Prediction of the phenol removal capacity from water by adsorption on activated carbon

Abstract

Despite the improvement in understanding the structure of the activated carbons, the procedure for developing new carbonaceous materials suitable for the removal of phenolic compounds is still largely based on trial and error. Until now, there have been no predictive models to assist in the selection or synthesis of these adsorbents. Here, we apply molecular simulation to better understand the pore size–adsorption relationship in activated carbons. We simulated a set of phenol isotherms for different carbon pore sizes (8.9, 18.5, and 27.9 Å), named representative pores. The pore size of 8.9 Å is the most efficient in removing diluted phenol in water and was most effective at concentrations of 1.6 × 10−5 mol/L. The other pores are effective at concentrations of three orders of magnitude above this. A predictive approach for phenol removal capacity, based in the representative pore methodology, was proposed and validated for commercial activated carbon. Moreover, we present evidence that this method can be extended to other phenolic compounds. HIGHLIGHTS Molecular simulation helps to investigate the pore size–adsorption behavior of phenol-diluted solutions in activated carbon.; Representative pores can predict adsorption in commercial activated carbon.; The method can be extended for others phenolic compounds.;

Keywords

• activated carbon
• adsorption
• molecular simulation
• phenol