Prelot Benedicte, Ayed Imen, Marchandeau Franck, Zajac Jerzy
Institut Charles Gerhardt de Montpellier, CNRS UMR 5253, Université Montpellier 2, Equipe Agrégats, Interfaces et Matériaux pour l'Energie, C.C. 1502, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France.
Environ Sci Pollut Res Int. 2014;21(15):9334-43. doi: 10.1007/s11356-014-2862-3. Epub 2014 Apr 15.
Sorption performance of cation-exchange resins Amberlite® IRN77 and Amberlite™ IRN9652 toward Cs(I) and Sr(II) has been tested in single-component aqueous solutions and simulated waste effluents containing other monovalent (Effluent 1) or divalent (Effluent 2) metal cations, as well as nitrate, borate, or carbonate anions. The individual sorption isotherms of each main component were measured by the solution depletion method. The differential molar enthalpy changes accompanying the ion-exchange between Cs+ or Sr2+ ions and protons at the resin surface from single-component nitrate solutions were measured by isothermal titration calorimetry and they showed a higher specificity of the two resins toward cesium. Compared to the retention limits of both resins under such idealized conditions, an important depression in the maximum adsorption capacity toward each main component was observed in multication systems. The overall effect of ion exchange process appeared to be an unpredictable outcome of the individual sorption capacities of the two resins toward various cations as a function of the cation charge, size, and concentration. The cesium retention capacity of the resins was diminished to about 25% of the "ideal" value in Effluent 1 and 50% in Effluent 2; a further decrease to about 15% was observed upon concomitant strontium addition. The uptake of strontium by the resins was found to be less sensitive to the addition of other metal components: the greatest decrease in the amount adsorbed was 60% of the ideal value in the two effluents for Amberlite® IRN77 and 75% for Amberlite™ IRN9652. It was therefore demonstrated that any performance tests carried out under idealized conditions should be exploited with much caution to predict the real performance of cation exchange resins under conditions of cation competition.
已在单组分水溶液以及含有其他一价（废水1）或二价（废水2）金属阳离子、硝酸根、硼酸根或碳酸根阴离子的模拟废水流出物中，测试了阳离子交换树脂Amberlite® IRN77和Amberlite™ IRN9652对Cs(I)和Sr(II)的吸附性能。通过溶液耗尽法测量了各主要成分的单独吸附等温线。通过等温滴定量热法测量了单组分硝酸盐溶液中Cs⁺或Sr²⁺离子与树脂表面质子之间离子交换伴随的微分摩尔焓变，结果表明这两种树脂对铯具有更高的选择性。与两种树脂在这种理想化条件下的保留极限相比，在多阳离子体系中观察到对各主要成分的最大吸附容量有显著降低。离子交换过程的总体效果似乎是两种树脂对各种阳离子的单独吸附容量作为阳离子电荷、大小和浓度的函数的不可预测结果。在废水1中，树脂的铯保留容量降至“理想”值的约25%，在废水2中降至50%；在同时添加锶后，进一步降至约15%。发现树脂对锶的吸收对添加其他金属成分不太敏感：对于Amberlite® IRN77，两种废水中吸附量的最大降幅为理想值的60%，对于Amberlite™ IRN9652为75%。因此证明，在理想化条件下进行的任何性能测试在预测阳离子交换树脂在阳离子竞争条件下的实际性能时都应非常谨慎地使用。
