A distributed reactivity model for sorption by soils and sediments. 6. Mechanistic implications of desorption under supercritical fluid conditions

摘要: Phenanthrene desorption isotherms for five dry soil materials were measured in supercritical carbon dioxide (SC CO2) at up to 12 different temperature (40−60 °C) and pressure (120−310 atm) conditions each soil. The Freundlich model adequately described all 40 obtained. At condition, sorption capacity increased with increasing organic matter content a positive dependence on oxygen content. Trends SC CO2 qualitatively consistent variations phenanthrene solubility. A diagenetically altered shale material displayed increases similar magnitude solubility changes, but stimulated from surface soils far less than expected considerations. Swelling of amorphous macromolecular (SOM) the non-shale higher pressures is postulated increase SOM phase, largely offsetting solven...