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24A dynamic multi-media model that includes temperature-dependency for partitioning 25 and degradation was developed to predict the behaviour of petroleum hydrocarbons 26 during biopiling at low temperature. The activation energy (Ea) for degradation was 27 derived by fitting the Arrhenius equation to hydrocarbon concentrations from 28 temperature-controlled soil mesocosms contaminated with crude oil and diesel. The 29 model was then applied to field-scale biopiles containing soil contaminated with 30 diesel and kerosene at Casey Station, Antarctica. Temporal changes of total petroleum 31 hydrocarbons (TPH) concentrations were very well described and predictions for 32 individual hydrocarbon fractions were generally acceptable (disparity between 33 measured and predicted concentrations was less than a factor two for most fractions). 34Biodegradation was predicted to be the dominant loss mechanism for all but the 35 lightest aliphatic fractions, for which volatilisation was most important. Summertime 36 losses were significant, resulting in TPH concentrations which were about 25% of 37 initial concentrations just one year after the start of treatment. This contrasts with the 38 slow rates often reported for hydrocarbons in situ and suggests that relatively simple 39 remediation techniques can be effective even in Antarctica. 40 41

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The diffusive migration in the aqueous and vapour phases of four volatile organic compounds (VOCs: benzene, toluene, ethylbenzene and xylenes) through samples of 0.76 mm (30 mil) thick flexible poly-vinyl chloride (PVC) and 0.76 mm (30 mil) linear low-density polyethylene (LLDPE) geomembranes are compared based on both sorption and diffusion tests. Diffusion coefficients for the PVC geomembrane were in the range of 5.0–10 × 10−13 m2/s for diffusion from both the aqueous and vapour states. The range for LLDPE was 2.5–5.0 × 10−13 m2/s. Diffusive transport of VOC contaminants through geomembranes in a simulated landfill environment (i.e. in the presence of water vapour) is identical despite the phase they originated from, simplifying the analysis of contaminant transport. The partitioning (sorption) coefficients for PVC were in the range 100–1075 with respect to aqueous phase concentrations. The corresponding values with respect to vapour phase concentrations were 22–290. LLDPE partitioning (sorption) coefficients were 200–475 with respect to aqueous phase concentrations and 44–123 with respect to vapour phase concentrations.

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