摘要
使用单因素实验,分别考察不同溶液p H、油菜秸秆髓芯加入量、溶液初始Cu^(2+)浓度和吸附时间4个因素对油菜秸秆髓芯吸附水中Cu^(2+)影响作用。采用BBD实验设计分析和优化其吸附条件,并得到最佳吸附条件组合。使用吸附等温方程和动力学方程对其吸附Cu^(2+)过程进行评价,运用红外光谱技术对吸附Cu^(2+)前后油菜秸秆髓芯进行分析,初步推断油菜秸秆髓芯吸附水中Cu^(2+)的机理。最佳吸附条件参数组合:在温度为25℃条件下、初始Cu^(2+)浓度为31 mg/L、溶液p H为5.0和油菜秸秆髓芯加入量为1.17 g/L条件组合下吸附120 min,在此组合条件下油菜秸秆髓芯对水中Cu^(2+)最大去除率达到96.86%。吸附等温方程表明,其吸附Cu^(2+)行为更符合Langmuir方程;动力学方程显示,其吸附Cu^(2+)行为符合二次动力学方程。红外光谱显示,油菜秸秆髓芯中的—C=O、酰胺II基团参与Cu^(2+)的络合吸附。油菜秸秆髓芯对水中Cu^(2+)呈现出良好的吸附性能,为油菜秸秆髓芯作为Cu^(2+)吸附剂提供了应用基础与理论依据。
In this study,the effects of solutions pH,the rape straw core dosages adding,the initial solution Cu^2＋concentration and contact time on adsorption performance of Cu^2＋in aqueous solution with rape straw pith core were investigated and optimized by the methods of single-factor test and Box-Behnken Design in RSM,respectively. The models of adsorption isotherm and kinetic were used to discuss the performance and mechanism of process on removal Cu^2＋from the aqueous with rape straw core. The surface functional groups changes in rape straw core before and after adsorption Cu^2＋were characterized by FT-IR technique. The optimum adsorption conditions were adsorption temperature of 25℃,the initial Cu^2＋concentration of 31 mg/L,solution pH of 4. 33,rape straw core dose of 1. 17 g/L during contact time of 120 min. Under optimal conditions,maximum removal rate of Cu^2＋was 96. 86%. The models of adsorption isotherm and kinetic indicated that the adsorption more fitted with Langmuir isotherm equation and a pseudo-second kinetic. The functional groups of —C=O and amide II rings on the surface of rape straw core played key roles in adsorption process of Cu^2＋. The rape straw pith core presented high adsorption performance of Cu^2＋in aqueous solution,thus it can provide foundation and theoretical basis in future practical operation.
出处
《环境工程学报》
CAS
CSCD
北大核心
2015年第12期5865-5873,共9页
Chinese Journal of Environmental Engineering
基金
四川省教育厅资助科研项目(13ZB0234)
四川省大学生创新训练计划项目(201313705014)
