A simplified method for determination of the break-through time of an adsorbent layer

Adsorption on a fixed bed of granulated adsorbent is an important method for water and wastewater treatment. Applied as one of the final stages in the treatment it reduces significantly the concentration of many pollutants. In view of such an application, a simplified method for determination of the break-through time of an adsorbent layer has been proposed. This time defines a protective action of a fixed bed before a pollutant of a concentration higher than 5% of the initial value appears in the effluent. The method is based on the assumption of an external diffusional model of adsorption kinetics and a model of zone migration and classification of adsorbates in the liquid phase and in the adsorbing phase during adsorption from a binary solution. The method was verified experimentally in the system of GAC—aqueous one-component and binary solution of phenol, p-nitrophenol, benzoic acid and chlorophenols. For longer beds the prediction error of the break-through time did not exceed 10%. The method enables a significant reduction or even elimination of troublesome experimental investigations of kinetic and dynamic aspects of fixed bed adsorption.