| A modified landfarm was constructed in Calgary, Alberta using two batches of moderately contaminated (<4000 mg/kg) clay loam subsoil. One batch was contaminated with crude oil, the other with a mixture of crude oil and flare pit waste. Various treatment regimes were applied to each contaminated soil over 233 days. Treatments included: mechanical aeration, compost amendment, nutrient amendment and moisture addition.; Total extractable hydrocarbon concentrations were monitored from January 5 to August 26, 2002 using gravimetric analysis and gas chromatography. Changes in soil microbial community structure were also monitored over this period using MPN enumeration and FAME analysis.; Results show that landfarming can stimulate the hydrocarbon-degrading biomass to remove a substantial concentration (>43%) of crude-oil contamination from soils during low temperature periods (January to May). Results also demonstrate that the presence of flare pit waste in the contaminated soil will substantially decrease the effectiveness of bioremediation treatments. |
