Changes in liquid water alter nutrient bioavailability and gas diffusion in frozen antarctic soils contaminated with petroleum hydrocarbons

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Harvey, Alexis Nadine, Snape, Ian, Siciliano, Steven Douglas
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2011
• Subjects: Antarctic; Casey Station; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/etc.745; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fetc.745; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.745

Abstract Bioremediation has been used to remediate petroleum hydrocarbon (PHC)‐contaminated sites in polar regions; however, limited knowledge exists in understanding how frozen conditions influence factors that regulate microbial activity. We hypothesized that increased liquid water (θ liquid ) would affect nutrient supply rates (NSR) and gas diffusion under frozen conditions. If true, management practices that increase θ liquid should also increase bioremediation in polar soils by reducing nutrient and oxygen limitations. Influence of θ liquid on NSR was determined using diesel‐contaminated soil (0–8,000 mg kg −1 ) from Casey Station, Antarctica. The θ liquid was altered between 0.007 and 0.035 cm 3 cm −3 by packing soil cores at different bulk densities. The nutrient supply rate of NH and NO , as well as gas diffusion coefficient, D s , were measured at two temperatures, 21°C and −5°C, to correct for bulk density effects. Freezing decreased NSR of both NH and NO , with θ liquid linked to nitrate and ammonia NSR in frozen soil. Similarly for D s , decreases due to freezing were much more pronounced in soils with low θ liquid compared to soils with higher θ liquid contents. Additional studies are needed to determine the relationship between degradation rates and θ liquid under frozen conditions. Environ. Toxicol. Chem. 2012;31:395–401. © 2011 SETAC