Evaluation of adsorption of organic solvents to modified hydrophobic silica adsorbents based on Hansen solubility parameter

Abstract

• Adsorption of organic substances in aqueous solution was carried out using hydrophobic silica adsorbent. • Adsorbed amount was estimated using HSP theory. • An adsorption amount estimation formula using the difference R a of HSP values was constructed. • It was suggested that affinity is an important factor in adsorption. Adsorption is an effective methodology for the removal of organic matter. Several studies have shown that adsorption performance is dependent on pore size, specific surface area, and the affinity between the adsorbent and adsorbed material. In this study, we concentrated on the effect of the affinity between the surface of the adsorbent and the adsorbed matter by examining the adsorption of organic solvents from organic/aqueous mixtures using three types of hydrophobic silica adsorbents. The Hansen solubility parameters (HSPs) of the adsorbents were determined using the group contribution method. A linear relationship between the logarithm of the amount of adsorbed organic solvent and the difference between the HSP values of the organic solvents and adsorbents was obtained with a high correlation coefficient. These experimental results suggest that the affinity between the adsorbent and adsorbed matter can be well-described by the HSPs of the components.