氨基萘酚磺酸在改性超高交联吸附树脂和弱碱树脂上的静态吸附行为比较

优选弱碱树脂ND 90 0和改性超高交联吸附树脂AL 8,比较研究两者吸附 1 氨基 2 萘酚 4 磺酸 (1,2 ,4 酸 )的静态吸附行为和吸附热力学特征 .两种树脂对 1,2 ,4 酸的吸附属于优惠的吸热吸附过程 .Langmuir和Freundlich两种等温方程都能够很好地描述ND 90 0对 1,2 ,4 酸的吸附等温线 ;仅Freundlich等温方程能很好地拟合AL 8的静态平衡吸附结果 .两种树脂对 1,2 ,4 酸的吸附自由能变均为负值 ,表明了吸附的自发性 ;吸附熵变均为正值 ,与“溶剂置换”现象有关 ;吸附焓变均为正值 ,主要是由于部分化学吸附的存在 .而ND 90 0的吸附焓变远远大于AL 8,表明前者以化学吸附为主、而后者以物理吸附为主的吸附机理 .

COMPARISON STUDIES ON THE STATIC ADSORPTION PERFORMANCE OF AMINO-NAPHTHOL-SULFONIC ACID ONTO WEAKLY BASIC RESIN AND MODIFIED HYPERCROSSLINKED POLYMERIC ADSORBENT

Weakly basic resin ND-900 and modified hypercrosslinked polymeric adsorbent AL-8 were selected to remove 1-amino-2-naphthol-4-sulfonic acid (1,2,4-acid) from aqueous media,and the comparison study on the static adsorption performance and thermodynamics was developed.Both of the tested adsorbents exhibited an endothermic and favorable adsorption process.The Langmuir and Freundlich equations both can give well fits to the adsorption data of 1,2,4-acid on ND-900,while only the latter can be used for AL-8.The negative value of ΔG indicates the spontaneous nature of the adsorption process,and the positive value of ΔS shows the closely relationship to the phenomena of “solvent exchange",and the positive value of ΔH proves the presence of chemical adsorption.The much larger values of ΔH for ND-900 than those for AL-8 inform the predominant adsorption mechanism:a chemical adsorption for ND-900,whereas a physical one for AL-8.