Kim, J., A.H. Lee, and W. Chang.
Science of the Total Environment 612:903-913(2018)

A pilot-scale biopile field experiment for nutrient-amended petroleum-contaminated fine-grained soils was performed over the winter at a cold-climate site to determine the rate and extent of hydrocarbon biodegradation and microbial responses associated with natural seasonal freeze-thaw conditions. Treated and untreated biopiles were constructed (~3500 kg each) on an open outdoor surface at a remediation facility in Saskatoon, Canada. The treated biopile received N-P-K-based nutrient and humate amendments before seasonal freezing. Real-time field monitoring indicated significant unfrozen water content in the treated and untreated biopiles throughout the freezing period, mid November to early March. Unfrozen water was slightly more available in the treated biopile due to the aqueous nutrient supply. F3 degradation largely occurred during freezing while F2 hydrocarbons were primarily removed during thawing. Biomarker-based hydrocarbon analyses confirmed enhanced biodegradation in the treated biopile during freezing. The soil treatment increased the first-order rate constants for F2, F3, and TPH degradation by a factor of 2 to 7 compared to the untreated biopile. Shifts in bacterial community appeared in both biopiles as the pile soils froze and thawed.