【摘要】 选用阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)改性膨润土以提高膨润土对ClO4-的吸附能力.试验结果表明,CTAC改性能显著提高膨润土对ClO4-的吸附能力,在0.1～1mmol·L-1的ClO4-溶液中,6h内能迅速达到吸附平衡.有机膨润土对ClO4-的吸附最符合Langmuir等温吸附模型,其吸附容量可达0.48mmol·g-1.pH值在4～10范围内变化对ClO4-的吸附几乎没有影响.高的分配系数(Kd>1.5×103cm·3g-1)表明有机膨润土对ClO4-有很高的选择性,各阴离子的分配系数从小到大的顺序为HPO24-<SO42-<NO3-<ClO4-,这与阴离子的自由水合能大小相一致.1mol·L-1HCl溶液对吸附剂的再生效率在96%左右,可直接使用,不用再改性.更多还原

【Abstract】 Cationic surfactant cetyltrimethylammonium chloride (CTAC) was employed to modify a bentonite for enhancing its adsorption for perchlorate. The results showed that CTAC modification greatly improved adsorption of bentonite. The perchlorate uptake on CTAC-bentonite from 0.1 to 1 mmol·L-1 solution rapidly attained equilibrium within 6 h. The perchlorate uptake on CTAC-bentonite followed the Langmuir isotherm model with capacity of 0.48 mmol·g-1. In addition, the adsorption capacity persisted in a wide pH of 4~10. High selectivity of CTAC-bentonite for perchlorate ion was reflected in the high distribution coefficient values (>1.5×103 cm3 · g-1) with selectivity sequence of HPO2-4 < SO2-4 < NO-3< ClO-4. This selectivity sequence corresponded to the sequence of increasing hydration energy of anions. CTAC-bentonite regeneration using 1 mol·L-1 of HCl solution was investigated, which showed efficiency of 96%. CTAC-bentonite could be reused directly after regeneration with 1 mol·L-1 of HCl solution.更多还原