Effect of Bentonite Modification with Glycerol on Adsorbent Structure and Physicochemical Characteristics

Abstract

The effect of targeted, glycerol-aided modification of natural clay mineral bentonite was studied in terms of changes in the structure and general properties of the adsorbent material. The modification was performed using natural bentonite with a high content of montmorillonite. The bentonite micro- and mesoporosity can be increased by introducing certain struts—pillars into the interlayer structure of aluminosilicates. The data on structural features and physicochemical properties of granular formed samples of adsorbents based on the original bentonite clay were compared to those of glycerol-modified ones. Specific surface area, porosity, volume, and pore size distribution values of the samples studied were measured using the sorption method and gas capillary condensation techniques. The structure of the samples was determined was determined with X-ray phase analysis, and their elemental composition was found with an energy dispersive spectrometer. It was proved that bentonite was modified by pyrolytic carbon resulting from decomposition of glycerol in an oxygen-free medium, in the course of annealing of pellets. The modified bentonite adsorbent had a 4-fold higher specific surface area value compared to the starting material with retention of the basic elemental composition.