由吸附等温线分析膨润土的分形孔隙

Fractal Analysis of Bentonite Porosity by Using Nitrogen Adsorption Isotherms

膨润土是一种多孔的粘土材料,对气相和液相中的污染物均有很好的净化效果。为了了解其对气体的吸附性能,用氮气吸附等温线分析了2种膨润土和1种活性白土的BET比表面积和孔隙分布,并应用基于FHH模型的方法计算了它们的分形维数。结果表明,普通膨润土的分形维数接近2,而活性白土的达到了2.59。讨论了孔隙度、比表面积以及分形维数等参数与吸附量的关系,表明分形维数更能反映膨润土对气体的吸附性能。

The bentonite is a porous clay material, and can adsorb varied pollutant in gas phase and liquid phase. In order to understand the performance of bentonites on the gas adsorption, the surface area and pore distribution of two bentonites and one activated bentonite was studied by using their nitrogen adsorption isotherms. Their fractal dimensions was also calculated by a method based on FHH (Frenkel-Halsey-Hill) model. The results indicate that the fractal dimensions of the common bentonites are slightly more than 2, however, the acid activated bentonite is 2.59. It is much more revealed by fractal dimensions in characterization of the adsorbility of bentonite compared with porosity and surface area.