有机物在水/双阳离子有机膨润土界面的吸附贡献率研究

在长、短碳链表面活性剂总量恒定条件下制备了一系列双阳离子有机膨润土，研究了其对水中苯胺，对硝基苯酚2，4－二氯酚的吸附行为，结果表明双阳离子有机膨润土对有机物的分配系数（Kd）与有机碳含量（f∝)、辛醇－水分配系数（lgKow)成线性正相关，与溶解度（lgS)成线性负相关，通过数学模拟，首次描述了表面吸附和分配作用两种吸附机制的相对贡献率和改性表面活性剂配比的关系；结果表明双阳离子有机膨润土对水中有机物两种吸附机制的主导地位与有机物本身性质有关，其主导作用发生变化的拐点与长碳链表面活性剂所占比重相关。

Contributions of adsorption and partition to the total sorption of organic compounds on the interface of water and dual-cation organobentonites

A series of dual-cation organobentonites were synthesized by replacing the metal ions in bentonite with both long-chain alkyl quaternary ammonium cation, such as cetyltrimethylammonium(CTMAB), and short-chain alkyl quaternary ammonium cation, such as tetramethylammonium (TMAB). Keeping the total amount of surfactants unchanged and the ratio of CTMAB to TMAB being changed, the sorption behavior for dual-cation organobentonites to sorb aniline, p-nitrophenol, 2, 4-dichlorophenol from water was investigated. The results show that the organic pollutant distribution coefficients (Kd) between dual-cation organobentonites and water are positively proportional to the organic carbon content of organobentonites (f ) and lgK0w but negatively proportional to their solubility (Ig5). The separate contributions of adsorption and partition to the total sorption of organic compounds on the interface of water and dual-cation organobentonites were analyzed quantitatively. It is suggested that the dominant status of adsorption and partition is related to the property of organic compounds and the proportion of the long-chain alkyl quaternary ammonium cation.