基于RCOO^(-+)N(CH_3)_3R'型两性树脂法的MDEA溶液离子净化研究

Study on ion purification of MDEA solution based on RCOO^(-+)N(CH_3)_3R' amphoteric resin method

以RCOO^(-+)N(CH_3)_3R'为功能基团制备了一种两性交换树脂,对其孔结构、交换容量以及红外进行表征测试,通过阴阳离子的静态吸附实验,研究其对MDEA溶液中Fe^(3+)和C_2O_4^(2-)的等温吸附性能、吸附热力学以及动力学特性。结果表明,该树脂中两性基团含量基本相等,以介孔结构为主;等温吸附行为符合Langmuir模型,以内盐键为主要吸附位点等当量的吸附阴阳离子,对高价离子和有机酸根离子具有更高的吸附选择性;Fe^(3+)和C_2O_4^(2-)在两性树脂上的吸附符合以外扩散为控制步骤的Lagergren拟二级吸附模型,是混乱度减小的自发放热过程。

An amphoteric exchange resin was prepared by using RCOO^-+N(CH 3)3R'as a functional group.The pore structure,exchange capacity and infrared were characterized.The static adsorption experiments of anions and cations were used to study Fe3+in MDEA solution.Isothermal adsorption performance,adsorption thermodynamics and kinetics of C 2O2-4.The results show that the content of amphiphilic groups in the resin is basically equal,mainly mesoporous structure;the isotherm adsorption behavior is consistent with the Langmuir model,and the internal salt bond is the equivalent adsorption site for the adsorption sites,and the high-valent ions and organic acid ions have higher adsorption selectivity;the adsorption of Fe3+and C 2O2-4 on the amphoteric resin conforms to the Lagergren pseudo-secondary adsorption model with the outer diffusion as the control step,which is the self-heating process with reduced chaos.