偏苯三酸酐修饰的吸附树脂对苯酚和对硝基苯酚的吸附研究

Adsorption of phenol and p-nitrophenol onto trimellitic anhydride modified hyper-crosslinked adsorption resin

通过后交联及化学修饰反应制备了偏苯三酸酐修饰的超高交联吸附树脂(TMA),研究了TMA树脂对苯酚和对硝基苯酚的吸附行为。结果表明,TMA树脂具有较高的比表面积和较丰富的微孔,对苯酚和对硝基苯酚均具有较好的吸附性能,且吸附过程为典型的物理吸附,其等量吸附焓变、自由能变和熵变均为负值。Langmuir和Freundlich等温方程均能较好地拟合苯酚和对硝基苯酚在TMA树脂上的吸附等温线。吸附动力学过程符合准一级动力学方程,颗粒内扩散过程是TMA树脂吸附苯酚和对硝基苯酚的主要控制步骤。

A new hyper-crosslinked resin （TMA） modified with trimellitic anhydride was prepared by post-crosslinking of chloromethyl low crosslinking macroporous poly-styrene and chemical modification. The adsorption performance and mechanism of TMA for phenol and p-nitrophenol were studied through the isotherm adsorption and batch kinetics experiments. The results showed that TMA had good adsorption capabilities to phenol and p-nitrophenol because of the high specific surface area and relatively abundant micropore distribution. The adsorption of phenol and p-nitrophenol on TMA was an exothermic typical physical adsorption process which was in accordance with both Langmuir and Freundlich isotherm equation. Quasi-first kinetic adsorption equation could describe the adsorption dynamics behavior perfectly, which meant inner diffusion of the particles was the major controlling step of adsorption process.