DHAC改性膨润土对炼油碱渣废液的吸附机理探讨  

Adsorption Mechanism of DHAC Modified Bentonite for Phenols in Petroleum Refining Alkali Dreg Waste Water

作　　者：甄卫军[1] 祁新萍[1] 闵犁园[1] 刘自强[1] 李振江[1] 庞桂林[1] 

机构地区：[1]新疆大学化学化工学院,乌鲁木齐830046

出　　处：《应用化学》2007年第1期80-84,共5页Chinese Journal of Applied Chemistry

基　　金：新疆自治区2003年科技攻关和重点科技项目(200332108)

摘　　要：以有机插层剂双十八烷基二甲基氯化铵(DHAC),对新疆夏子街膨润土进行插层改性,制备DHAC改性膨润土。红外光谱(FTIR)分析表明,双烷基阳离子插层进入蒙脱石片层。X射线衍射(XRD)表明,DHAC改性膨润土片层间距为3．772 nm,为改性前的2．07倍,表明改性后蒙脱土片层间距增大。SEM分析观察, DHAC捕层改性后膨润土颗粒更加疏松,蒙脱石颗粒表面有明显的刻蚀痕迹。通过研究改性膨润土的吸附机理分析表明,DHAC改性膨润土在不同温度下的等温吸附模型符合Freundlich模型,且相关性较高。挥发酚在改性膨润土上的吸附焓值为-2．64 kJ／mol,属于物理吸附,且△Gθ<0,说明该吸附为自发的放热过程。室温下DHAC改性膨润土吸附挥发酚的动力学模型遵循Bingham和Langmuir速率方程。DHAC modified bentonite was prepared starting from Xiazijie bentonite of Xinjiang. FTIR spectra showed that DHAC cation ions were intercalated into the layers of bentonite. It was shown that the layers spacing of the modified bentonite was 3. 772 nm, which is 2. 07 times that of bentonite. SEM images showed that the DHAC modified bentonite particles were looser than that of bentonite, and there were evident erosion trails on the surface of montmorillonite. The isotherm adsorption models of DHAC modified bentonite for volatile phenols was in agreement with Freundlich equation. The adsorption enthalpy of modified bentonite for volatile phenols was -2. 64 kJ/mol, indicating that the adsorption was physical adsorption. Because its △G^θ 〈 0, the adsorption reaction was a spontaneous exothennic process. At the ambient temperature, the adsorption kinetic model of modified bentonite for volatile phenols obeyed Bingham and Langmuir adsorption dynamic models.

关 键 词：膨润土 改性膨润土 炼油碱渣废液 吸附 机理 

分 类 号：O632[理学—高分子化学] X703.1[理学—化学]