CONCEPTUAL-MODEL FOR THE ADSORPTION OF ORGANIC-COMPOUNDS FROM THE GAS-PHASE TO LIQUID AND SOLID-SURFACES

Adsorption of organic pollutants from the gas phase to ambient surface s has a great impact on the environmental mobility of these compounds. In a recent paper, gas phase adsorption coefficients for different co mpounds and surfaces have successfully been predicted based on thermod ynamic parameters (surface free energies) without the use of any empir ical fitting. However, the surface free energies required for these ca lculations are only known for a limited number of adsorbates and surfa ces, these parameters can be substituted by others (in p(L)(o), beta, and alpha) that are tabulated for a wide range of compounds. Validatio n of this extended model with experimental data shows good results. At the same time, the conceptual understanding of the adsorption equilib rium in terms of van der Waals and Lewis acid-base (electron donor-acc eptor) interactions, which is provided by the original model, remains unaltered. This paper is concluded by a discussion of our current know ledge of the surface parameters that are additionally required for the calculations.