D201树脂吸附SO42-的动力学、热力学特性及表征分析

Adsorption Kinetics and Thermodynamics of SO42- on D201 Resin and Characterization Analysis

摘要:

将国产D201大孔强碱性苯乙烯系阴离子交换树脂应用于废水中SO42-吸附脱除，分析其吸附动力学和热力学特性，并通过X-射线衍射、红外光谱和扫描电镜等分析手段对吸附前后的树脂进行表征，对吸附机理进行了探讨。结果表明，吸附过程符合准二级动力学模型，理论平衡吸附量qe'=63.291 mg/g (实际qe=62.585 mg/g)，过程控速步骤为液膜扩散，液膜扩散常数k=0.1623，可通过加速搅拌或增大树脂的孔径来获得更快的反应速度；Langmuir吸附等温式拟合度更好，D201对SO42-的吸附作用为单分子层吸附，且为优惠吸附，吸附过程为吸热过程；D201为非晶态物质，表面带有很大活性，存有很多的微细孔和大网孔，饱和吸附后孔道更加清晰，表面更加平整，且结构中出现磺酸基 SO3H— 特征峰，为SO42-与D201树脂季铵基[—N(CH3)3OH]反应的结果。

Abstract:

The D201 macroreticular polystyrene strong base ion exchange resin was applied to SO42 - adsorption removal from wastewater, which adsorption kinetics and thermodynamic were analyzed. The resins before and after adsorption were characterized by XRD, FTIR and SEM, the adsorption mechanism was also discussed. The results show that the adsorption process conforms to the pseudo-second order kinetic model, qe'= 63.291 mg/g (qe= 62.585 mg/g), liquid film diffusion is the controlling step, and the diffusion constant is 0.1623, rapid agitation or bigger bore diameter of resin can obtain faster response speed; Langmuir isotherm fits better to the adsorption behavior, which is monolayer adsorption and favorable adsorption for D201 resin, the adsorption process is endothermic process; the characterization shows that D201 resin is amorphous substance with much activity and many micro- and macro-pores on the surface, and became more clear and smooth after adsorption. The characteristic peak of SO3H— also appeared, as a result of the reaction of SO42-and [—N(CH3)3OH] on D201 resin.