title: Electrolysis-driven bioremediation of crude oil-contaminated marine sediments.
abstract: Bioremediation is an effective technology to tackle crude oil spill disasters, which takes advantage of the capacity of naturally occurring microorganisms to degrade petroleum hydrocarbons under a range of environmental conditions. The enzymatic process of breaking down oil is usually more rapid in the presence of oxygen. However, in contaminated sediments, oxygen levels are typically too low to sustain the rapid and complete biodegradation of buried hydrocarbons. Here, we explored the possibility to electrochemically manipulate the redox potential of a crude oil-contaminated marine sediment in order to establish, in situ, conditions that are conducive to contaminants biodegradation by autochthonous microbial communities. The proposed approach is based on the exploitation of low-voltage (2V) seawater electrolysis to drive oxygen generation (while minimizing chlorine evolution) on Dimensionally Stable Anodes (DSA) placed within the contaminated sediment. Results, based on a laboratory scale setup with chronically polluted sediments spiked with crude oil, showed an increased redox potential and a decreased pH in the vicinity of the anode of 'electrified' treatments, consistent with the occurrence of oxygen generation. Accordingly, hydrocarbons biodegradation was substantially accelerated (up to 3-times) compared to 'non-electrified' controls, while sulfate reduction was severely inhibited. Intermittent application of electrolysis proved to be an effective strategy to minimize the energy requirements of the process, without adversely affecting degradation performance. Taken as a whole, this study suggests that electrolysis-driven bioremediation could be a sustainable technology for the management of contaminated sediments.
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo (RM), Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Bellagamba
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo (RM), Italy.
authors.forename: Carolina
authors.initials: C
authors.lastname: Cruz Viggi
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo (RM), Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Ademollo
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo (RM), Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Rossetti
authors.affiliation: Water Research Institute (IRSA), National Research Council (CNR), Via Salaria km 29,300, 00015 Monterotondo (RM), Italy. Electronic address: aulenta@irsa.cnr.it.
authors.forename: Federico
authors.initials: F
authors.lastname: Aulenta
mesh_terms: D001673:Biodegradation, Environmental; D004572:Electrolysis; D059392:Petroleum Pollution; D012623:Seawater / Q000737:chemistry / Q000382:microbiology; D014873:Water Pollutants / Q000737:chemistry / Q000378:metabolism; D014876:Water Pollution
chemical_list: D014873:Water Pollutants