Simulation of the adsorption capacity of polar organic compounds and dyes from water onto activated carbons: Model development and validation

Abstract

A model approach is developed to simulate the adsorption isotherms of low-molecular-weight polar organic compounds (LMWPOCs), halogenated LMWPOCs, and dye molecules onto activated carbons (AC). The models were based on the Dubinin–Astakhov equation, with the limiting pore volume of adsorbent estimated from the pore size distribution data, and the adsorption affinity of the adsorbate described by the molecular connectivity index. The models were used to simulate the adsorption data of 87 LMWPOCs onto six ACs, 25 halogenated LMWPOCs onto two ACs and 22 dyes onto three ACs. The developed models follow the experimental data fairly well, with errors of 49, 33 and 43% for the tested LMWPOCs, halogenated LMWPOCs, and dyes, respectively. This study shows that the developed model approach may provide a simple means for the estimation of adsorption capacity for LMWPOCs and dyes onto ACs in water.

Keywords

• Adsorption isotherm
• Polanyi-Dubinin model
• MCIs
• Micropore volume
• Organic compounds