无机-有机柱撑蒙脱石吸附对硝基苯酚的热力学与动力学特征研究

研究了无机-有机柱撑蒙脱石吸附对硝基苯酚的热力学特征,Freundlich和Langmuir等温方程都能较好地描述吸附曲线,所以其吸附机理主要以表面吸附为主;在对硝基苯酚的平衡吸附过程中,焓变ΔH绝对值小于30KJ/mol,表明吸附过程中可能同时存在疏水键力、偶极间力、氢键力、范德华力的作用。比较研究了对硝基苯酚在无机-有机柱撑蒙脱石上吸附的四种动力学模型,在吸附进行前30min,一级动力学方程最为理想,根据其相关系数可以求得各实验温度下的表观吸附速率常数Kd和吸附活化能Ea。

Study on Characteristics of Thermodynamics and Kinetics of p-Nitrophenol Sorption by Inorganic-Organic Pillared Montmorillonite from Water

Inorganic-organic pillared montmorillonite was used to adsorb p-nitrophenol, and the thermo-dynamics and kinetics of sorption process was studied, The sorption isotherms were measured at different temperatures, the functions of thermo-dynamics and kinetics were calculated. During the p-nilrophenol sorption, changing value of enthalpy was bess than 30KJ/mol,which showed Van der Waals forces, hydrophobic bond forces, hydrogen bond forces and dipole bond forces maybe exist. The four kinetic models of p-nitrophenol sorption by inorganic-organic pillared montmorillonite was studied.The result showed that, 30min before sorption, first-order kinetic equation is optimal,and the adsorptive velocity Kd and adsorptive energy Ea can be calculated by relative coefficient under different temperatures.