Activated carbon adsorption is a powerful technology for removing organic contaminants from water. Information about adsorption isotherms is important to assess the adsorbability of organic contaminants and to select effective activated carbons for water treatment applications. Many activated carbons with different physical and chemical characteristics are manufactured, and only few isotherm data are available for the more than 100,000 chemical substances and mixtures that have been or are currently being produced. The goal of this research was to develop a model that permits the prediction of adsorption isotherms from adsorbent and adsorbate properties. The Polanyi-Dubinin-Manes (PDM) theory served as the basis for model development. To apply the PDM theory to aqueous contaminants, the affinity of water and of the contaminant for the activated carbon surface needs to be known. The affinity coefficient for water was estimated from the adsorbent oxygen content. Affinity coefficients of individual adsorbates were estimated from adsorption isotherm data collected by the U.S. EPA for 62 neutral organic contaminants. These affinity coefficients were used to develop a poly-parameter quantitative structure-property relationship (QSPR) that permits the estimation of a contaminant’s affinity coefficient from molecular descriptors. To illustrate the applicability of the developed model, single-solute adsorption isotherms were predicted for representative contaminants on several activated carbons.

Predicting adsorption isotherms from adsorbent and adsorbate properties

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.