用。

Abstract: Response surface methodology was used to investigate the adsorption rate of Cd2+ and Cr6+ions onto chitosan in the aqueous solution. The effect of chitosan amount, initial concentration of heavy metal ions, pH range and adsorption time were investigated to optimize the treatment of Cd2+ and Cr6+ions. This process was analyzed using Box-Behnken Design in RSM. Chitosan loading of 26g/L, initial concentration of Cd2+ ion was 319mg/L, pH of 6 and adsorption time of 117min had been found to be the optimum conditions for the maximum removal ratio of Cd2+ ion in 93. 62% batch mode;Chitosan loading of 4g/L, initial concentration of Cr6+ion was 61mg/L, pH of 1 and adsorption time of 360min had been found to be the optimum conditions for the maximum removal ratio of Cr6+ion in 99. 27% batch mode. Under the above conditions, the Cd2+ and Cr6+ions uptake was attained to be circa 12. 46 and 10. 55mg/g. The Infrared spectroscopy was used to analysis that —CH3group played a important role in binding Cd2+ ion and —OH, —CH, —NH and —C—O groups play important roles in binding Cr6+ion in chitosan.