苯胺-2,4-二氨基酚共聚物吸附水中Hg(Ⅱ)的动力学和热力学研究

KINETICS AND THERMODYNAMICS OF Hg(Ⅱ) ADSORPTION ONTO POLY(ANILINE-CO-2,4-DIAMINOPHENOL)

利用化学氧化法合成苯胺-2,4-二氨基酚共聚物,通过静态吸附实验研究了该共聚物吸附水中汞离子的动力学和热力学.对实验数据采用准一级和准二级动力学方程、Langmuir等温线方程、Freundlich等温线方程进行拟合,并进行相应的热力学分析.研究结果表明,苯胺-2,4-二氨基酚共聚物对水中Hg(Ⅱ)具有很好的去除效果,最大吸附容量达800mg·g-1,吸附等温线符合Langmuir单层吸附模型;动力学过程符合准二级动力学模型;吸附焓变化量ΔH=58.51kJ·mol-1,表明该吸附反应为化学吸附且为吸热反应;三种实验温度下吉布斯自由能变化量均为负值,表明该吸附反应能自发进行。

A batch method was used to investigate the kinetics and thermodynamics of Hg（Ⅱ） adsorption onto poly（aniline-co-2,4-diaminophenol） synthesized by chemically oxidative polymerization,where the Lagrangian pseudo-first-order and pseudo-second-order kinetic model,Langmuir,Freundlich isotherm models were applied to simulate the experimental parameters.The results show that mercury adsorption isotherm onto poly（aniline-co-2,4-diaminophenol） is well described by Langmuir model and the adsorption can be approximated more favorably by the pseudo-second-order model,and the Qmax is 800 mg·g-1 at pH 5.5,with ion strength 1mol·l-1 NaNO3.The calculated thermodynamic parameters（ΔG,ΔH and ΔS） show that the adsorption of Hg（Ⅱ） onto poly（aniline-co-2,4-diaminophenol） is feasible,endothermic and spontaneous.