作　　者： ; ; ; ; ; ;

机构地区： 华南理工大学

出　　处： 《环境科学》 2013年第7期2686-2693,共8页

摘　　要： 插层法制备有机黏土存在比表面积低、负载不均等问题,限制了此类材料吸附性能的进一步提高.基于此,通过选择性酸浸的方法预处理天然蛭石,以三甲基氯硅烷(CTMS)和三乙基氯硅烷(CTES)对其进行表面有机修饰,利用FTIR、BET、SEM和热重等方法对材料进行表征.结果表明,改性酸化蛭石的比表面积可达361.0 m2.g-1,而有机插层蛭石的比表面积仅为6.0m2.g-1,有机基团更稳定地以共价键形式负载于酸化蛭石表面.以疏水性有机微污染物邻苯二甲酸二乙酯(DEP)为测试目标,考察材料的吸附性能.在本实验条件下,测得CTES改性酸化蛭石、CTMS改性酸化蛭石和有机插层蛭石对DEP的吸附量分别为63.7、51.2和15.7 mg.g-1,证明有机修饰后的酸化蛭石具有更强的疏水性吸附能力,有机负载的均匀性是决定吸附能力的关键因子.动力学研究表明吸附行为遵循拟二级动力学方程;吸附等温线表现出线性特征,可由Henry和Freundlich模型进行描述,表明分配作用是吸附过程的主要机制. To solve the problems of intercalated organoclay such as low surface area and inhomogeneous organic loading, natural vermiculite was activated by acid leaching and then modified by trimethylchlorosilane （CTMS） and triethylchlorosilane （CTES）. The modified materials were characterized by FTIR, BET, SEM and TG. Experimental results indicated that the surface area of the modified acid vermiculite （361.0 m2·g-1） was much larger than that of the intercalated organovermiculite （6.0 m2·g-1）, moreover, the organic groups were grafted onto the surface covalently. Diethyl phthalate （DEP）, a typical hydrophobic micro-organic pollutant, was used to test the adsorption capacity of different adsorbents. The adsorption amounts of DEP were 63.7, 51.2 and 15.7 mg·g-1 for CTES, CTMS and intercalated organovermiculite in this study, respectively. The high organic affinity of modified acid vermiculite was due to both the bigger surface area and the homogeneous organic loading. The adsorption kinetics was found to follow the pseudo-second-order model. The isotherms exhibited linear characteristics and could be described by Henry and Freundlich equations, indicating that the partition process is the main control mechanism of the removal of DEP.

关 键 词： 黏土 酸化蛭石 有机改性 吸附 邻苯二甲酸二乙酯

领　　域： [环境科学与工程]