改性膨润土的制备及其对苯胺的吸附性能

采用十六烷基三甲基溴化铵和壳聚糖季铵盐协同对钠基膨润土进行改性,制备了一种新型的吸附剂。研究了改性膨润土吸附苯胺的机理及其主要影响因素。实验结果表明,改性膨润土对苯胺的吸附几乎不受吸附温度和溶液酸碱性影响;并在较短的时间内到达吸附平衡。外加无机盐可促进改性土对苯胺的吸附,吸附过程遵循准二阶动力学模型。改性土适合处理高浓度苯胺溶液。当苯胺质量浓度为3 000mg/L时,其吸附容量达29.7mg/g。改性土对苯胺的吸附符合Freundlich等温吸附模式,吸附机制主要是分配作用。

Preparation and Adsorption Performance toward Aniline of Modified Bentonite

A novel absorbent was prepared using Na-bentonite modified with cetyltrimethyl ammonium bromide and quaternized chitosan.The adsorption mechanism of the modified bentonite for aniline was studied,and the major factors affecting the adsorption of aniline onto the modified bentonite were investigated.The results shown the contacting temperature and pH value of the solution have no influence on the adsorption of aniline onto the modified bentonite.The adsorption equilibrium is attained in a short time.The foreign salts may improve the adsorption of aniline onto the modified bentonite.The adsorption process fits the pseudo-second-order kinetic well.The modified bentonite is suitable for the treatment of aniline solution with a high concentration.The adsorption capacity is 29.7 mg/g at pH 7.0 and 20℃ when the concentration of aniline solution is 3000 mg/L.The adsorption isotherm is accorded with the Freundlish isotherm.The main adsorption mechanism is partitioning effect.