CHEMICALLY TREATED ACTIVATED CARBON CLOTHS FOR REMOVAL OF VOLATILE ORGANIC CARBONS FROM GAS STREAMS - EVIDENCE FOR ENHANCED PHYSICAL ADSORPTION

The micropore surfaces of activated carbon cloths (ACCs) have been che mically modified by introducing controlled amounts of nitrogen, oxygen , or chlorine on the surface of the micropores. The treatments with am monia, oxidative reagents, or chlorine produce surfaces that are basic , acidic, and polar, respectively. The modified ACCs were evaluated fo r removal of several different volatile organic compounds (VOCs) in th e 10-1000 ppmv concentration range. VOCs examined included acetaldehyd e, acetone, and benzene. Acetaldehyde adsorption capacity increased by 500% with oxidized ACC surfaces as compared to untreated ACC surfaces . Acetone adsorption was also enhanced by 350% on oxidized surfaces. T he level of benzene uptake was high with most all of the treated surfa ces. Thermal regeneration of the ACCs at 100 degrees C was sufficient to desorb each of the three VOCs without any decrease in the adsorptio n capacity of the treated ACCs.