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Iron coated granular activated carbon (Fe-GAC) has been proven to be effective for removing selenite from aqueous solution in batch studies. Design and use of the adsorbent in column settings require understanding the key mass transfer characteristics, which are required for full-scale applications. In this study, rapid small-scale column tests (RSSCTs) were conducted at various empty bed contact times (EBCTs). Pore and surface diffusion model (PSDM) was introduced to predict selenite breakthrough curves of continuous flow packed columns containing iron coated granulated activated carbon. Effluent Se(IV) breakthrough was incipient immediately in the experiment with 0.055-min EBCT, whereas about 780 bed volumes of water at 1.0 mg/L initial concentration of Se(IV) was treated at an EBCT of 0.447 min before breakthrough occurred. The adsorption capacity was estimated using the Freundlich isotherm model. The adsorption results of the selenite on Fe-GAC columns demonstrated that the PSDM can predict the column performance satisfactorily. Full scale column design criteria, such as hydraulic loading rate (HLR), carbon usage rate (CUR), and degree of column utilization (DoCU) were calculated and recommended. .

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