膨润土对Pb^(2+)的吸附及铝的影响研究

Study on Adsorption of Pb^(2+) on Bentonite and Effects of Aluminum Ions

研究膨润土对水溶液中铅的吸附特性以及铝对铅吸附的影响。通过各组吸附实验,建立膨润土对水溶液中铅离子的吸附最佳条件,天然膨润土对铅的吸附平衡时间约为60 min,其吸附符合一级动力学方程;铅吸附最适p H=9;天然膨润土对水溶液中铅离子的吸附规律符合Freundlich等温方程和Langmuir等温方程,呈显著相关性;加入少量铝离子时,吸附除铅能力增强,但继续增加铝浓度,去除能力降低,该现象主要通过铝盐水解所致的p H变化起调节作用,电中和作用不明显。

The adsorption characteristics of lead on natural bentonite and effect of aluminum ions were studied. The results show that the adsorption completes in 60 min, conforms to first-order reaction, optimum pH is 9;the adsorption of lead ions on bentonite conforms to both Langmuir isotherm equation and Freundlich isotherm equation with significant correlation. When adding a small amount of aluminum ions in the reaction system, the ability of lead removing enhances, and then decreases with further increase of aluminum ion content, which is resulted from the adjusting of pH, but is not caused by the charge neutralization.