Bioelectrochemical remediation of oil-contaminated marine sediment via novel microbial electrochemical snorkel

Abstract

Following an unintentional oil spill, marine sediments serve as an ultimate sink for a variety of human-made organic pollutants, especially petroleum hydrocarbons. The activity of indigenous microfloral populations connected to biogeochemical cycles, in which sulfur is transported to and from its oxidized and reduced species, is crucial to the degradation of these compounds. This study presents an additively manufactured electrode made of super nickel alloy Inconel 718 ("the electrochemical snorkel") inserted into oil- contaminated sediment originating from the Baltic Sea in the north of Finland, consequently establishing an electrochemical contact between the anaerobic polluted marine sediment and the aerobic superjacent water, has a significant influence on the microbial activity in the core of the sediment. The electrochemical snorkel enhanced organic pollutant oxidation-driven sulfate reduction activities. Two types of chemical analyses have been implemented to investigate this phenomenon, proposing that the snorkel enhanced the reduction of the sulfate anions in all samples and that the electrode surface patterning has given better hydrocarbons degradation potential to the electrode possessing a microstructure. Overall, the findings of this study can be considered as a step along the way of providing industrially scalable materials to manufacture the microbial electrochemical snorkel which would positively impact benignly counteracting oil spills in water bodies.