CTAB改性的蒙脱石对酚类污染物吸附性能的研究  

Adsorption performance of CTAB modified montmorillonite for phenolic pollutants

作　　者：李慎敏[1] 刘红岩 崔颖娜 尹静梅[1] LI Shenmin;LIU Hongyan;CUI Yingna;YIN Jingmei(Liaoning Key Laboratory of Bio-organic Chemistry,Dalian University,Dalian 116622,China)

机构地区：[1]大连大学辽宁省生物有机化学重点实验室,辽宁大连116622

出　　处：《辽宁师范大学学报（自然科学版）》2022年第3期352-361,共10页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(21133005);大连市高层次人才项目(2016RJ11)。

摘　　要：通过水热法制备了十六烷基三甲基溴化铵(CTAB)改性的蒙脱石吸附剂.使用XRD和BET方法对改性前后蒙脱石层间距离、比表面积及孔隙体积进行了表征,表征结果显示,CTAB成功进入蒙脱石层间,使蒙脱石层间距增大,比表面积和总孔隙体积减小.使用改性前后的蒙脱石对水中的苯酚、2-氯苯酚(2-CP)、2,4-二氯苯酚(2,4-DCP)进行吸附实验,探索吸附时间、含酚溶液pH、酚初始浓度等因素对吸附性能的影响.研究表明,蒙脱石有机改性后对三种酚类化合物有较强的吸附能力,对苯酚,2-CP及2,4-DCP的单位最大吸附量分别为22.44、91.80、150.16 mg/g.三种酚类化合物在改性蒙脱石上的吸附是一个快速过程,而且在pH小于各自的pKa时吸附效果最好.改性蒙脱石对酚的吸附效率提升主要是季铵盐的增溶作用导致的,与吸附剂的比表面积与孔隙大小关系不大,吸附过程符合Langmuir等温吸附模型和准二级动力学方程.经过5次再生后,改性蒙脱石对3种酚类化合物仍具有较好的吸附性能.The hydrothermal method was used to prepare adsorbent of montmorillonite modified by hexadecyl trimethyl ammonium bromide(CTAB).The interlayer space of modified montmorillonite was characterized by X-ray diffraction(XRD)and the specific surface areas were determined with the Brunauer-Emmett-Teller(BET)equation using nitrogen as the adsorbate.Furthermore,the adsorption experiments of phenol,2-chlorophenol(2-CP),2,4-dichlorophenol(2,4-DCP)in water were conducted to explore the influence of time,pH value,initial concentration and other factors on the adsorption performance.The results showed that with inserting of CTAB to montmorillonite,the interlayer space increased,while the specific surface area and total volume of pores decreased.The adsorption performance of modified montmorillonite for the three phenolic compounds was significantly improved,the maximum adsorption capacity per unit of phenol,2-CP and 2,4-DCP were 22.44,91.80 and 150.16 mg/g,respectively.The adsorption performance for the three phenolic compounds was the best when the pH value was lower than their respective isoelectric points.The improvement of the adsorption efficiency of the modified montmorillonite for phenol is mainly caused by the solubilization effect of the quaternary ammonium salt,which has little to do with the specific surface area and pore size of the adsorbent.The adsorption process was a rapid process,which was in accordance with Langmuir isothermal adsorption model and obeyed to quasi-second-order kinetic equation.After 5 times of regeneration,the modified montmorillonite still has good adsorption performance for the three phenolic compounds.

关 键 词：有机改性蒙脱石 十六烷基三甲基溴化铵(CTAB) 吸附 酚类化合物 

分 类 号：O647.3[理学—物理化学] X703[理学—化学]