A field trial of in situ chemical oxidation to remediate long-term diesel contaminated Antarctic soil

In situ chemical oxidation (ICO) has been identified as a potential technology for the remediation of petroleum hydrocarbon contaminated sites in Antarctica. ICO involves introducing reactive chemicals to contaminated soils so that organics such as petroleum hydrocarbons are oxidised to environmentally innocuous compounds. This paper details two field trials that were undertaken to evaluate the feasibility of using a surface application of these oxidative treatments (Fentonʹs reagent, hydrogen peroxide and sodium hypochlorite) to remediate petroleum contaminated soil at Old Casey Station, East Antarctica. Results show that the ICO technology used at this site, where contamination occurred over a decade ago, did not significantly reduce petroleum hydrocarbon concentrations and would likely hinder biodegradation through the destruction of subsurface microbial communities. Further treatment testing and optimisation is required before ICO would be an effective remediation strategy for petroleum contaminated sites in Antarctica. However, the near complete destruction of subsurface microbiota, coupled with a discoloured orange soil residue and soil heating, mean that other more environmentally sensitive techniques such as bioremediation are our preferred treatment methodology.