Competitive Adsorption of Some Hazardous Organic Pollutants from their Binary and Ternary Solutions onto Granular Activated Carbon Columns

Competitive adsorption of some priority pollutants, namely phenol, o-cresol, p-nitrophenol, m-methoxyphenol, benzoic acid and salicylic acid from their aqueous solutions onto granular activated carbon (GAC) column was studied. Experiments were carried out to determine the breakthrough curves for adsorbates when present in aqueous solutions as single-, bi- and tri-solute system to evaluate the competitive adsorption phenomenon. Results indicate that in single-solute-GAC systems, p-nitrophenol is most strongly adsorbed as compared to other phenol derivatives studied. The substituted phenols were found to adsorb to a greater extent than phenol itself. The GAC-bisolute and GAC-trisolute systems clearly show the competitive or preferential adsorption of one solute over the other, as the solutes are competing for the available GAC surface for adsorption. Initially, all the adsorbates are taken up by the GAC surface, but near the breakthrough point the more adsorbable solute is able to desorb the less adsorbable one.