EXPERIMENTAL AND MODELED RESULTS DESCRIBING THE ADSORPTION OF ACETONEAND BENZENE ONTO ACTIVATED CARBON-FIBERS

Activated carbon fibers (ACF) were used to adsorb ppmv concentrations of volatile organic compounds (VOCs) from laboratory generated gas str eams. VOCs considered were benzene and acetone because the VOC are com monly found in indoor air and have potential to increase health risks to humans. ACF were used as the adsorbent because they typically exhib it higher adsorption capacities and faster adsorption kinetics than co mmercially available granular activated carbons (GAC) and show potenti al as an adsorbent to effectively remove VOCs from indoor air. Adsorpt ion models by Dubinin and coworkers (Dubinin, 1975), based on the theo ry of volume filling of micropores, and an empirical model by Freundli ch were used to fit the measured adsorption isotherms. Agreement betwe en the modeled and experimental results for acetone and benzene using the Dubinin-Radushkevich equation generally improved with increasing B ET surface area and produced reasonable fits of the adsorption isother ms for both acetone and benzene. The Freundlich equation produced valu es for correlation coefficients (R) between modeled and experimental d ata from 0.980 to 0.997, indicating the validity of using the Freundli ch equation to model the adsorption isotherms over the concentration r ange of interest. These results indicate that ACF show potential as an adsorbent for removing low concentrations of VOCs from indoor air.