A correction factor for predicting the multicomponent adsorption of air stripper offgas

Abstract

Air stripping is a common way to remove volatile organic compounds (VOCs) from drinking water with the off-gas from air stripping often requiring treatment. The removal of the VOCs from the off-gas can be achieved by adsorbing the VOCs onto granulated activated carbon (GAC). When the capacity for GAC to adsorb VOCs becomes exhausted, VOCs are again released to the atmosphere. A previous model of the GAC adsorption process used molar volume, V M , as an affinity coefficient to predict the breakthrough curves of the VOCs; however, an additional correction factor, δ, which had no theoretical base was necessary to adequately fit multicomponent breakthrough curves. In this paper, Hilderbrand's cohesive energy density term, c, is applied as the correction factor providing a more theoretical basis for multicomponent adsorption. When c is applied to the V M affinity coefficient, the heat of vaporization (H v ) adequately describes the multicomponent data and does not require additional correction factors to fit the breakthrough curves of a mixture of seven different chlorinated VOCs.