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The "Oil-Spill Snorkel": an innovative bioelectrochemical approach to accelerate hydrocarbons biodegradation in marine sediments.

Cruz Viggi C, Presta E, Bellagamba M, Kaciulis S, Balijepalli SK, Zanaroli G, Petrangeli Papini M, Rossetti S, Aulenta F - Front Microbiol (2015)

Bottom Line: Electrons flow through the snorkel up to the part exposed to the aerobic environment (the cathode), where they reduce oxygen to form water.Here we report the results of lab-scale microcosms setup with marine sediments and spiked with crude oil.Collectively, the results of this study confirmed that the snorkels accelerate oxidative reactions taking place within the sediment, as documented by a significant 1.7-fold increase (p = 0.023, two-tailed t-test) in the cumulative oxygen uptake and 1.4-fold increase (p = 0.040) in the cumulative CO2 evolution in the microcosms containing three snorkels compared to snorkel-free controls.

View Article: PubMed Central - PubMed

Affiliation: Water Research Institute, National Research Council Rome, Italy.

ABSTRACT
This study presents the proof-of-concept of the "Oil-Spill Snorkel": a novel bioelectrochemical approach to stimulate the oxidative biodegradation of petroleum hydrocarbons in sediments. The "Oil-Spill Snorkel" consists of a single conductive material (the snorkel) positioned suitably to create an electrochemical connection between the anoxic zone (the contaminated sediment) and the oxic zone (the overlying O2-containing water). The segment of the electrode buried within the sediment plays a role of anode, accepting electrons deriving from the oxidation of contaminants. Electrons flow through the snorkel up to the part exposed to the aerobic environment (the cathode), where they reduce oxygen to form water. Here we report the results of lab-scale microcosms setup with marine sediments and spiked with crude oil. Microcosms containing one or three graphite snorkels and controls (snorkel-free and autoclaved) were monitored for over 400 days. Collectively, the results of this study confirmed that the snorkels accelerate oxidative reactions taking place within the sediment, as documented by a significant 1.7-fold increase (p = 0.023, two-tailed t-test) in the cumulative oxygen uptake and 1.4-fold increase (p = 0.040) in the cumulative CO2 evolution in the microcosms containing three snorkels compared to snorkel-free controls. Accordingly, the initial rate of total petroleum hydrocarbons (TPH) degradation was also substantially enhanced. Indeed, while after 200 days of incubation a negligible degradation of TPH was noticed in snorkel-free controls, a significant reduction of 12 ± 1% (p = 0.004) and 21 ± 1% (p = 0.001) was observed in microcosms containing one and three snorkels, respectively. Although, the "Oil-Spill Snorkel" potentially represents a groundbreaking alternative to more expensive remediation options, further research efforts are needed to clarify factors and conditions affecting the snorkel-driven biodegradation processes and to identify suitable configurations for field applications.

No MeSH data available.


(A) Conceptual illustration of the “Oil-Spill Snorkel.” The segment of the electrode that is buried within the sediment serves as an anode, accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material up to the portion exposed to the aerobic environment (i.e., the cathode), where they reduce oxygen to form water. (B) Picture of the experimental setup.
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Figure 1: (A) Conceptual illustration of the “Oil-Spill Snorkel.” The segment of the electrode that is buried within the sediment serves as an anode, accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material up to the portion exposed to the aerobic environment (i.e., the cathode), where they reduce oxygen to form water. (B) Picture of the experimental setup.

Mentions: The aim of this study is to present the proof-of-concept of a novel bioelectrochemical approach to accelerate hydrocarbons biodegradation in anoxic marine sediment. The system, hereafter named “Oil-Spill Snorkel” is based on the “Microbial Electrochemical Snorkel” (MES) concept originally developed for the treatment of urban wastewaters (MFCs; Erable et al., 2011). The “Oil-Spill Snorkel” consists of a single conductive material (i.e., an electrode) positioned so as to create an electrochemical connection between an anoxic zone (e.g., the contaminated sediment) and an oxic zone (i.e., the overlying O2-containing water). The lower segment of the electrode, buried within the contaminated sediment, serves as the anode accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material to the portion exposed to the aerobic environment (i.e., the cathode) where they reduce oxygen to form water (Figure 1A; Erable et al., 2011). In principle, this configuration virtually eliminates the electric resistances resulting from electrode separation in conventional microbial fuel cells and other engineered bioelectrochemical systems. Overall, the “Oil-Spill Snorkel” aims at providing bacteria within the sediment access to a high redox potential electron acceptor (oxygen) and by so doing accelerating oxidative biodegradation processes. To our knowledge, this is the first time that a MES is applied for bioremediation purposes and specifically for the treatment of marine sediments contaminated by petroleum hydrocarbons.


The "Oil-Spill Snorkel": an innovative bioelectrochemical approach to accelerate hydrocarbons biodegradation in marine sediments.

Cruz Viggi C, Presta E, Bellagamba M, Kaciulis S, Balijepalli SK, Zanaroli G, Petrangeli Papini M, Rossetti S, Aulenta F - Front Microbiol (2015)

(A) Conceptual illustration of the “Oil-Spill Snorkel.” The segment of the electrode that is buried within the sediment serves as an anode, accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material up to the portion exposed to the aerobic environment (i.e., the cathode), where they reduce oxygen to form water. (B) Picture of the experimental setup.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4559663&req=5

Figure 1: (A) Conceptual illustration of the “Oil-Spill Snorkel.” The segment of the electrode that is buried within the sediment serves as an anode, accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material up to the portion exposed to the aerobic environment (i.e., the cathode), where they reduce oxygen to form water. (B) Picture of the experimental setup.
Mentions: The aim of this study is to present the proof-of-concept of a novel bioelectrochemical approach to accelerate hydrocarbons biodegradation in anoxic marine sediment. The system, hereafter named “Oil-Spill Snorkel” is based on the “Microbial Electrochemical Snorkel” (MES) concept originally developed for the treatment of urban wastewaters (MFCs; Erable et al., 2011). The “Oil-Spill Snorkel” consists of a single conductive material (i.e., an electrode) positioned so as to create an electrochemical connection between an anoxic zone (e.g., the contaminated sediment) and an oxic zone (i.e., the overlying O2-containing water). The lower segment of the electrode, buried within the contaminated sediment, serves as the anode accepting the electrons deriving from the microbiological oxidation of contaminants and other reduced species. Electrons flow through the conductive material to the portion exposed to the aerobic environment (i.e., the cathode) where they reduce oxygen to form water (Figure 1A; Erable et al., 2011). In principle, this configuration virtually eliminates the electric resistances resulting from electrode separation in conventional microbial fuel cells and other engineered bioelectrochemical systems. Overall, the “Oil-Spill Snorkel” aims at providing bacteria within the sediment access to a high redox potential electron acceptor (oxygen) and by so doing accelerating oxidative biodegradation processes. To our knowledge, this is the first time that a MES is applied for bioremediation purposes and specifically for the treatment of marine sediments contaminated by petroleum hydrocarbons.

Bottom Line: Electrons flow through the snorkel up to the part exposed to the aerobic environment (the cathode), where they reduce oxygen to form water.Here we report the results of lab-scale microcosms setup with marine sediments and spiked with crude oil.Collectively, the results of this study confirmed that the snorkels accelerate oxidative reactions taking place within the sediment, as documented by a significant 1.7-fold increase (p = 0.023, two-tailed t-test) in the cumulative oxygen uptake and 1.4-fold increase (p = 0.040) in the cumulative CO2 evolution in the microcosms containing three snorkels compared to snorkel-free controls.

View Article: PubMed Central - PubMed

Affiliation: Water Research Institute, National Research Council Rome, Italy.

ABSTRACT
This study presents the proof-of-concept of the "Oil-Spill Snorkel": a novel bioelectrochemical approach to stimulate the oxidative biodegradation of petroleum hydrocarbons in sediments. The "Oil-Spill Snorkel" consists of a single conductive material (the snorkel) positioned suitably to create an electrochemical connection between the anoxic zone (the contaminated sediment) and the oxic zone (the overlying O2-containing water). The segment of the electrode buried within the sediment plays a role of anode, accepting electrons deriving from the oxidation of contaminants. Electrons flow through the snorkel up to the part exposed to the aerobic environment (the cathode), where they reduce oxygen to form water. Here we report the results of lab-scale microcosms setup with marine sediments and spiked with crude oil. Microcosms containing one or three graphite snorkels and controls (snorkel-free and autoclaved) were monitored for over 400 days. Collectively, the results of this study confirmed that the snorkels accelerate oxidative reactions taking place within the sediment, as documented by a significant 1.7-fold increase (p = 0.023, two-tailed t-test) in the cumulative oxygen uptake and 1.4-fold increase (p = 0.040) in the cumulative CO2 evolution in the microcosms containing three snorkels compared to snorkel-free controls. Accordingly, the initial rate of total petroleum hydrocarbons (TPH) degradation was also substantially enhanced. Indeed, while after 200 days of incubation a negligible degradation of TPH was noticed in snorkel-free controls, a significant reduction of 12 ± 1% (p = 0.004) and 21 ± 1% (p = 0.001) was observed in microcosms containing one and three snorkels, respectively. Although, the "Oil-Spill Snorkel" potentially represents a groundbreaking alternative to more expensive remediation options, further research efforts are needed to clarify factors and conditions affecting the snorkel-driven biodegradation processes and to identify suitable configurations for field applications.

No MeSH data available.