SBA-15表面修饰及其对水中Cu^(2+)的吸附行为

ADSORPTION BEHAVIORS OF COPPER(Ⅱ) FROM AQUEOUS SOLUTION ONTO FUNCTIONALIZED SBA-15

以3-氨基丙基三甲氧基硅烷为修饰剂,利用修饰方法,制备出氨基修饰SBA-15,并命名为N-SBA-15。采用XRD、FT-IR、N2吸附-脱附对样品进行表征,批量实验研究吸附剂对水中Cu2+的吸附性能,动力学实验数据采用拟一阶动力学方程、拟二阶动力学方程和内扩散方程进行分析。研究结果表明:N-SBA-15对Cu2+的吸附遵循液膜扩散和颗粒内扩散机理,且整个吸附过程更符合拟二阶动力学方程,45℃时Cu2+的最大吸附量达到0.812 mmol/g。Langmuir等温模型可较好地描述Cu2+在N-SBA-15上的吸附行为。热力学研究表明该吸附过程是一个自发、吸热过程,高温有利于吸附。

SBA-15 was functionalized with a post-synthesis method,using 3-aminopropyltrimethoxy-silane as the modifier agent. The functionalized SBA-15 was denoted as N-SBA-15. The samples were characterized by X-ray powder diffraction( XRD),fourier-transform infrared spectroscopy( FT-IR) and N2adsorption-desorption isotherms. The adsorption behavior of the adsorbents on Cu2 +ions was investigated using batch experiments. The kinetic data were analyzed using various kinetic models,such as pseudo-first-order,pseudo-second-order and intra-particle diffusion. The adsorption of Cu( II) onto N-SBA-15 followed the film diffusion kinetics and intra-particle diffusion mechanism. The maximum adsorption capacity of Cu2 +was0. 812 mmol / g at 45 ℃. The pseudo-second-order kinetic model was found to be well suited for the entire adsorption process.Adsorption equilibrium data could be also described well by Langmuir model. Thermodynamic calculations suggested that the adsorption of Cu2 +ions on functionalized-SBA-15 was spontaneous and endothermic and the adsorption was favorable at higher temperatures.