RETENTION AND VOLATILIZATION OF KEROSENE - LABORATORY EXPERIMENTS ON GLACIAL AND POSTGLACIAL SOILS

The influence of environmental conditions and soil characteristics on the retention and volatilisation of kerosene hydrocarbons in soils is investigated through laboratory experiments in six different glacial a nd post-glacial soils. The soils ranged between 0.55 and 1.80 g cm-3 i n density, 29% and 70% in porosity, 0.4% and 28% in organic matter con tent, and 0% and 51% in clay content. The water retention capacity (WR C) could be estimated on basis of the bulk density and the sand, silt, clay and organic matter contents for many of the soils; for these soi ls a simple linear relation was identified between WRC and the kerosen e retention capacity (KRC). Furthermore, the combined effects of soil porosity and soil moisture content on the KRC were found to be signifi cant and could be quantified by a linear relationship. For moisture co ntents that can be expected in humid climate zones, the KRC will be re latively low and exhibit small variations between different soils. The effect of temperature on KRC was found to be small. The kerosene vola tilisation flux was quantified as a function of time by a power law re lationship, based on the initial surface density of kerosene in the so il and the prevailing temperature. The C9-C11 components of the kerose ne had selectivities above zero and were thus removed preferentially, while the C14 and C15 components were characterised by negative the so il by increasing the concentration of the C14 and C15 components. The results for the different soil types indicate that the organic matter content of the soil affects the selective volatilisation, possibly thr ough hydrophobic adsorption on surfaces, whereas the clay content appe ars to be less influential.