N235萃淋树脂吸附盐酸的热力学和动力学

摘要

Thermodynamics and kinetics of adsorption HCl using N235 levextrel resin were researched by static adsorptive method.The law of adsorption was discussed.The results show that the adsorption of N235 levextrel resin for HCl are in accordance with Langmuir and Freundlich isothermal adsorption equation but the former is better.The maximum adsorption amount of the levextrel resin for HCl is 0.367 2 mmol/g at the conditions of 323 K and HCl concentrate of 74.13 mmol/L.The thermodynamics parameters calculating are that ΔH=18.066 kJ/mol,ΔS=65.1 J/(mol·K),ΔG303K=-1.659 kJ/mol,ΔG308K=-1.985 kJ/mol,ΔG313K=-2.31 kJ/mol,ΔG318K=-2.636 kJ/mol based on the previous experiment data.It shows that the adsorption process of N235 levextrel resin for HCl is a endothermic(ΔH>0),increasing entropy(ΔS>0)and spontaneous physical adsorption(ΔG∈- 20~0 kJ/mol) process.Adsorption kinetics results show that the adsorption process corresponds to quasi two stage kinetic equation(R2>0.99) and is controlled by film diffusion.%采用静态吸附法研究了N235萃淋树脂吸附HCl的热力学、动力学,探讨了吸附规律.结果表明:N235萃淋树脂对HCl的吸附同时遵循朗缪尔(Langmuir)和弗兰德里希(Freundlich)吸附等温模型,但前者契合程度更好;在温度323 K、HCl浓度74.13 mmol/L条件下,N235萃淋树脂对HCl的最大吸附量为0.367 2 mmol/g;热力学计算结果表明,ΔH=18.066 kJ/mol,ΔS=65.1 J/(mol·K),ΔG303K=-1.659 kJ/mol,ΔG308K=-1.985 kJ/mol,ΔG313K=-2.31 kJ/mol,ΔG318K=-2.636 kJ/mol,可以认为,吸附过程是吸热(ΔH>0)、熵增(ΔS>0)、可自发进行的物理吸附(ΔG∈-20~0 kJ/mol);吸附动力学研究表明,吸附过程与准二级动力学方程契合得更好(相关系数R2>0.99),吸附速率受液膜扩散控制.