黄原酸化交联壳聚糖树脂对Ag(Ⅰ)的吸附

Adsorption of Ag (Ⅰ) on xanthated cross-linked chitosan resin

采用微波辐射下制备的黄原酸化交联壳聚糖树脂(XCCTS)来吸附水溶液中的Ag(Ⅰ),研究了pH值和温度对XCCTS吸附性能的影响,并用FT-IR和XRD对XCCTS吸附Ag(Ⅰ)前后的结构进行了表征.结果表明,XCCTS可有效吸附水中的银离子,pH值和温度对XCCTS吸附Ag(Ⅰ)有显著影响,在pH=4.0和50℃时XCCTS可获得最大吸附量.采用Lagergren一级和拟二级动力学模型对XCCTS吸附Ag(Ⅰ)的动力学数据进行了分析.吸附过程更符合拟二级动力学模型.分别用Langmuir和Freundlich等温线模型对吸附平衡数据进行了处理,并计算了Ag(Ⅰ)吸附过程的热力学参数.实验数据既符合Langmuir等温方程又符合Freundlich等温方程,但用Langmuir方程拟合的相关系数相对更大.吸附过程是自发的吸热过程.

Xanthated cross-linked chitosan resin(XCCTS) under microwave irradiation was used for adsorbing Ag(Ⅰ) ions from aqueous solution.The influence of pH and temperature on the adsorption capacity of XCCTS was investigated.The structure and crystalline of XCCTS before and after adsorption of Ag(Ⅰ) were characterized by FT-IR and XRD.The studies showed that XCCTS could effectively adsorb Ag(Ⅰ) ions from aqueous solution.The adsorption of Ag(Ⅰ) on XCCTS was strongly affected by pH and temperature.The maximum adsorption capacity was observed at pH = 4.0 and 50 ℃.The kinetic data were tested by using Lagergren-first-order and pseudo second-order kinetic models.The adsorption process was found to obey the pseudo-second order kinetic model.Thermodynamic parameters of the Ag(Ⅰ) adsorption process were calculated.The experimental data fitted Langmuir and Freundlich adsorption equations,but the Langmuir fitting coefficient was larger.The adsorption process was spontaneous and endothermic.