羧基功能化榴莲壳对水中Pb(Ⅱ)和Cr(Ⅲ)的生物吸附研究  

Biosorption of Pb(Ⅱ)and Cr(Ⅲ)from aqueous solutions by carboxyl-functionalized durian shell

作　　者：吴文炳[1,2] 李晓[2] 张卫英[2] 陈建华[1] 

机构地区：[1]闽南师范大学化学与环境学院,福建漳州363000 [2]福州大学石油化工学院,福州350108

出　　处：《功能材料》2015年第22期22037-22044,共8页Journal of Functional Materials

基　　金：福建省自然科学基金资助项目(2014J01204);福建省教育厅科技计划资助项目(JA12215);漳州市自然科学基金资助项目(ZZ2013J05)

摘　　要：研究了柠檬酸改性榴莲壳对水中Pb(Ⅱ)和Cr(Ⅲ)的吸附效果、动力学与等温吸附特性。通过SEM、FT-IR和XPS表征测试,分析榴莲壳改性前后的特征变化,并探讨榴莲壳的改性和吸附机理。表征分析发现,以N,N’-羰基二咪唑为活性剂进行榴莲壳表面改性后,在1 730和1 640cm-1处分别出现明显的酯羰基和自由羧基吸收峰,且改性后m(O)/m(C)原子质量比明显增大,说明柠檬酸成功接枝到榴莲壳表面。吸附实验结果表明,榴莲壳经改性后对Pb(Ⅱ)和Cr(Ⅲ)的吸附量有明显地提高,分别是未改性榴莲壳的3.15和2.42倍,且当两种金属离子共存时,Pb(Ⅱ)的竞争吸附优于Cr(Ⅲ)。动力学研究显示,改性榴莲壳吸附Pb(Ⅱ)和Cr(Ⅲ)在120min内达到平衡,实验数据符合准二级动力学模型(R2>0.9975)。在25℃下,等温吸附过程可采用Freundlich模型(R2>0.9902)进行拟合。吸附-解吸实验表明,CM-CDIDRS对Pb(Ⅱ)进行4次吸附再生循环后仍能保持较高吸附能力。The adsorption efficiency,isothermal adsorption and kinetics of durian shell modified by citric acid for Pb(Ⅱ)and Cr(Ⅲ)from aqueous solution was investigated.Both modified and unmodified adsorbents were characterized by FT-IR,SEM and XPS,and modification and adsorption mechanism of durian shell was discussed.The results of FT-IR and XPS demonstrated that after modified by citric acid via N,N'-carbonyldiimidazole as a activator,the new peaks at 1 730 and 1 640cm-1 were assigned to ester carbonyl groups and carboxylate stretching band on durian shell and the m(O)/m(C)atom mass ratio increased,which indicated the presence of citric acid grafted onto durian shell.Adsorption results showed that,the adsorption capacity of durian shell modified by citric acid for Pb(Ⅱ)and Cr(Ⅲ)were 3.15 and 2.42 times as those of the natural durian shell,respectively.The adsorption of Pb(Ⅱ)on durian shell modified by citric acid exhibited a stronger competitive effect than Cr(Ⅲ)in the aqueous solution with two coexisting anions.The adsorption kinetics data showed that the adsorption equibrium was reached in 120 min for Pb(Ⅱ)and Cr(Ⅲ)and the data of adsorption rate could be described by pseudo-second-order rate model(R2>0.9975).At 25 degrees celsius,the isothermal adsorption of Pb(Ⅱ)and Cr(Ⅲ)on durian shell modified by citric acid tended to be fitted well by the Freundlich model(R2>0.9902).Adsorption-desorption results showed that the CM-CDI-DRS remained high biosorption ability for Pb(Ⅱ)after four-time usage.

关 键 词：榴莲壳 柠檬酸 重金属 动力学 等温吸附 

分 类 号：X703[环境科学与工程—环境工程]