Montmorillonite (Mt) is a potential adsorbent for volatile organic vapor removal from contaminated soils because of its rich reserves and porous nature, but its inertia surface property has limited its application for polar compounds. In this study, modifications of Mt were carried out by high energy ball milling with H2O2 and tetramethylammonium bromide (TMAB) to obtain adsorbents with both high porosity and abundant Si-OH groups (BHTMt). The microporous structure produced by TMAB insertion as well as the silanol (Si-OH) groups formed by H2O2 oxidation improved the adsorption of acetone by the modified material. The adsorption capacity of BHTMt for acetone was increased by 80% compared to the original Mt. The effect of H2O2 dosage on the adsorption performance for gaseous acetone was investigated by dynamic adsorption experiments. The adsorption kinetic results demonstrated that the adsorption of acetone by the modified material was subject to both physical and chemical adsorption. Density functional theory calculations indicated that there was no obvious interaction between TMAB and acetone, and the materials adsorbed acetone mainly through hydrogen bonding interaction of Si-OH as well as pore filling effects.
Keywords: Acetone; High energy ball milling; Hydrogen peroxide; Montmorillonite; Tetramethylammonium bromide.
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