Modification of silt microstructure by hydrocarbon contamination in freezing ground

Abstract

AbstractThe thermodynamic conditions within the active layer overlaying perennially frozen ground and in ground subjected to seasonal frost are such that there is continuing translocation of water and ice and the displacement of soil particles. The introduction of an immiscible hydrocarbon contaminant (Arctic diesel fuel) into this dynamic porous medium results in microstructural changes that take place as a function of both cryogenic processes and contaminant concentration. Micromorphological and scanning electron microscope observations combined with image analysis revealed evidence of reorganisation of silt microfabric and changes to intra-particle porosity. The degree of interaggregate porosity increased as a function of increasing concentration of the hydrocarbon contaminant. Intra-particle porosity within individual soil aggregates was observed to decrease as a function of increasing contaminant concentration.