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Wang S, Guo S. Effects of soil organic carbon metabolism on electro-bioremediation of petroleum-contaminated soil. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132180. [PMID: 37527589 DOI: 10.1016/j.jhazmat.2023.132180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/22/2023] [Accepted: 07/27/2023] [Indexed: 08/03/2023]
Abstract
Soil organic carbon (SOC) potentially interacts with microbial metabolism and may affect the degradation of petroleum-derived carbon (PDC) in the electro-bioremediation of petroleum-contaminated soil. This study evaluated the interactions among organic carbon, soil properties, and microbial communities to explore the role of SOC during the electro-bioremediation process. The results showed that petroleum degradation exerted superposition and synergistic electrokinetic and bioremediation effects, as exemplified by the EB and EB-PR tests, owing to the maintenance and enhancement of SOC utilization (P/S value), respectively. The highest P/S value (2.0-2.4) was found in the electrochemical oxidation zone due to low SOC consumption. In the biological oxidation zones, electric stimulation enhanced the degradation of PDC and SOC, with higher average P/S values than those of the Bio test. Soil pH, Eh, inorganic ions, and bioavailable petroleum fractions were the main factors reshaping the microbial communities. SOC metabolism effectively buffered the stress of environmental factors and pollutants while maintaining functional bacterial abundance, microbial alpha diversity, and community similarity, thus saving the weakened PDC biodegradation efficiency in the EB and EB-PR tests. The study of the effect of SOC metabolism on petroleum biodegradation contributes to the development of sustainable low-carbon electro-bioremediation technology.
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Affiliation(s)
- Sa Wang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang 110016, China.
| | - Shuhai Guo
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang 110016, China.
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2
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Zhang M, Wu B, Guo P, Wang S, Guo S. Bioremediation of polycyclic aromatic hydrocarbons contaminated soil under the superimposed electric field condition. CHEMOSPHERE 2021; 273:128723. [PMID: 33127102 DOI: 10.1016/j.chemosphere.2020.128723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 09/10/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
An innovative superimposed electric field (SEF) was designed with the aim to achieve uniform removal of polycyclic aromatic hydrocarbons (PAHs) in soil. Also the influence of SEF on the bioremediation efficiency of PAHs was investigated in compared with the common electric field (CEF). Five experiments were conducted in this study, namely EK-CEF (applied CEF), EKB-CEF (CEF enhanced bioremediation), EK-SEF (applied SEF), EKB-SEF (SEF enhanced bioremediation), and Bio (bioremediation). The results indicated that electric field with periodically reversed polarity could effectively prevent the occurrence of large changes in soil pH, temperature, and electric current. The electric field intensity of SEF was concentrated in the range of 0.5-1.5 V/cm, and the difference between the maximum and minimum PAHs removal percentage in EK-SEF was just 5.4%, in comparison to 14.8% in EK-CEF. The bioremediation promoting effect did not show significant difference between SEF and CEF. Compared to Bio, the removal percentages of the 5-ring and 6-ring PAHs attributed to the degrading bacteria were much higher in EKB-SEF and EKB-CEF. Moreover, the microbial number increased with the distance away from electrodes, and the microbial community changed correspondingly. All these would be resulted in differences removal efficiencies among different PAHs components. Despite its intrinsic advantages, the influence of SEF on soil physicochemical and biological properties needs further study.
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Affiliation(s)
- Meng Zhang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation By Bio-physicochemical Synergistic Process, Shenyang, 110016, China
| | - Bo Wu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation By Bio-physicochemical Synergistic Process, Shenyang, 110016, China
| | | | - Sa Wang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation By Bio-physicochemical Synergistic Process, Shenyang, 110016, China
| | - Shuhai Guo
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation By Bio-physicochemical Synergistic Process, Shenyang, 110016, China.
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Crognale S, Cocarta DM, Streche C, D’Annibale A. Development of laboratory-scale sequential electrokinetic and biological treatment of chronically hydrocarbon-impacted soils. N Biotechnol 2020; 58:38-44. [DOI: 10.1016/j.nbt.2020.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/06/2020] [Accepted: 04/11/2020] [Indexed: 01/04/2023]
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Zhang M, Guo P, Wu B, Guo S. Change in soil ion content and soil water-holding capacity during electro-bioremediation of petroleum contaminated saline soil. JOURNAL OF HAZARDOUS MATERIALS 2020; 387:122003. [PMID: 31901846 DOI: 10.1016/j.jhazmat.2019.122003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/14/2019] [Accepted: 12/30/2019] [Indexed: 06/10/2023]
Abstract
This study investigated changes in soil ion content and soil water-holding capacity during electro-bioremediation (EK-Bio) of petroleum contaminated saline soil (ion content of 3.92 g/kg). The results indicated that the soil ions surrounded the electrodes with increasing time, thus changing the soil water-holding capacity. According to the Van Genuchten model fitting results, the soil residual water content (θr) increased with the soil ion content, which represented a capacity decrease of the soil water supply. At the end of the EK-Bio experiment, the θr values in the soil near (site A) and far from (site B) the electrodes were 19.1 % and 12.1 %, where the soil ion content was 7.92 g/kg and 0.55 g/kg, respectively. The ion aggregation process significantly impacted the growth of soil microbial. The bacteria numbers decreased when the soil ion content was high (7.41 g/kg, site A) and low (0.84 g/kg, site B) after 70 days of treatment. The applied electric field significantly enhanced the bioremediation efficiency. However, the biodegradation promotion effect was the weakest at site A. The synergistic effect between the applied electric field and degrading bacteria was delayed.
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Affiliation(s)
- Meng Zhang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-Physicochemical Synergistic Process, Shenyang, 110016, China
| | | | - Bo Wu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-Physicochemical Synergistic Process, Shenyang, 110016, China
| | - Shuhai Guo
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-Physicochemical Synergistic Process, Shenyang, 110016, China.
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Shan Y, Harms H, Wick LY. Electric Field Effects on Bacterial Deposition and Transport in Porous Media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:14294-14301. [PMID: 30418019 DOI: 10.1021/acs.est.8b03648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bacterial deposition and transport are key to microbial ecology and biotechnological applications. We therefore tested whether electrokinetic forces (electroosmotic shear force ( FEOF), electrophoretic drag force ( FEP)) acting on bacteria may be used to control bacterial deposition during transport in laboratory percolation columns exposed to external direct current (DC) electric fields. For different bacteria, yet similar experimental conditions we observed that DC fields either enhanced or reduced bacterial deposition efficiencies (α) relative to DC-free controls. By calculating the DLVO force of colloidal interactions, FEOF, FEP, and the hydraulic shear forces acting on single cells at a collector surface we found that DC-induced changes of α correlated to | FEOF| to | FEP| ratios: If | FEOF| > | FEP|, α was clearly increased and if | FEOF| < | FEP| α was clearly decreased. Our findings allow for better prediction of the forces acting on a bacterium at collector surface and, hence, the electrokinetic control of microbial deposition in natural and manmade ecosystems.
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Affiliation(s)
- Yongping Shan
- UFZ - Helmholtz Centre for Environmental Research , Department of Environmental Microbiology , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Hauke Harms
- UFZ - Helmholtz Centre for Environmental Research , Department of Environmental Microbiology , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Lukas Y Wick
- UFZ - Helmholtz Centre for Environmental Research , Department of Environmental Microbiology , Permoserstrasse 15 , 04318 Leipzig , Germany
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Zhang M, Guo S, Li F, Wu B. Distribution of ion contents and microorganisms during the electro-bioremediation of petroleum-contaminated saline soil. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:1141-1149. [PMID: 28738174 DOI: 10.1080/10934529.2017.1342499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This study investigated the distribution of ion contents and microorganisms during the electro-bioremediation (EK-Bio) of petroleum-contaminated saline soil. The results showed that soil ions tend to accumulate around the electrodes, and the concentration was correlated with the distance from the electrodes. The average soil ion content was 7.92 g/kg around the electrodes (site A) and 0.55 g/kg at the furthest distance from the electrodes (site B) after 112 days of treatment, while the initial average content was 3.92 g/kg. Smooth linear (R2 = 0.98) loss of soil ions was observed at site C, which was closer to the electrodes than site B, and had a final average soil ion content of 1.96 g/kg. The dehydrogenase activity was much higher in EK-Bio test soil than in the Bio test soil after 28 days of treatment, and followed the order: site C > site B > site A. However, the soil dehydrogenase activity dropped continuously when the soil ion reached very high and low concentrations at sites A and B. The soil microbial community varied in sample sites that had different ion contents, and the soil microbial diversity followed the order: site C > site B > site A. The applied electric field clearly enhanced the biodegradation efficiency for soil petroleum contaminants. However, the biodegradation promotion effects were weakening in soils where the ion contents were extremely high and low (sites A and B). These results can provide useful information for EK-Bioremediation of organic-contaminated saline soil.
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Affiliation(s)
- Meng Zhang
- a Institute of Applied Ecology , Chinese Academy of Sciences , Shenyang , P. R. China
- b Institute of Applied Ecology, Chinese Academy of Sciences, University of Chinese Academy of Sciences , Beijing , P. R. China
- c National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process , Shenyang , P. R. China
| | - Shuhai Guo
- a Institute of Applied Ecology , Chinese Academy of Sciences , Shenyang , P. R. China
- c National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process , Shenyang , P. R. China
| | - Fengmei Li
- a Institute of Applied Ecology , Chinese Academy of Sciences , Shenyang , P. R. China
- c National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process , Shenyang , P. R. China
| | - Bo Wu
- a Institute of Applied Ecology , Chinese Academy of Sciences , Shenyang , P. R. China
- c National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process , Shenyang , P. R. China
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Dykstra CM, Pavlostathis SG. Methanogenic Biocathode Microbial Community Development and the Role of Bacteria. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5306-5316. [PMID: 28368570 DOI: 10.1021/acs.est.6b04112] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The cathode microbial community of a methanogenic bioelectrochemical system (BES) is key to the efficient conversion of carbon dioxide (CO2) to methane (CH4) with application to biogas upgrading. The objective of this study was to compare the performance and microbial community composition of a biocathode inoculated with a mixed methanogenic (MM) culture to a biocathode inoculated with an enriched hydrogenotrophic methanogenic (EHM) culture, developed from the MM culture following pre-enrichment with H2 and CO2 as the only externally supplied electron donor and carbon source, respectively. Using an adjacent Ag/AgCl reference electrode, biocathode potential was poised at -0.8 V (versus SHE) using a potentiostat, with the bioanode acting as the counter electrode. When normalized to cathode biofilm biomass, the methane production in the MM- and EHM-biocathode was 0.153 ± 0.010 and 0.586 ± 0.029 mmol CH4/mg biomass-day, respectively. This study showed that H2/CO2 pre-enriched inoculum enhanced biocathode CH4 production, although the archaeal communities in both biocathodes converged primarily (86-100%) on a phylotype closely related to Methanobrevibacter arboriphilus. The bacterial community of the MM-biocathode was similar to that of the MM inoculum but was enriched in Spirochaetes and other nonexoelectrogenic, fermentative Bacteria. In contrast, the EHM-biocathode bacterial community was enriched in Proteobacteria, exoelectrogens, and putative producers of electron shuttle mediators. Similar biomass levels were detected in the MM- and EHM-biocathodes. Thus, although the archaeal communities were similar in the two biocathodes, the difference in bacterial community composition was likely responsible for the 3.8-fold larger CH4 production rate observed in the EHM-biocathode. Roles for abundant OTUs identified in the biofilm and inoculum cultures were highlighted on the basis of previous reports.
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Affiliation(s)
- Christy M Dykstra
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Spyros G Pavlostathis
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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8
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Pedersen KB, Lejon T, Jensen PE, Ottosen LM. Degradation of oil products in a soil from a Russian Barents hot-spot during electrodialytic remediation. SPRINGERPLUS 2016; 5:168. [PMID: 27026865 PMCID: PMC4766144 DOI: 10.1186/s40064-016-1882-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 02/16/2016] [Indexed: 11/28/2022]
Abstract
A highly oil-polluted soil from Krasnoe in North-West Russia was used to investigate the degradation of organic pollutants during electrodialytic remediation. Removal efficiencies were up to 70 % for total hydrocarbons (THC) and up to 65 % for polyaromatic hydrocarbons (PAH). Relatively more of the lighter PAH compounds and THC fractions were degraded. A principal component analysis (PCA) revealed a difference in the distribution of PAH compounds after the remediation. The observed clustering of experiments in the PCA scores plot was assessed to be related to the stirring rate. Multivariate analysis of the experimental settings and final concentrations in the 12 experiments revealed that the stirring rate of the soil suspension was by far the most important parameter for the remediation for both THC and PAH. Light was the second most important variable for PAH and seems to influence degradation. The experimental variables current density and remediation time did not significantly influence the degradation of the organic pollutants. Despite current density not influencing the remediation, there is potential for degrading organic pollutants during electrodialytic removal of heavy metals, as long as a stirred set-up is applied. Depending on remediation objectives, further optimisation may be needed in order to develop efficient remediation strategies.
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Affiliation(s)
- Kristine B Pedersen
- Department of Chemistry, University of Tromsø, The Arctic University of Norway, Postbox 6050, 9037 Langnes, Tromsø, Norway
| | - Tore Lejon
- Department of Chemistry, University of Tromsø, The Arctic University of Norway, Postbox 6050, 9037 Langnes, Tromsø, Norway
| | - Pernille E Jensen
- Department of Civil Engineering, Arctic Technology Centre, Technical University of Denmark, Brovej Building 118, 2800 Lyngby, Denmark
| | - Lisbeth M Ottosen
- Department of Civil Engineering, Arctic Technology Centre, Technical University of Denmark, Brovej Building 118, 2800 Lyngby, Denmark
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Isolation and characterization of heavy polycyclic aromatic hydrocarbon-degrading bacteria adapted to electrokinetic conditions. Biodegradation 2015; 27:1-13. [PMID: 26615425 DOI: 10.1007/s10532-015-9750-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in artificially contaminated soils. The results showed that strains PB4 (Pseudomonas fluorescens) and FB6 (Kocuria sp.) were the most efficient heavy PAH degraders under electrokinetic conditions. They were re-inoculated into a polluted soil from an industrial site with a PAH concentration of 184.95 mg kg(-1). Compared to the experiments without an electric field, the degradation capability of Pseudomonas fluorescens and Kocuria sp. was enhanced in the industrially polluted soil under electrokinetic conditions. The degradation extents of total PAHs were increased by 15.4 and 14.0% in the electrokinetic PB4 and FB6 experiments (PB4 + EK and FB6 + EK) relative to the PB4 and FB6 experiments without electrokinetic conditions (PB4 and FB6), respectively. These results indicated that P. fluorescens and Kocuria sp. could efficiently degrade heavy PAHs under electrokinetic conditions and have the potential to be used for the electro-bioremediation of PAH-contaminated soil, especially if the soil is contaminated with heavy PAHs.
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Qin J, Sun X, Liu Y, Berthold T, Harms H, Wick LY. Electrokinetic control of bacterial deposition and transport. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5663-5671. [PMID: 25844535 DOI: 10.1021/es506245y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Microbial biofilms can cause severe problems in technical installations where they may give rise to microbially influenced corrosion and clogging of filters and membranes or even threaten human health, e.g. when they infest water treatment processes. There is, hence, high interest in methods to prevent microbial adhesion as the initial step of biofilm formation. In environmental technology it might be desired to enhance bacterial transport through porous matrices. This motivated us to test the hypothesis that the attractive interaction energy allowing cells to adhere can be counteracted and overcome by the shear force induced by electroosmotic flow (EOF, i.e. the water flow over surfaces exposed to a weak direct current (DC) electric field). Applying EOF of varying strengths we quantified the deposition of Pseudomonas fluorescens Lp6a in columns containing glass collectors and on a quartz crystal microbalance. We found that the presence of DC reduced the efficiency of initial adhesion and bacterial surface coverage by >85%. A model is presented which quantitatively explains the reduction of bacterial adhesion based on the extended Derjaguin, Landau, Verwey, and Overbeek (XDLVO) theory of colloid stability and the EOF-induced shear forces acting on a bacterium. We propose that DC fields may be used to electrokinetically regulate the interaction of bacteria with surfaces in order to delay initial adhesion and biofilm formation in technical installations or to enhance bacterial transport in environmental matrices.
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Affiliation(s)
- Jinyi Qin
- †Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Saxony, Germany
| | - Xiaohui Sun
- ‡Department of Civil and Environmental Engineering, 3-133 Markin/CNRL Natural Resources Engineering Facility, University of Alberta, Edmonton, Alberta T6G 2W2, Canada
| | - Yang Liu
- ‡Department of Civil and Environmental Engineering, 3-133 Markin/CNRL Natural Resources Engineering Facility, University of Alberta, Edmonton, Alberta T6G 2W2, Canada
| | - Tom Berthold
- †Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Saxony, Germany
| | - Hauke Harms
- †Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Saxony, Germany
| | - Lukas Y Wick
- †Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Saxony, Germany
- ‡Department of Civil and Environmental Engineering, 3-133 Markin/CNRL Natural Resources Engineering Facility, University of Alberta, Edmonton, Alberta T6G 2W2, Canada
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11
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Gill RT, Harbottle MJ, Smith JWN, Thornton SF. Electrokinetic-enhanced bioremediation of organic contaminants: a review of processes and environmental applications. CHEMOSPHERE 2014; 107:31-42. [PMID: 24875868 DOI: 10.1016/j.chemosphere.2014.03.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/18/2014] [Accepted: 03/03/2014] [Indexed: 06/03/2023]
Abstract
There is current interest in finding sustainable remediation technologies for the removal of contaminants from soil and groundwater. This review focuses on the combination of electrokinetics, the use of an electric potential to move organic and inorganic compounds, or charged particles/organisms in the subsurface independent of hydraulic conductivity; and bioremediation, the destruction of organic contaminants or attenuation of inorganic compounds by the activity of microorganisms in situ or ex situ. The objective of the review is to examine the state of knowledge on electrokinetic bioremediation and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. It discusses the mechanisms of electrokinetic bioremediation in the subsurface environment at different micro and macroscales, the influence of environmental processes on electrokinetic phenomena and the design options available for application to the field scale. The review also presents results from a modelling exercise to illustrate the effectiveness of electrokinetics on the supply electron acceptors to a plume scale scenario where these are limiting. Current research needs include analysis of electrokinetic bioremediation in more representative environmental settings, such as those in physically heterogeneous systems in order to gain a greater understanding of the controlling mechanisms on both electrokinetics and bioremediation in those scenarios.
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Affiliation(s)
- R T Gill
- Groundwater Protection and Restoration Group, University of Sheffield, Department of Civil & Structural Engineering, Kroto Research Institute, Broad Lane, Sheffield S3 7HQ, UK.
| | - M J Harbottle
- Institute of Environment and Sustainability, Cardiff University, School of Engineering, Queen's Buildings, The Parade, Cardiff CF24 3AA, UK
| | - J W N Smith
- Shell Global Solutions, Lange Kleiweg 40, 2288 GK Rijswijk, The Netherlands; Groundwater Protection and Restoration Group, University of Sheffield, Department of Civil & Structural Engineering, Kroto Research Institute, Broad Lane, Sheffield S3 7HQ, UK
| | - S F Thornton
- Groundwater Protection and Restoration Group, University of Sheffield, Department of Civil & Structural Engineering, Kroto Research Institute, Broad Lane, Sheffield S3 7HQ, UK
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Effect of a direct electric current on the activity of a hydrocarbon-degrading microorganism culture used as the flushing liquid in soil remediation processes. Sep Purif Technol 2014. [DOI: 10.1016/j.seppur.2014.01.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Li F, Guo S, Hartog N. Electrokinetics-enhanced biodegradation of heavy polycyclic aromatic hydrocarbons in soil around iron and steel industries. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.08.055] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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15
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Wick LY, Buchholz F, Fetzer I, Kleinsteuber S, Härtig C, Shi L, Miltner A, Harms H, Pucci GN. Responses of soil microbial communities to weak electric fields. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:4886-4893. [PMID: 20663541 DOI: 10.1016/j.scitotenv.2010.06.048] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 06/22/2010] [Accepted: 06/22/2010] [Indexed: 05/29/2023]
Abstract
Electrokinetically stimulated bioremediation of soils (electro-bioremediation) requires that the application of weak electric fields has no negative effect on the contaminant degrading microbial communities. This study evaluated the hypothesis that weak direct electric current (DC) fields per se do not negatively influence the physiology and composition of soil microbial communities given that secondary electrokinetic phenomena such as soil pH changes and temperatures are minimized. Mildly buffered, water-saturated laboratory mesocosms with agricultural soil were subjected for 34 days to a constant electric field (X=1.4 V cm(-1); J approximately 1.0 mA cm(-2)) and the spatiotemporal changes of soil microbial communities assessed by fingerprints of phospholipids fatty acids (PLFA) and terminal restriction fragment length polymorphisms (T-RFLP) of bacterial 16S rRNA genes. DC-induced electrolysis of the pore water led to pH changes (<1.5 pH units) in the immediate vicinity of the electrodes and concomitant distinct soil microbial community changes. By contrast, DC-treated bulk soil distant to the electrodes showed no pH changes and developed similar PLFA- and T-RFLP-fingerprints as control soil in the absence of DC. Our data suggest that the presence of an electric field, if suitably applied, will not influence the composition and physiology of soil microbial communities and hence not affect their potential to biodegrade contaminants.
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Affiliation(s)
- Lukas Y Wick
- UFZ, Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig, Germany.
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Kim SH, Han HY, Lee YJ, Kim CW, Yang JW. Effect of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:3162-3168. [PMID: 20452646 DOI: 10.1016/j.scitotenv.2010.03.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 03/17/2010] [Accepted: 03/23/2010] [Indexed: 05/29/2023]
Abstract
Electrokinetic remediation has been successfully used to remove organic contaminants and heavy metals within soil. The electrokinetic process changes basic soil properties, but little is known about the impact of this remediation technology on indigenous soil microbial activities. This study reports on the effects of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. The main removal mechanism of diesel was electroosmosis and most of the bacteria were transported by electroosmosis. After 25 days of electrokinetic remediation (0.63 mA cm(-2)), soil pH developed from pH 3.5 near the anode to pH 10.8 near the cathode. The soil pH change by electrokinetics reduced microbial cell number and microbial diversity. Especially the number of culturable bacteria decreased significantly and only Bacillus and strains in Bacillales were found as culturable bacteria. The use of EDTA as an electrolyte seemed to have detrimental effects on the soil microbial activity, particularly in the soil near the cathode. On the other hand, the soil dehydrogenase activity was enhanced close to the anode and the analysis of microbial community structure showed the increase of several microbial populations after electrokinetics. It is thought that the main causes of changes in microbial activities were soil pH and direct electric current. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology if soil parameters, electric current, and electrolyte are suitably controlled based on the understanding of interaction between electrokinetics, contaminants, and indigenous microbial community.
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Affiliation(s)
- Seong-Hye Kim
- Nano Environmental Engineering Lab, Dept. of Chemical & Biomolecular Engineering, KAIST, 335 Gwahangno, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea
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Shi L, Müller S, Harms H, Wick LY. Effect of electrokinetic transport on the vulnerability of PAH-degrading bacteria in a model aquifer. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2008; 30:177-82. [PMID: 18253840 DOI: 10.1007/s10653-008-9146-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 10/08/2007] [Indexed: 05/15/2023]
Abstract
There has been increasing interest in employing electro-bioremediation, a hybrid technology of bioremediation and electrokinetics, to overcome the low bioavailability of hydrophobic organic contaminants (HOC) by homogenizing sorption-retarded HOC and immobilised microorganisms. Present electro-remediation approaches mainly aim at macroscale pollutant extraction and tend to neglect possible impacts of direct current (DC) on the physiology of microorganisms. The effect of weak electric fields (X = 1 V cm(-1)) on the fitness of electrokinetically dispersed fluorene-degrading Sphingomonas sp. LB126 in bench-scale model aquifers was investigated by flow cytometry using propidium iodide (PI) as an indicator that distinguishes between PI-permeable (cells with porous membranes, i.e. dead or vulnerable) and PI-impermeable bacteria. After 15.5 h of DC treatment 56% of all cells recovered were dispersed at the centimetre scale relative to 29% in the absence of DC. There was no overall negative effect of the 15.5-h DC treatment on cell vulnerability, as 7.0% of the DC-treated bacteria exhibited PI-staining compared to 6.5% of the control population. Minor differences were observed in the subpopulation that had been mobilised by electroosmosis with an approximately twofold increase in the percentage of PI-stained cells relative to the control. Enhanced PI staining did not correlate with reduced culturability of the cells on rich-medium agar plates. Relative to the control, DC-treated cells mobilised by electroosmosis were threefold more culturable, confirming earlier data that that PI-cell membrane permeability does not always indicate reduced viability of oligotrophic environmental bacteria. Our findings suggest that electrokinetics is a valuable mechanism to transport viable and culturable polycyclic aromatic hydrocarbon (PAH)-degrading bacteria in soil or sediments.
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Affiliation(s)
- Lei Shi
- Department of Environmental Microbiology, UFZ Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany
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