Abiotic and biotic transformation of petroleum hydrocarbons coupled with redox cycling of structural iron in clay mineral

The objective was to assess the effect of abiotic pre-oxidation of petroleum hydrocarbons on subsequent biodegradation when coupled with Fe(III) reduction under anaerobic condition. In the abiotic phase, hydrocarbon transformation, production of oxygen-containing compounds, and mineral transformation were monitored. In the subsequent biotic phase under anaerobic condition, Fe(III) reduction and hydrocarbon degradation were studied. We provided evidence that (1) production of oxygen-containing organic compounds upon abiotic oxidation diversified anaerobic activation pathways of the compounds and (2) specific thermophilic anaerobes were enriched and responsible for the couped Fe(III) bio-reduction and hydrocarbon biodegradation.