In Situ Chemical Oxidation Coupled to Biodegradation Raw sequence reads

Field and batch experiments were conducted to assess whether a modified approach for in situ chemical oxidation (ISCO) (with MgO2 and Fe2O3 particles recovered from acid mine drainage treatment) can enhance LNAPL (light non-aqueous phase liquid) dissolution and produce bioavailable soluble compounds. This modified ISCO approach was coupled to biodegradation to further remove residual compounds by microbial-mediated processes. Pure palm biodiesel (B100) was chosen to represent a poorly water-soluble compound that behaves as LNAPLs and 100 L were released to a 2 m2 area excavated down to the water table. A past adjacent B100-field experiment under natural attenuation was conducted as a baseline control. Results demonstrated the enhancement of organic compound dissolution and production of soluble compounds due to the modified in situ chemical oxidation. The slow release of H2O2 by MgO2 decomposition (referred as partial chemical oxidation) and production of soluble compounds allowed the stimulation of microbial growth and promoted a beneficial response in microbial communities involved in oxidized biodiesel compound biodegradation. This is the first field experiment to demonstrate that this modified ISCO approach coupled to biodegradation could be a feasible strategy for the removal of poorly water-soluble compounds (e.g. biodiesel) and avoid the long-term effects generally posed in source-zones.