Keywords: electrokinetics, electrophoretic mobility, surface potentials, reduced potentials, adsorption equilibrium, aqueous solutions, weak organic electrolytes, mass titration, activated carbon surfaces, aqueous adsorption
Analysis of adsorption equilibrium for aqueous solution of weak organic electrolyte-activated carbon system
Several models for the adsorption of weak organic electrolytes on activated carbons from dilute aqueous solutions have been reported recently. It is apparent, however, that the electrokinetics of carbon surface has not been sufficiently addressed by these studies. The present treatment therefore employed the fundamental concepts provided by these studies, in conjunction with electrokinetic measurements and mass titration, to predict experimentally observed adsorption data. Important and convenient parameters for characterisation of activated carbon surfaces were thus evaluated. The interplay between reduced potential, pH and adsorption capacity were examined for adsorption of weak acidic electrolytes on untreated, oxidised and nitrided activated carbons. The best-fit parameters for aqueous adsorption on the carbon samples were also acquired.