ADSORPTION-ISOTHERMS OF VOLATILE ORGANOCHLORINE POLLUTANTS ON GEOMATERIALS

Adsorption isotherms of volatile organochlorine pollutants on geomater ials. Leaching of industrial waste storage settings can lead to severe water resource pollution. Geomaterials barriers made from cement, ben tonite and active carbon can overcome such problem. Retention properti es of such barriers towards some volatile organochlorine compounds (di chloromethane, 1,2-dichloroethane, chloroform, trichloroethylene, 1,1, 2,2-tetrachloroethane, chlorobenzene) have been assessed through the d etermination of adsorption isotherms using purge and trap techniques c oupled with gas chromatography and flame ionisation detection. It has been shown that, according to the VOC, retention is mainly due to acti ve carbon alone or, fora part, to the inorganic components of the geom aterials. Retention can be predicted from considerations founded on ch emical formula, partition coefficient in the water-n-octanol system (w hich can be computed from Rekker hydrophobic partial constants) and ad sorption energy on silica and alumina.