不同层间堆垛密度的HDTMA^+柱撑蒙脱石对对硝基苯酚的吸附实验研究  

The sorption of p-nitrophenol from aqueous solutions on the HDTMA^+-pillared montmorillonites with different interlayer packing densities

作　　者：周琴[1] 何宏平[1] 袁鹏[1] 

机构地区：[1]中国科学院广州地球化学研究所

出　　处：《岩石矿物学杂志》2005年第6期568-572,共5页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(40372029);广东省自然科学基金资助项目(030471)

摘　　要：本文以阳离子表面活性剂(十六烷基三甲基溴化铵,HDTMAB)为柱撑剂,在不同浓度条件下(0.5～2.5CEC)制备了层间季铵盐离子呈单层平卧、双层平卧和倾斜双层排列的HDTMA+柱撑蒙脱石,并研究了具有不同层间结构的HDTMA+柱撑蒙脱石对对硝基苯酚的吸附能力以及溶液pH值、温度、对硝基苯酚初始浓度等因素对HDTMA+柱撑蒙脱石吸附性能的影响。实验结果表明,HDTMA+柱撑蒙脱石对对硝基苯酚的吸附能力随着介质溶液pH值的升高而升高,这主要受对硝基苯酚在不同pH条件下的离子化程度影响;HDTMA+柱撑蒙脱石对对硝基苯酚的吸附能力随着介质溶液温度的升高而降低,说明吸附反应是一个放热过程。同时,从单层平卧→双层平卧→倾斜双层,HDTMA+柱撑蒙脱石对对硝基苯酚的吸附能力明显提高。钠基蒙脱石和低堆垛密度(单层平卧、双层平卧)的HDTMA+柱撑蒙脱石对对硝基苯酚的吸附等温线呈S型,而高堆垛密度(倾斜双层)的HDTMA+柱撑蒙脱石对对硝基苯酚的吸附等温线呈Linear型,表明前者以表面吸附为主,后者以分配作用为主。HDTMA^＋ -pillared montmorillonites with surfactant arrangements of lateral-monolayer, lateral-bilayer and paraffin-bilayer, respectively, were prepared at different concentrations （0.5- 2.5 CEC） of hexadecyltrimethylammoniurn bromide （HDTMAB）. The sorption properties of the resultant organoclays were tested using p-nitrophenol as a model pollutant. The sorption efficiency of the organoclays increases with the increase of the solution pH, depending on the ionization extent of p-nitrophenol, whereas the sorp- tion efficiency decreases with the increase of solution temperature, suggesting that the sorption reaction is exothermic. Generally, the sorption efficiency of organoclays increases with the increase of the surfactant packing density within montmorillonite interlayer, i.e., in the order of lateral-monolayer, lateral-bilayer and paraffin-bilayer. The isotherms for Na-montmorillonite, organoclays with lateral- monolayer and lateral-bilayer arrangements display S-type, implying that p-nitrophenol is mainly adsorbed on clay surfaces. For organoclays with paraffin-bilayer arrangement of the confined surfactants, their isotherms belong to Linear-type, demonstrating that p-nitrophenol enters the clay interlayer.

关 键 词：HDTMA+柱撑蒙脱石 层间堆垛密度 对硝基苯酚 吸附 

分 类 号：P579[天文地球—矿物学] X703[天文地球—地质学]