壳聚糖/负载镧蒙脱土对水溶液中亚甲基蓝的吸附研究

A Research on the Adsorption of Methylene Blue in Aqueous Solution by Chitosan/La Loaded Montmorillonite

制备了壳聚糖/负载镧蒙脱土复合吸附剂,用于去除水溶液中的亚甲基蓝,对吸附过程中吸附剂用量、吸附时间的影响进行了考察。实验结果表明,当亚甲基蓝溶液的初始浓度为100 mg/L,吸附剂用量为1.5 g/L时,吸附40 min基本达到平衡,亚甲基蓝的去除率为98.50%。对吸附等温线进行线性拟合,所得数据表明,壳聚糖/负载镧蒙脱土复合吸附剂对亚甲基蓝的吸附过程符合Langmuir吸附等温模型;热力学分析表明,亚甲基蓝在壳聚糖/负载镧蒙脱土上的吸附是自发、吸热和熵增的过程。

Chitosan/Lanthanum loaded montmorillonite composite was prepared and used as an adsorbent for the removal of methylene blue in aqueous solution. The effects of adsorbent dosage and contact time on the adsorption of methylene blue were investigated. The results reveal that the equilibrium is nearly reached at 40 min and the removal percent of methylene blue attains to 98. 50 % at initial methylene blue concentration of 100 mg/L and adsorbent dosage of 1. 5 g/L. The linear fitting results of adsorption isotherm show that the adsorption isotherm model fits well with the Langmuir equation for the adsorption of methylene blue by chitosan/lanthanum loaded montmorillonite composite absorbent. By thermodynamic study,it is indicated that the nature of adsorption of methylene blue on chitosan/lanthanum loaded montmorillonite is a spontaneous,endothermic and entropy process.