Box-Behnken响应曲面法优化草酸改性杨树叶对六价铬的吸附

Process optimization of hexavalent chromium absorption onto Poplar leaves modified by oxalate using Box-Behnken response surface methodology

采用草酸改性杨树叶(OPL)作为新型生物吸附剂对水溶液中六价铬[Cr(Ⅵ)]进行吸附,探讨了影响吸附效果的主要因素,并利用Box-Behnken响应曲面法对吸附条件进行优化。单一因素实验结果表明,溶液pH、吸附剂投加量和Cr(Ⅵ)离子初始质量浓度对Cr(Ⅵ)在生物吸附剂OPL表面的吸附产生较大影响。Box-Behnken响应曲面法对吸附条件的优化结果表明,当pH为1.66、投加量为0.29g、Cr(Ⅵ)初始质量浓度为50mg/L时,生物吸附剂OPL对Cr(Ⅵ)的吸附效果最好,预测去除率为99.98%,与实测去除率仅偏差4.8%。

Poplar leaves modified by oxalate was used to remove hexavalent chromium from aqueous solution.The main factor affecting the removal of hexavalent chromium was discussed and the optimize adsorption condition was determined by the Box-Behnken response surface methodology.The experiment result of single factor showed that the solution pH,adsorbate dosage and initial hexavalent chromium concentration had great influence on the hexavalent chromium adsorption onto poplar leaves modified by oxalate.Box-Behnken response surface methodology was conducted to predict the optimal adsorption condition.The result indicated that when the pH was 1.66,adsorbate dosage was 0.29 g and the initial concentration of the hexavalent chromium was 50mg/L,the adsorption ratio of hexavalent chromium by modified Poplar leaves was predicted to be 99.98%.The deviation between predicated remove rate and measured remove rate was only4.8%.