复合功能超高交联吸附树脂对氨基萘酚磺酸的静态吸附热力学及动力学特征

Thermodynamics and Kinetics of the Adsorption of Amino-naphthol sulfonic acid onto a New Bi-functional Hypercrosslinked Polymeric Adsorbent

讨论了复合功能超高交联吸附树脂AL 8对氨基萘酚磺酸 (1,2 ,4 酸 )的静态吸附热力学和动力学特征。Freundlich方程能够对静态吸附等温线进行很好的拟合 ,表明为吸热的优惠吸附过程。随着温度的升高 ,吸附量和吸附推动力均增大 ,是“溶剂推动”和“吸附剂推动”效应的综合结果 ,其中后者优势明显。吸附焓变ΔH为 2 8 2 72kJ/mol,表明物理吸附为主兼有较弱的化学吸附以及该吸附剂容易脱附的特征 ;ΔG <0 ,表明吸附的自发性 ;ΔS >0 ,表明更多水分子的脱附现象。颗粒内扩散是速率控制步骤之一 ,膜扩散等也共同影响着吸附过程。

The adsorption property of amino-naphthol-sulfonic acid(1,2,4-acid) onto the bi-functional hypercrosslinked polymeric adsorbent AL-8 based on the polystyrene resin is discussed from the thermodynamic and kinetic viewpoints. A well fitted Freundlich equation is obtained for the adsorption isotherm, indicating an endothermic and a favorable adsorption in the studied range. The capacity and affinity of the adsorption increase with temperature, integrating the phenomena of the ‘sorbent-motivated’ and the more predominant ‘solvent-motivated’ effects. The ΔH value is 28.272 kJ/mol, an indicative of a weakly chemical character and an easier desorption property. The negative value of ΔG indicates the spontaneous nature of the adsorption process, and the positive value of ΔS shows the increased randomness at the solid/solution interface during the adsorption process. Besides the intra-particle diffusion, other processes such as film diffusion also assume the control on the rate of adsorption simultaneously.