COMPETITIVE ADSORPTION PHENOMENA OF PETROCHEMICALS - BENZENE, TOLUENE, AND XYLENE IN HEXANE IN FIXED-BEDS OF SANDS

Present-day massive exploration, extraction, transport, and use of pet rochemicals pose a real threat of continuous or occasional accidental contamination of precious groundwater. However, the knowledge of the p athways and mechanisms involved in the transport, retention, and degra dation of such chemicals once they are within the soil matrix is very limited. One of the important means of petrochemical retention in the soil is through the process of chemical adsorption onto the soil. An i nvestigation was conducted to observe the adsorption phenomena of seve ral components of petrochemicals (benzene, toluene, and xylene) solved in hexane utilizing the columnar continuous plug-flow configuration o f a fixed bed of sands. Three types of soils were investigated for the time variation of the adsorption of the organic chemicals. The result s are the indicative values of the adsoption of the principal componen ts of petrochemicals in paacked-soil-bed subjected to tortuous seepage flow conditions of the fluids. The adsorption results are presented i n the form of breakthrough curves. The paper includes the analytical m ethodology of UV spectroscopy which was utilized to measure the concen trations of various chemical components of the petrochemical mixture.