1
|
Sartirana D, Zanotti C, Palazzi A, Pietrini I, Frattini P, Franzetti A, Bonomi T, Rotiroti M. Assessing data variability in groundwater quality monitoring of contaminated sites through factor analysis and multiple linear regression models. JOURNAL OF CONTAMINANT HYDROLOGY 2025; 269:104471. [PMID: 39631170 DOI: 10.1016/j.jconhyd.2024.104471] [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: 08/29/2024] [Revised: 11/15/2024] [Accepted: 11/26/2024] [Indexed: 12/07/2024]
Abstract
Monitoring of long-term contaminant concentrations trends is essential to verify that attenuation processes are effectively occurring at a site. However, monitoring data are often affected by extreme variability which prevents the identification of clear concentration trends. The variability is higher in long-screened monitoring wells, which are currently used at many contaminated sites, although it has been known since the 1980s that monitoring data from long-screened wells can be biased. Understanding the factors that may influence the variability of monitoring data is pivotal. To this end, following hydrochemical conceptual modelling using a multi-method approach, the variability of hydrocarbon concentrations from fully screened monitoring wells was assessed over eleven years at a former oil refinery located in Northern Italy. The proposed methodology combined factor analysis with multiple linear regression models. Results pointed out a higher variability in hydrocarbon concentrations at the plume fringe and a lower variability at the plume source and core. 44-46 % of the total variability in measured hydrocarbon concentrations is due to "intrinsic plume heterogeneity", related to the three-dimensional structure of a contaminant plume, which becomes thinner at the edge, creating a vertical heterogeneity of redox conditions at the plume fringe. This variability, expressed as increasing concentrations of sulfate and decreasing concentrations of methane, represents a background variability that cannot be reduced by improving sampling procedures. The remaining 56-54 % of the total variability may be due to the non-standardization of some purging and sampling operations, such as pump intake position, purging and sampling time/flow rates and variations in the analytical methods. This finding suggests that monitoring improvements in fully screened wells by standardizing all purging/sampling operations or using sampling techniques that can reduce the actual screen length (e.g., packers or separation/dual pumping techniques) would reduce data variability by more than half.
Collapse
Affiliation(s)
- Davide Sartirana
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy.
| | - Chiara Zanotti
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy
| | - Alice Palazzi
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy
| | - Ilaria Pietrini
- Environmental and Biological Laboratories, Eni S.p.A., San Donato Milanese, Italy
| | - Paola Frattini
- Hydrogeology and Groundwater Modelling, Eni Rewind S.p.A., San Donato Milanese, Italy
| | - Andrea Franzetti
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy
| | - Tullia Bonomi
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy
| | - Marco Rotiroti
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza Della Scienza 1, 20126 Milan, Italy
| |
Collapse
|
2
|
Pinel-Cabello M, Wasmund K, Soder-Walz JM, Vega M, Rosell M, Marco-Urrea E. Divergent dual C-H isotopic fractionation pattern during anaerobic biodegradation of toluene within Aromatoleum species under nitrate-reducing conditions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 361:124823. [PMID: 39197649 DOI: 10.1016/j.envpol.2024.124823] [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: 05/02/2024] [Revised: 07/22/2024] [Accepted: 08/25/2024] [Indexed: 09/01/2024]
Abstract
Toluene is a pollutant frequently detected in contaminated groundwater, mostly due to leakage from underground gasoline storage tanks and pipeline ruptures. Multi-element compound-specific isotope analysis provides a framework to understand transformation processes and design efficient remediation strategies. In this study, we enriched an anaerobic bacterial culture derived from a BTEX-contaminated aquifer that couples toluene and phenol oxidation with nitrate reduction and the concomitant production of carbon dioxide and biomass. The 16S rRNA gene amplicon data indicated that the toluene-degrading consortium was dominated by an Aromatoleum population (87 ± 2 % relative abundance), and metagenome sequencing confirmed that the genome of this Aromatoleum sp. encoded glycyl-radical enzyme benzylsuccinate synthase (BssABC) and phenylphospate synthase (PpsA1BC) homologous genes involved in the first step of toluene and phenol transformation, respectively. Carbon and hydrogen isotopic fractionation were εbulk, C = - 3.5 ± 0.6 ‰ and εrp, H = - 85 ± 11 ‰, respectively, leading to a dual C-H isotope slope of ΛH/C = 26 ± 2. This value fits with a previously reported value for a consortium dominated by an Azoarcus species (ΛH/C = 19 ± 5) but differs from that reported for Aromatoleum aromaticum (ΛH/C = 14 ± 1), both of which grow with toluene under nitrate-reducing conditions. Overall, this suggests the existence of different BssABC enzymes with different mechanistic motifs even within the same Aromatoleum genus.
Collapse
Affiliation(s)
- Maria Pinel-Cabello
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Kenneth Wasmund
- School of Biological Sciences, University of Portsmouth, Portsmouth, UK
| | - Jesica M Soder-Walz
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Maria Vega
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Mònica Rosell
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), c/ Martí Franquès s/n, 08028, Barcelona, Spain
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain.
| |
Collapse
|
3
|
An S, Kim SH, Woo H, Choi JW, Yun ST, Chung J, Lee S. Groundwater-level fluctuation effects on petroleum hydrocarbons in vadose zones and their potential risks: Laboratory studies. JOURNAL OF HAZARDOUS MATERIALS 2024; 463:132837. [PMID: 37890385 DOI: 10.1016/j.jhazmat.2023.132837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/10/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
Despite the role of the vadose zone protecting groundwater from contamination, the non-stationarity in this zone makes it difficult to predict the behavior of petroleum hydrocarbons (PH) therein. In laboratory soil columns with sandy and sandy loam soils, we simulated a vadose zone subjected to repeated groundwater-level fluctuation (GLF) to evaluate the behavior of PH under hydrodynamic conditions. The GLF vertically redistributed the PH, the extent of which was pronounced in the sandy soil with a high initial concentration due to the enhanced transport of the immiscible PH through the larger pores. The frequency of GLF did not show a substantial effect on the extent of PH redistribution but largely affected their attenuation. The greater GLF hindered PH volatilization by maintaining a high degree of water saturation, while the subsequent development of a local anaerobic regime inhibited biodegradation, which was more apparent in the sandy loam. Finally, a specific potential risk index was introduced to quantitatively compare the potential risk of PH contamination in different vadose zones exposed to GLF. Overall, the sandy soil contaminated with the higher total PH (TPH) concentration showed markedly higher potential risk indices (i.e., 18.4-29.0%), while the ones comprised of the sandy loam showed 0.6-4.9%, which increased under the greater number of GLF cycles.
Collapse
Affiliation(s)
- Seongnam An
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Sang Hyun Kim
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Heesoo Woo
- Geo-technical Team, ECO Solution Business Unit, SK Ecoplant, Seoul 03143, Republic of Korea
| | - Jae Woo Choi
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Seong-Taek Yun
- Department of Earth and Environmental Sciences, Korea University, Seoul 136-701, Republic of Korea
| | - Jaeshik Chung
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea.
| | - Seunghak Lee
- Water Cycle Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Energy and Environmental Technology, KIST School, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea; Graduate School of Energy and Environment (KU-KIST GREEN SCHOOL), Korea University, Seoul 02841, Republic of Korea.
| |
Collapse
|
4
|
Southwell RV, Hilton SL, Pearson JM, Hand LH, Bending GD. Water flow plays a key role in determining chemical biodegradation in water-sediment systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163282. [PMID: 37023820 DOI: 10.1016/j.scitotenv.2023.163282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 04/14/2023]
Abstract
Before agrochemicals can be registered and sold, the chemical industry is required to perform regulatory tests to assess their environmental persistence, using defined guidelines. Aquatic fate tests (e.g. OECD 308) lack environmental realism as they are conducted under dark conditions and in small-scale static systems, which can affect microbial diversity and functionality. In this study, water-sediment microflumes were used to investigate the impact of these deficiencies in environmental realism on the fate of the fungicide, isopyrazam. Although on a large-scale, these systems aimed to retain the key aspects of OECD 308 tests. Tests were carried out under both a non-UV light-dark cycle and continuous darkness and under both static and flowing water conditions, to investigate how light and water flow affect isopyrazam biodegradation pathways. In static systems, light treatment played a significant role, with faster dissipation in illuminated compared to dark microflumes (DT50s = 20.6 vs. 47.7 days). In flowing systems (DT50s = 16.8 and 15.3 days), light did not play a significant role in dissipation, which was comparable between the two light treatments, and faster than in dark static microflumes. Microbial phototroph biomass was significantly reduced by water flow in the illuminated systems, thereby reducing their contribution to dissipation. Comprehensive analysis of bacterial and eukaryotic community composition identified treatment specific changes following incubation, with light promoting relative abundance of Cyanobacteria and eukaryotic algae, and flow increasing relative abundance of fungi. We conclude that both water velocity and non-UV light increased isopyrazam dissipation, but the contribution of light depended on the flow conditions. These differences may have resulted from impacts on microbial communities and via mixing processes, particularly hyporheic exchange. Inclusion of both light and flow in studies could improve the extent they mimic natural environments and predict chemical environmental persistence, thus bridging the gap between laboratory and field studies.
Collapse
Affiliation(s)
- Rebecca V Southwell
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK; Product Safety, Jealott's Hill International Research Centre, Syngenta, Bracknell, Berkshire RG4 6EY, UK.
| | - Sally L Hilton
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| | - Jonathan M Pearson
- School of Engineering, Library Road, University of Warwick, Coventry CV4 7AL, UK
| | - Laurence H Hand
- Product Safety, Jealott's Hill International Research Centre, Syngenta, Bracknell, Berkshire RG4 6EY, UK
| | - Gary D Bending
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| |
Collapse
|
5
|
Castro AR, Martins G, Salvador AF, Cavaleiro AJ. Iron Compounds in Anaerobic Degradation of Petroleum Hydrocarbons: A Review. Microorganisms 2022; 10:2142. [PMID: 36363734 PMCID: PMC9695802 DOI: 10.3390/microorganisms10112142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 09/22/2023] Open
Abstract
Waste and wastewater containing hydrocarbons are produced worldwide by various oil-based industries, whose activities also contribute to the occurrence of oil spills throughout the globe, causing severe environmental contamination. Anaerobic microorganisms with the ability to biodegrade petroleum hydrocarbons are important in the treatment of contaminated matrices, both in situ in deep subsurfaces, or ex situ in bioreactors. In the latter, part of the energetic value of these compounds can be recovered in the form of biogas. Anaerobic degradation of petroleum hydrocarbons can be improved by various iron compounds, but different iron species exert distinct effects. For example, Fe(III) can be used as an electron acceptor in microbial hydrocarbon degradation, zero-valent iron can donate electrons for enhanced methanogenesis, and conductive iron oxides may facilitate electron transfers in methanogenic processes. Iron compounds can also act as hydrocarbon adsorbents, or be involved in secondary abiotic reactions, overall promoting hydrocarbon biodegradation. These multiple roles of iron are comprehensively reviewed in this paper and linked to key functional microorganisms involved in these processes, to the underlying mechanisms, and to the main influential factors. Recent research progress, future perspectives, and remaining challenges on the application of iron-assisted anaerobic hydrocarbon degradation are highlighted.
Collapse
Affiliation(s)
- Ana R. Castro
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Gilberto Martins
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Andreia F. Salvador
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Ana J. Cavaleiro
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| |
Collapse
|
6
|
Gharasoo M, Elsner M, Van Cappellen P, Thullner M. Pore-Scale Heterogeneities Improve the Degradation of a Self-Inhibiting Substrate: Insights from Reactive Transport Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:13008-13018. [PMID: 36069624 DOI: 10.1021/acs.est.2c01433] [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] [Indexed: 06/15/2023]
Abstract
In situ bioremediation is a common remediation strategy for many groundwater contaminants. It was traditionally believed that (in the absence of mixing-limitations) a better in situ bioremediation is obtained in a more homogeneous medium where the even distribution of both substrate and bacteria facilitates the access of a larger portion of the bacterial community to a higher amount of substrate. Such conclusions were driven with the typical assumption of disregarding substrate inhibitory effects on the metabolic activity of enzymes at high concentration levels. To investigate the influence of pore matrix heterogeneities on substrate inhibition, we use a numerical approach to solve reactive transport processes in the presence of pore-scale heterogeneities. To this end, a rigorous reactive pore network model is developed and used to model the reactive transport of a self-inhibiting substrate under both transient and steady-state conditions through media with various, spatially correlated, pore-size distributions. For the first time, we explore on the basis of a pore-scale model approach the link between pore-size heterogeneities and substrate inhibition. Our results show that for a self-inhibiting substrate, (1) pore-scale heterogeneities can consistently promote degradation rates at toxic levels, (2) the effect reverses when the concentrations fall to levels essential for microbial growth, and (3) an engineered combination of homogeneous and heterogeneous media can increase the overall efficiency of bioremediation.
Collapse
Affiliation(s)
- Mehdi Gharasoo
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig 04318, Germany
- Bundesanstalt für Gewässerkunde, Abteilung Quantitative Gewässerkunde, Am Mainzer Tor 1, Koblenz 56068, Germany
- Department of Earth and Environmental Sciences, Ecohydrology Research Group, University of Waterloo, 200 University Av W, Waterloo ON N2L3G1, Canada
| | - Martin Elsner
- Technical University of Munich, Chair of Analytical Chemistry and Water Chemistry, Marchioninistr. 17, Munich 81377, Germany
| | - Philippe Van Cappellen
- Department of Earth and Environmental Sciences, Ecohydrology Research Group, University of Waterloo, 200 University Av W, Waterloo ON N2L3G1, Canada
| | - Martin Thullner
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, Leipzig 04318, Germany
- Federal Institute for Geosciences and Natural Resources (BGR), Hannover 30655, Germany
| |
Collapse
|
7
|
Xia X, Stewart DI, Cheng L, Liu Y, Wang Y, Ding A. Variation of bacterial community and alkane monooxygenase gene abundance in diesel n-alkane contaminated subsurface environment under seasonal water table fluctuation. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 248:104017. [PMID: 35523047 DOI: 10.1016/j.jconhyd.2022.104017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/26/2022] [Accepted: 04/24/2022] [Indexed: 06/14/2023]
Abstract
n-Alkanes, the main component of diesel fuel, are common light non-aqueous phase liquids (LNAPLs) that threaten ecological security. The subsurface from vadose zone, through fluctuating zone, to saturated zone, is a critical multi-interface earth layer which significantly affects the biodegradation processes of n-alkanes. A pilot-scale diesel contaminated aquifer column experiment has been undertaken to investigate the variations of bacterial community and alkane monooxygenase (alkB) gene abundance in these zones due to water-table fluctuations. The n-alkanes formed a layer immediately above the water table, and when this was raised, they were carried upwards through the fluctuating zone into the vadose zone. Water content and n-alkanes component C10-C12 are main factors influencing bacterial community variation in the vadose zone, while C10-C12 is a key driving factor shaping bacterial community in the fluctuating zone. The most abundant bacterial phyla at all three zones were Proteobacteria, Firmicutes and Actinobacteria, but moisture-niche selection determined their relative abundance. The intermittent wetting cycle resulted in higher abundance of Proteobacteria, and lower abundance of Actinobacteria in the vadose and fluctuating zones in comparison to the control column with a static water-table. The abundances of the alkB gene variants were relatively uniform in different zones, probably because the bacterial populations harboring alkB gene are habituated to biogenic n-alkanes rather than responding to diesel fuel contamination. The variation in the bacterial populations with height due to moisture-niche selection had very little effect on the alkB gene abundance, possibly because numerous species in both phyla (Proteobacteria and Actinobacteria) carry an alkB gene variant. Nevertheless, the drop in the water table caused a short-term spike in alkB gene abundance in the saturated zone, which is most likely associated with transport of solutes or colloids from the fluctuating zone to bacteria species in the saturated zone, so a fluctuating water table could potentially increase n-alkane biodegradation function.
Collapse
Affiliation(s)
- Xuefeng Xia
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | | | - Lirong Cheng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Yueqiao Liu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Yingying Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, China.
| |
Collapse
|
8
|
Taxonomic and functional trait-based approaches suggest that aerobic and anaerobic soil microorganisms allow the natural attenuation of oil from natural seeps. Sci Rep 2022; 12:7245. [PMID: 35508504 PMCID: PMC9068923 DOI: 10.1038/s41598-022-10850-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/31/2022] [Indexed: 12/02/2022] Open
Abstract
Natural attenuation, involving microbial adaptation, helps mitigating the effect of oil contamination of surface soils. We hypothesized that in soils under fluctuating conditions and receiving oil from seeps, aerobic and anaerobic bacteria as well as fungi could coexist to efficiently degrade hydrocarbons and prevent the spread of pollution. Microbial community diversity was studied in soil longitudinal and depth gradients contaminated with petroleum seeps for at least a century. Hydrocarbon contamination was high just next to the petroleum seeps but this level drastically lowered from 2 m distance and beyond. Fungal abundance and alpha-diversity indices were constant along the gradients. Bacterial abundance was constant but alpha-diversity indices were lower next to the oil seeps. Hydrocarbon contamination was the main driver of microbial community assemblage. 281 bacterial OTUs were identified as indicator taxa, tolerant to hydrocarbon, potentially involved in hydrocarbon-degradation or benefiting from the degradation by-products. These taxa belonging to lineages of aerobic and anaerobic bacteria, have specific functional traits indicating the development of a complex community adapted to the biodegradation of petroleum hydrocarbons and to fluctuating conditions. Fungi are less impacted by oil contamination but few taxa should contribute to the metabolic complementary within the microbial consortia forming an efficient barrier against petroleum dissemination.
Collapse
|
9
|
Sun F, Mellage A, Wang Z, Bakkour R, Griebler C, Thullner M, Cirpka OA, Elsner M. Toward Improved Bioremediation Strategies: Response of BAM-Degradation Activity to Concentration and Flow Changes in an Inoculated Bench-Scale Sediment Tank. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:4050-4061. [PMID: 35263099 PMCID: PMC8988295 DOI: 10.1021/acs.est.1c05259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/24/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Compound-specific isotope analysis (CSIA) can reveal mass-transfer limitations during biodegradation of organic pollutants by enabling the detection of masked isotope fractionation. Here, we applied CSIA to monitor the adaptive response of bacterial degradation in inoculated sediment to low contaminant concentrations over time. We characterized Aminobacter sp. MSH1 activity in a flow-through sediment tank in response to a transient supply of elevated 2,6-dichlorobenzamide (BAM) concentrations as a priming strategy and took advantage of an inadvertent intermittence to investigate the effect of short-term flow fluctuations. Priming and flow fluctuations yielded improved biodegradation performance and increased biodegradation capacity, as evaluated from bacterial activity and residual concentration time series. However, changes in isotope ratios in space and over time evidenced that mass transfer became increasingly limiting for degradation of BAM at low concentrations under such stimulated conditions, and that activity decreased further due to bacterial adaptation at low BAM (μg/L) levels. Isotope ratios, in conjunction with residual substrate concentrations, therefore helped identifying underlying limitations of biodegradation in such a stimulated system, offering important insight for future optimization of remediation schemes.
Collapse
Affiliation(s)
- Fengchao Sun
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstrasse 1 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Adrian Mellage
- Center
for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94, 72076, Tübingen, Germany
| | - Zhe Wang
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstrasse 1 85764 Neuherberg, Germany
- Chair
of Ecological Microbiology, University of
Bayreuth, Dr.-Hans-Frisch-Straße 1-3, 95448 Bayreuth, Germany
- School
of Life Sciences, Technical University of
Munich, Alte Akademie 8, 85354 Freising, Germany
| | - Rani Bakkour
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Christian Griebler
- Department
of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Martin Thullner
- Department
of Environmental Microbiology, UFZ—Helmholtz
Centre for Environmental Research, Permoserstr. 15, 30418 Leipzig, Germany
| | - Olaf A. Cirpka
- Center
for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94, 72076, Tübingen, Germany
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstrasse 1 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| |
Collapse
|
10
|
Hester ET, Santizo KY, Nida AA, Widdowson MA. Hyporheic transverse mixing zones and dispersivity: Laboratory and numerical experiments of hydraulic controls. JOURNAL OF CONTAMINANT HYDROLOGY 2021; 243:103885. [PMID: 34488177 DOI: 10.1016/j.jconhyd.2021.103885] [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: 03/26/2021] [Revised: 08/24/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Mixing of surface water and groundwater in shallow sediments is important to biogeochemical cycling and contaminant migration, and is often used to define the hyporheic zone. Yet knowledge of mixing processes in hyporheic zones is supported by surprisingly few rigorous lab or field observations, and differ from those in deeper groundwater by presence of enhanced head gradients, sediment heterogeneity, and temporal fluctuations. In a laboratory sediment (sand) tank we photographed a conservative dye to analyze transverse mixing zones between upwelling groundwater and bidirectional hyporheic exchange flows. We then conducted numerical modeling to investigate processes behind observed phenomena and estimate dispersivities. We found that transverse mixing zones were thin (i.e. mixing thickness measured in direction of steepest concentration gradient, δ, less than 5 cm), consistent with a small calibrated transverse dispersivity (~0.1 mm) and prior lab studies conducted at similar scales. In steady-state experiments and simulations, δ and estimated dispersion coefficients increased with the surface water head drop driving exchange flows. Given relatively constant deeper groundwater heads, increased Δh led to increased mixing zone length for both steady-state and transient conditions, indicating larger bedforms or weaker gaining conditions enhance subsurface mixing. However, Peclet number and flux-related dilution index simultaneously increased and decreased, respectively, indicating that enhancement of subsurface advection outpaced that of dispersion. In transient experiments and simulations, δ was greater than for steady-state, probably from temporary addition of longitudinal dispersion. During transient experiments, δ exhibited temporal noise, perhaps due to the mixing zone moving past varying patterns of sediment packing. Our results provide basic knowledge of mixing zone behavior in hyporheic zones with implications for hyporheic zone definitions, solute transport, mixing-dependent reaction, and water quality.
Collapse
Affiliation(s)
- Erich T Hester
- The Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, 200 Patton Hall, Blacksburg, VA 24061, United States of America.
| | - Katherine Y Santizo
- The Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, 200 Patton Hall, Blacksburg, VA 24061, United States of America
| | - Abenezer A Nida
- The Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, 200 Patton Hall, Blacksburg, VA 24061, United States of America
| | - Mark A Widdowson
- The Charles E. Via, Jr. Department of Civil and Environmental Engineering, Virginia Tech, 200 Patton Hall, Blacksburg, VA 24061, United States of America
| |
Collapse
|
11
|
Sun F, Mellage A, Gharasoo M, Melsbach A, Cao X, Zimmermann R, Griebler C, Thullner M, Cirpka OA, Elsner M. Mass-Transfer-Limited Biodegradation at Low Concentrations-Evidence from Reactive Transport Modeling of Isotope Profiles in a Bench-Scale Aquifer. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7386-7397. [PMID: 33970610 PMCID: PMC8173607 DOI: 10.1021/acs.est.0c08566] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Organic contaminant degradation by suspended bacteria in chemostats has shown that isotope fractionation decreases dramatically when pollutant concentrations fall below the (half-saturation) Monod constant. This masked isotope fractionation implies that membrane transfer is slow relative to the enzyme turnover at μg L-1 substrate levels. Analogous evidence of mass transfer as a bottleneck for biodegradation in aquifer settings, where microbes are attached to the sediment, is lacking. A quasi-two-dimensional flow-through sediment microcosm/tank system enabled us to study the aerobic degradation of 2,6-dichlorobenzamide (BAM), while collecting sufficient samples at the outlet for compound-specific isotope analysis. By feeding an anoxic BAM solution through the center inlet port and dissolved oxygen (DO) above and below, strong transverse concentration cross-gradients of BAM and DO yielded zones of low (μg L-1) steady-state concentrations. We were able to simulate the profiles of concentrations and isotope ratios of the contaminant plume using a reactive transport model that accounted for a mass-transfer limitation into bacterial cells, where apparent isotope enrichment factors *ε decreased strongly below concentrations around 600 μg/L BAM. For the biodegradation of organic micropollutants, mass transfer into the cell emerges as a bottleneck, specifically at low (μg L-1) concentrations. Neglecting this effect when interpreting isotope ratios at field sites may lead to a significant underestimation of biodegradation.
Collapse
Affiliation(s)
- Fengchao Sun
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, Neuherberg 85764, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, Munich 81377, Germany
| | - Adrian Mellage
- Center
for Applied Geoscience, University of Tübingen, Schnarrenbergstrasse 94−96, Tübingen 72076, Germany
| | - Mehdi Gharasoo
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, Neuherberg 85764, Germany
- Department
of Earth and Environmental Sciences, Ecohydrology, University of Waterloo, 200 University Avenue West, Waterloo N2L 3G1, Canada
| | - Aileen Melsbach
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, Neuherberg 85764, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, Munich 81377, Germany
| | - Xin Cao
- Joint
Mass Spectrometry Centre, Comprehensive
Molecular Analytics (CMA) Cooperation Group Helmholtz Zentrum, Gmunderstrasse 37, Munich 81379, Germany
| | - Ralf Zimmermann
- Joint
Mass Spectrometry Centre, Comprehensive
Molecular Analytics (CMA) Cooperation Group Helmholtz Zentrum, Gmunderstrasse 37, Munich 81379, Germany
| | - Christian Griebler
- Department
of Functional and Evolutionary Ecology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
| | - Martin Thullner
- Department
of Environmental Microbiology, UFZ—Helmholtz
Centre for Environmental Research, Permoserstrasse 15, Leipzig 30418, Germany
| | - Olaf A. Cirpka
- Center
for Applied Geoscience, University of Tübingen, Schnarrenbergstrasse 94−96, Tübingen 72076, Germany
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, Neuherberg 85764, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, Munich 81377, Germany
- Phone: +49 89 2180-78232
| |
Collapse
|
12
|
Sun F, Peters J, Thullner M, Cirpka OA, Elsner M. Magnitude of Diffusion- and Transverse Dispersion-Induced Isotope Fractionation of Organic Compounds in Aqueous Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4772-4782. [PMID: 33729766 PMCID: PMC8154364 DOI: 10.1021/acs.est.0c06741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Determining whether aqueous diffusion and dispersion lead to significant isotope fractionation is important for interpreting the isotope ratios of organic contaminants in groundwater. We performed diffusion experiments with modified Stokes diaphragm cells and transverse-dispersion experiments in quasi-two-dimensional flow-through sediment tank systems to explore isotope fractionation for benzene, toluene, ethylbenzene, 2,6-dichlorobenzamide, and metolachlor at natural isotopic abundance. We observed very small to negligible diffusion- and transverse-dispersion-induced isotope enrichment factors (ε < -0.4 ‰), with changes in carbon and nitrogen isotope values within ±0.5‰ and ±1‰, respectively. Isotope effects of diffusion did not show a clear correlation with isotopologue mass with calculated power-law exponents β close to zero (0.007 < β < 0.1). In comparison to ions, noble gases, and labeled compounds, three aspects stand out. (i) If a mass dependence is derived from collision theory, then isotopologue masses of polyatomic molecules would be affected by isotopes of multiple elements resulting in very small expected effects. (ii) However, collisions do not necessarily lead to translational movement but can excite molecular vibrations or rotations minimizing the mass dependence. (iii) Solute-solvent interactions like H-bonds can further minimize the effect of collisions. Modeling scenarios showed that an inadequate model choice, or erroneous choice of β, can greatly overestimate the isotope fractionation by diffusion and, consequently, transverse dispersion. In contrast, available data for chlorinated solvent and gasoline contaminants at natural isotopic abundance suggest that in field scenarios, a potential additional uncertainty from aqueous diffusion or dispersion would add to current instrumental uncertainties on carbon or nitrogen isotope values (±1‰) with an additional ±1‰ at most.
Collapse
Affiliation(s)
- Fengchao Sun
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, 81377 Munich, Germany
| | - Jan Peters
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
- Center
for Applied Geoscience, University of Tübingen, Hölderlinstrasse12, 72074 Tübingen, Germany
| | - Martin Thullner
- Department
of Environmental Microbiology, UFZ—Helmholtz
Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Olaf A. Cirpka
- Center
for Applied Geoscience, University of Tübingen, Hölderlinstrasse12, 72074 Tübingen, Germany
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, 81377 Munich, Germany
- Phone: +49 89 2180-78232; (M.E.)
| |
Collapse
|
13
|
Hidalgo KJ, Teramoto EH, Soriano AU, Valoni E, Baessa MP, Richnow HH, Vogt C, Chang HK, Oliveira VM. Taxonomic and functional diversity of the microbiome in a jet fuel contaminated site as revealed by combined application of in situ microcosms with metagenomic analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 708:135152. [PMID: 31812384 DOI: 10.1016/j.scitotenv.2019.135152] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 06/10/2023]
Abstract
Natural attenuation represents all processes that govern contaminant mass removal, which mainly occurs via microbial degradation in the environment. Although this process is intrinsic its rate and efficiency depend on multiple factors. This study aimed to characterize the microbial taxonomic and functional diversity in different aquifer sediments collected in the saturated zone and in situ microcosms (BACTRAP®s) amended with hydrocarbons (13C-labeled and non-labeled benzene, toluene and naphthalene) using 16S rRNA gene and "shotgun" Illumina high throughput sequencing at a jet-fuel contaminated site. The BACTRAP®s were installed to assess hydrocarbon metabolism by native bacteria. Results indicated that Proteobacteria, Actinobacteria and Firmicutes were the most dominant phyla (~98%) in the aquifer sediment samples. Meanwhile, in the benzene- and toluene-amended BACTRAP®s the phyla Firmicutes and Proteobacteria accounted for about 90% of total community. In the naphthalene-amended BACTRAP®, members of the SR-FBR-L83 family (Order Ignavibacteriales) accounted for almost 80% of bacterial community. Functional annotation of metagenomes showed that only the sediment sample located at the source zone border and with the lowest BTEX concentration, has metabolic potential to degrade hydrocarbons aerobically. On the other hand, in situ BACTRAP®s allowed enrichment of hydrocarbon-degrading bacteria. Metagenomic data suggest that fumarate addition is the main mechanism for hydrocarbon activation of toluene. Also, indications for methylation, hydroxylation and carboxylation as activation mechanisms for benzene anaerobic conversion were found. After 120 days of exposure in the contaminated groundwater, the isotopic analysis of fatty acids extracted from BACTRAP®s demonstrated the assimilation of isotopic labeled compounds in the cells of microbes expressed by strong isotopic enrichment. We propose that the microbiota in this jet-fuel contaminated site has metabolic potential to degrade benzene and toluene by a syntrophic process, between members of the families Geobacteraceae and Peptococcaceae (genus Pelotomaculum), coupled to nitrate, iron and/or sulfate reduction.
Collapse
Affiliation(s)
- K J Hidalgo
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), Rua Monteiro Lobato 255, Cidade Universitária, Campinas, SP. ZIP 13083-862, Brazil.
| | - E H Teramoto
- Laboratory of Basin Studies (LEBAC), São Paulo State University (UNESP), Rio Claro, Av. 24A, 1515 ZIP 13506-900, Brazil
| | - A U Soriano
- PETROBRAS/ R&D Center (CENPES), Av. Horácio Macedo, 950. ZIP 21941-915 Ilha do Fundão, Rio de Janeiro, Brazil
| | - E Valoni
- PETROBRAS/ R&D Center (CENPES), Av. Horácio Macedo, 950. ZIP 21941-915 Ilha do Fundão, Rio de Janeiro, Brazil
| | - M P Baessa
- PETROBRAS/ R&D Center (CENPES), Av. Horácio Macedo, 950. ZIP 21941-915 Ilha do Fundão, Rio de Janeiro, Brazil
| | - H H Richnow
- Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstrasse 15 04318 Leipzig, Germany
| | - C Vogt
- Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research (UFZ), Permoserstrasse 15 04318 Leipzig, Germany
| | - H K Chang
- Laboratory of Basin Studies (LEBAC), São Paulo State University (UNESP), Rio Claro, Av. 24A, 1515 ZIP 13506-900, Brazil
| | - V M Oliveira
- Microbial Resources Division, Research Center for Chemistry, Biology and Agriculture (CPQBA), University of Campinas - UNICAMP, Paulínia, Brazil, Av. Alexandre Cazellato, 999, ZIP 13148-218, Brazil
| |
Collapse
|
14
|
Recent Advances in Experimental Studies of Steady-State Dilution and Reactive Mixing in Saturated Porous Media. WATER 2018. [DOI: 10.3390/w11010003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transverse dispersive mixing plays an important role in controlling natural attenuation of contaminant plumes and the performance of engineered remediation strategies. The extent of transverse mixing can be significantly affected by porous media heterogeneity and anisotropy. For instance, flow focusing in the high-permeability inclusions leads to an enhancement of dilution and reactive mixing in steady-state solute transport. Numerous modeling studies have been performed to understand the mechanism of conservative and reactive transport in homogeneous and complex heterogeneous porous media. However, experimental investigations are necessary to show an intuitive phenomenon and to validate the modeling results. This paper briefly reviews recent laboratory experimental studies on dilution and reactive mixing of steady-state transport in saturated homogeneous and heterogeneous porous media. In this context, setups and measuring techniques are described in pore-scale and Darcy-scale experiments. Parameters quantifying dilution and reactive mixing in the experiments are also introduced. Finally, we discuss the further experimental works necessary to deepen our understanding of dilution and reactive mixing in natural aquifers.
Collapse
|
15
|
Contaminant concentration versus flow velocity: drivers of biodegradation and microbial growth in groundwater model systems. Biodegradation 2018; 29:211-232. [PMID: 29492777 PMCID: PMC5943387 DOI: 10.1007/s10532-018-9824-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 02/23/2018] [Indexed: 11/07/2022]
Abstract
Aromatic hydrocarbons belong to the most abundant contaminants in groundwater systems. They can serve as carbon and energy source for a multitude of indigenous microorganisms. Predictions of contaminant biodegradation and microbial growth in contaminated aquifers are often vague because the parameters of microbial activity in the mathematical models used for predictions are typically derived from batch experiments, which don’t represent conditions in the field. In order to improve our understanding of key drivers of natural attenuation and the accuracy of predictive models, we conducted comparative experiments in batch and sediment flow-through systems with varying concentrations of contaminant in the inflow and flow velocities applying the aerobic Pseudomonas putida strain F1 and the denitrifying Aromatoleum aromaticum strain EbN1. We followed toluene degradation and bacterial growth by measuring toluene and oxygen concentrations and by direct cell counts. In the sediment columns, the total amount of toluene degraded by P. putida F1 increased with increasing source concentration and flow velocity, while toluene removal efficiency gradually decreased. Results point at mass transfer limitation being an important process controlling toluene biodegradation that cannot be assessed with batch experiments. We also observed a decrease in the maximum specific growth rate with increasing source concentration and flow velocity. At low toluene concentrations, the efficiencies in carbon assimilation within the flow-through systems exceeded those in the batch systems. In all column experiments the number of attached cells plateaued after an initial growth phase indicating a specific “carrying capacity” depending on contaminant concentration and flow velocity. Moreover, in all cases, cells attached to the sediment dominated over those in suspension, and toluene degradation was performed practically by attached cells only. The observed effects of varying contaminant inflow concentration and flow velocity on biodegradation could be captured by a reactive-transport model. By monitoring both attached and suspended cells we could quantify the release of new-grown cells from the sediments to the mobile aqueous phase. Studying flow velocity and contaminant concentrations as key drivers of contaminant transformation in sediment flow-through microcosms improves our system understanding and eventually the prediction of microbial biodegradation at contaminated sites.
Collapse
|
16
|
Schmidt SI, Cuthbert MO, Schwientek M. Towards an integrated understanding of how micro scale processes shape groundwater ecosystem functions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 592:215-227. [PMID: 28319709 DOI: 10.1016/j.scitotenv.2017.03.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/05/2017] [Accepted: 03/06/2017] [Indexed: 06/06/2023]
Abstract
Micro scale processes are expected to have a fundamental role in shaping groundwater ecosystems and yet they remain poorly understood and under-researched. In part, this is due to the fact that sampling is rarely carried out at the scale at which microorganisms, and their grazers and predators, function and thus we lack essential information. While set within a larger scale framework in terms of geochemical features, supply with energy and nutrients, and exchange intensity and dynamics, the micro scale adds variability, by providing heterogeneous zones at the micro scale which enable a wider range of redox reactions. Here we outline how understanding micro scale processes better may lead to improved appreciation of the range of ecosystems functions taking place at all scales. Such processes are relied upon in bioremediation and we demonstrate that ecosystem modelling as well as engineering measures have to take into account, and use, understanding at the micro scale. We discuss the importance of integrating faunal processes and computational appraisals in research, in order to continue to secure sustainable water resources from groundwater.
Collapse
Affiliation(s)
- Susanne I Schmidt
- Centre for Systems Biology, University of Birmingham, Birmingham, UK.
| | - Mark O Cuthbert
- Connected Waters Initiative Research Centre, UNSW Australia, 110 King Street, Manly Vale 2093, Australia; Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
| | - Marc Schwientek
- Center of Applied Geoscience, University of Tübingen, 72074 Tübingen, Germany
| |
Collapse
|
17
|
Kurt Z, Mack EE, Spain JC. Natural Attenuation of Nonvolatile Contaminants in the Capillary Fringe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10172-10178. [PMID: 27523982 DOI: 10.1021/acs.est.6b02525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
When anoxic polluted groundwater encounters the overlying vadose zone an oxic/anoxic interface is created, often near the capillary fringe. Biodegradation of volatile contaminants in the capillary fringe can prevent vapor migration. In contrast, the biodegradation of nonvolatile contaminants in the vadose zone has received comparatively little attention. Nonvolatile compounds do not cause vapor intrusion, but they still move with the groundwater and are major contaminants. Aniline (AN) and diphenylamine (DPA) are examples of toxic nonvolatile contaminants found often at dye and munitions manufacturing sites. In this study, we tested the hypothesis that bacteria can aerobically biodegrade AN and DPA in the capillary fringe and decrease the contaminant concentrations in the anoxic plume beneath the vadose zone. Laboratory multiport columns that represented the unsaturated zone were used to evaluate degradation of AN or DPA in contaminated water. The biodegradation fluxes of the contaminants were estimated to be 113 ± 26 mg AN·m(-2)·h(-1) and 76 ± 18 mg DPA·m(-2)·h(-1) in the presence of bacteria known to degrade AN and DPA. Oxygen and contaminant profiles along with enumeration of bacterial populations indicated that most of the biodegradation took place within the lower part of the capillary fringe. The results indicate that bacteria capable of contaminant biodegradation in the capillary fringe can create a sink for nonvolatile contaminants.
Collapse
Affiliation(s)
- Zohre Kurt
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States
- Institute of Scientific Research and High Technology Services , Calle Pullpn, Panamá, Panama
| | - E Erin Mack
- DuPont, Corporate Remediation Group, P.O. Box 6101, Glasgow 300, Newark, Delaware 19714-6101, United States
| | - Jim C Spain
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States
- Center for Environmental Diagnostics and Bioremediation, University of West Florida , Pensacola, Florida 32514-5751, United States
| |
Collapse
|
18
|
Hofmann R, Grösbacher M, Griebler C. Mini Sediment Columns and Two-Dimensional Sediment Flow-Through Microcosms: Versatile Experimental Systems for Studying Biodegradation of Organic Contaminants in Groundwater Ecosystems. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/8623_2016_210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
19
|
Dvorski SEM, Gonsior M, Hertkorn N, Uhl J, Müller H, Griebler C, Schmitt-Kopplin P. Geochemistry of Dissolved Organic Matter in a Spatially Highly Resolved Groundwater Petroleum Hydrocarbon Plume Cross-Section. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:5536-46. [PMID: 27152868 DOI: 10.1021/acs.est.6b00849] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
At numerous groundwater sites worldwide, natural dissolved organic matter (DOM) is quantitatively complemented with petroleum hydrocarbons. To date, research has been focused almost exclusively on the contaminants, but detailed insights of the interaction of contaminant biodegradation, dominant redox processes, and interactions with natural DOM are missing. This study linked on-site high resolution spatial sampling of groundwater with high resolution molecular characterization of DOM and its relation to groundwater geochemistry across a petroleum hydrocarbon plume cross-section. Electrospray- and atmospheric pressure photoionization (ESI, APPI) ultrahigh resolution mass spectrometry (FT-ICR-MS) revealed a strong interaction between DOM and reactive sulfur species linked to microbial sulfate reduction, i.e., the key redox process involved in contaminant biodegradation. Excitation emission matrix (EEM) fluorescence spectroscopy in combination with Parallel Factor Analysis (PARAFAC) modeling attributed DOM samples to specific contamination traits. Nuclear magnetic resonance (NMR) spectroscopy evaluated the aromatic compounds and their degradation products in samples influenced by the petroleum contamination and its biodegradation. Our orthogonal high resolution analytical approach enabled a comprehensive molecular level understanding of the DOM with respect to in situ petroleum hydrocarbon biodegradation and microbial sulfate reduction. The role of natural DOM as potential cosubstrate and detoxification reactant may improve future bioremediation strategies.
Collapse
Affiliation(s)
- Sabine E-M Dvorski
- Helmholtz Zentrum München-German Research Center for Environmental Health , Research Unit Analytical BioGeoChemistry, D-85764 Neuherberg, Germany
| | - Michael Gonsior
- University of Maryland Center for Environmental Science , Chesapeake Biological Laboratory, Solomons, Maryland 20688, United States
| | - Norbert Hertkorn
- Helmholtz Zentrum München-German Research Center for Environmental Health , Research Unit Analytical BioGeoChemistry, D-85764 Neuherberg, Germany
| | - Jenny Uhl
- Helmholtz Zentrum München-German Research Center for Environmental Health , Research Unit Analytical BioGeoChemistry, D-85764 Neuherberg, Germany
| | - Hubert Müller
- Helmholtz Zentrum München-German Research Center for Environmental Health , Institute of Groundwater Ecology, D-85764 Neuherberg, Germany
| | - Christian Griebler
- Helmholtz Zentrum München-German Research Center for Environmental Health , Institute of Groundwater Ecology, D-85764 Neuherberg, Germany
| | - Philippe Schmitt-Kopplin
- Helmholtz Zentrum München-German Research Center for Environmental Health , Research Unit Analytical BioGeoChemistry, D-85764 Neuherberg, Germany
- Technische Universität München , Chair of Analytical Food Chemistry, D-85354 Freising-Weihenstephan, Germany
| |
Collapse
|
20
|
Long-distance electron transfer by cable bacteria in aquifer sediments. ISME JOURNAL 2016; 10:2010-9. [PMID: 27058505 PMCID: PMC4939269 DOI: 10.1038/ismej.2015.250] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/19/2015] [Accepted: 11/25/2015] [Indexed: 11/23/2022]
Abstract
The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous ‘cable bacteria' has recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic–anoxic interfaces in aquifer sediments, where they provide a means for the direct recycling of sulfate by electron transfer over 1–2-cm distance. Sediments were taken from a hydrocarbon-contaminated aquifer, amended with iron sulfide and saturated with water, leaving the sediment surface exposed to air. Steep geochemical gradients developed in the upper 3 cm, showing a spatial separation of oxygen and sulfide by 9 mm together with a pH profile characteristic for sulfur oxidation by LDET. Bacterial filaments, which were highly abundant in the suboxic zone, were identified by sequencing of 16S rRNA genes and fluorescence in situ hybridization (FISH) as cable bacteria belonging to the Desulfobulbaceae. The detection of similar Desulfobulbaceae at the oxic–anoxic interface of fresh sediment cores taken at a contaminated aquifer suggests that LDET may indeed be active at the capillary fringe in situ.
Collapse
|
21
|
Khan AM, Wick LY, Harms H, Thullner M. Biodegradation of vapor-phase toluene in unsaturated porous media: Column experiments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 211:325-331. [PMID: 26774779 DOI: 10.1016/j.envpol.2016.01.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/05/2016] [Accepted: 01/05/2016] [Indexed: 06/05/2023]
Abstract
Biodegradation of organic chemicals in the vapor phase of soils and vertical flow filters has gained attention as promising approach to clean up volatile organic compounds (VOC). The drivers of VOC biodegradation in unsaturated systems however still remain poorly understood. Here, we analyzed the processes controlling aerobic VOC biodegradation in a laboratory setup mimicking the unsaturated zone above a shallow aquifer. The setup allowed for diffusive vapor-phase transport and biodegradation of three VOC: non-deuterated and deuterated toluene as two compounds of highly differing biodegradability but (nearly) identical physical and chemical properties, and MTBE as (at the applied experimental conditions) non-biodegradable tracer and internal control. Our results showed for toluene an effective microbial degradation within centimeter VOC transport distances despite high gas-phase diffusivity. Degradation rates were controlled by the reactivity of the compounds while oxic conditions were found everywhere in the system. This confirms hypotheses that vadose zone biodegradation rates can be extremely high and are able to prevent the outgassing of VOC to the atmosphere within a centimeter range if compound properties and site conditions allow for sufficiently high degradation rates.
Collapse
Affiliation(s)
- Ali M Khan
- Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Lukas Y Wick
- Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany.
| | - Hauke Harms
- Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Martin Thullner
- Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research, Leipzig, Germany
| |
Collapse
|
22
|
Hack N, Reinwand C, Abbt-Braun G, Horn H, Frimmel FH. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 183:40-54. [PMID: 26529301 DOI: 10.1016/j.jconhyd.2015.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 10/13/2015] [Accepted: 10/21/2015] [Indexed: 06/05/2023]
Abstract
Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.
Collapse
Affiliation(s)
- Norman Hack
- Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany.
| | - Christian Reinwand
- Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany
| | - Gudrun Abbt-Braun
- Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany
| | - Harald Horn
- Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany
| | - Fritz H Frimmel
- Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institute, Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany
| |
Collapse
|
23
|
Meckenstock RU, Elsner M, Griebler C, Lueders T, Stumpp C, Aamand J, Agathos SN, Albrechtsen HJ, Bastiaens L, Bjerg PL, Boon N, Dejonghe W, Huang WE, Schmidt SI, Smolders E, Sørensen SR, Springael D, van Breukelen BM. Biodegradation: Updating the concepts of control for microbial cleanup in contaminated aquifers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7073-81. [PMID: 26000605 DOI: 10.1021/acs.est.5b00715] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Biodegradation is one of the most favored and sustainable means of removing organic pollutants from contaminated aquifers but the major steering factors are still surprisingly poorly understood. Growing evidence questions some of the established concepts for control of biodegradation. Here, we critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates. Furthermore, we discuss if the absence of specific degrader populations can explain poor biodegradation. We propose updated perspectives on the controls of biodegradation in contaminant plumes. These include the plume fringe concept, transport limitations, and transient conditions as currently underestimated processes affecting biodegradation.
Collapse
Affiliation(s)
- Rainer U Meckenstock
- †University of Duisburg-Essen, Biofilm Centre, Universitätsstrasse 5, 45141 Essen, Germany
| | - Martin Elsner
- ○Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Christian Griebler
- ○Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Tillmann Lueders
- ○Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Christine Stumpp
- ○Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany
| | - Jens Aamand
- ‡Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Spiros N Agathos
- §Laboratory of Bioengineering; Earth and Life Institute (ELI); Université Catholique de Louvain; Place Croix du Sud 2, L7.05.19, B-1348 Louvain-la-Neuve, Belgium
| | - Hans-Jørgen Albrechtsen
- ∥Department of Environmental Engineering, Miljoevej, building 113, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Leen Bastiaens
- ⊥Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
| | - Poul L Bjerg
- ∥Department of Environmental Engineering, Miljoevej, building 113, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Nico Boon
- ∇University of Gent, LabMET, Coupure Links 653, 9000 Ghent, Belgium
| | - Winnie Dejonghe
- ⊥Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
| | - Wei E Huang
- ◆Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, United Kingdom
| | - Susanne I Schmidt
- ¶CSB Centre for Systems Biology, School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston B15 2TT, United Kingdom
| | - Erik Smolders
- ∞Division Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Sebastian R Sørensen
- ‡Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Dirk Springael
- ∞Division Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium
| | - Boris M van Breukelen
- #Department of Earth Sciences, VU University Amsterdam, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands
| |
Collapse
|
24
|
Mellage A, Eckert D, Grösbacher M, Inan AZ, Cirpka OA, Griebler C. Dynamics of suspended and attached aerobic toluene degraders in small-scale flow-through sediment systems under growth and starvation conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7161-9. [PMID: 26009808 DOI: 10.1021/es5058538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The microbially mediated reactions, that are responsible for field-scale natural attenuation of organic pollutants, are governed by the concurrent presence of a degrading microbial community, suitable energy and carbon sources, electron acceptors, as well as nutrients. The temporal lack of one of these essential components for microbial activity, arising from transient environmental conditions, might potentially impair in situ biodegradation. This study presents results of small scale flow-through experiments aimed at ascertaining the effects of substrate-starvation periods on the aerobic degradation of toluene by Pseudomonas putida F1. During the course of the experiments, concentrations of attached and mobile bacteria, as well as toluene and oxygen were monitored. Results from a fitted reactive-transport model, along with the observed profiles, show the ability of attached cells to survive substrate-starvation periods of up to four months and suggest a highly dynamic exchange between attached and mobile cells under growth conditions and negligible cell detachment under substrate-starvation conditions. Upon reinstatement of toluene, it was readily degraded without a significant lag period, even after a starvation period of 130 days. Our experimental and modeling results strongly suggest that aerobic biodegradation of BTEX-hydrocarbons at contaminated field sites is not hampered by intermittent starvation periods of up to four months.
Collapse
Affiliation(s)
- Adrian Mellage
- †University of Tübingen, Center for Applied Geoscience, Hölderlinstrasse, 12, 72074 Tübingen, Germany
- ‡now at: University of Waterloo, Department of Earth and Environmental Sciences, 200 University Ave. W, Waterloo, Ontario Canada N2L 3G1
| | - Dominik Eckert
- †University of Tübingen, Center for Applied Geoscience, Hölderlinstrasse, 12, 72074 Tübingen, Germany
| | - Michael Grösbacher
- §Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Ayse Z Inan
- §Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Olaf A Cirpka
- †University of Tübingen, Center for Applied Geoscience, Hölderlinstrasse, 12, 72074 Tübingen, Germany
| | - Christian Griebler
- §Helmholtz Zentrum München, Institute of Groundwater Ecology, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| |
Collapse
|
25
|
de Barros FPJ, Fiori A, Boso F, Bellin A. A theoretical framework for modeling dilution enhancement of non-reactive solutes in heterogeneous porous media. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 175-176:72-83. [PMID: 25795562 DOI: 10.1016/j.jconhyd.2015.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 01/16/2015] [Accepted: 01/30/2015] [Indexed: 06/04/2023]
Abstract
Spatial heterogeneity of the hydraulic properties of geological porous formations leads to erratically shaped solute clouds, thus increasing the edge area of the solute body and augmenting the dilution rate. In this study, we provide a theoretical framework to quantify dilution of a non-reactive solute within a steady state flow as affected by the spatial variability of the hydraulic conductivity. Embracing the Lagrangian concentration framework, we obtain explicit semi-analytical expressions for the dilution index as a function of the structural parameters of the random hydraulic conductivity field, under the assumptions of uniform-in-the-average flow, small injection source and weak-to-mild heterogeneity. Results show how the dilution enhancement of the solute cloud is strongly dependent on both the statistical anisotropy ratio and the heterogeneity level of the porous medium. The explicit semi-analytical solution also captures the temporal evolution of the dilution rate; for the early- and late-time limits, the proposed solution recovers previous results from the literature, while at intermediate times it reflects the increasing interplay between large-scale advection and local-scale dispersion. The performance of the theoretical framework is verified with high resolution numerical results and successfully tested against the Cape Cod field data.
Collapse
Affiliation(s)
- F P J de Barros
- Sonny Astani Dept. of Civil and Environmental Engineering, University of Southern California, Los Angeles, USA.
| | - A Fiori
- Dip. di Ingegneria, Universita di Roma Tre, Rome, Italy
| | - F Boso
- Dept. of Mechanical and Aerospace Engineering, University of California, La Jolla, San Diego, USA
| | - A Bellin
- Dept. of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy
| |
Collapse
|
26
|
Bahr A, Fischer A, Vogt C, Bombach P. Evidence of polycyclic aromatic hydrocarbon biodegradation in a contaminated aquifer by combined application of in situ and laboratory microcosms using (13)C-labelled target compounds. WATER RESEARCH 2015; 69:100-109. [PMID: 25437342 DOI: 10.1016/j.watres.2014.10.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 05/21/2023]
Abstract
The number of approaches to evaluate the biodegradation of polycyclic aromatic hydrocarbons (PAHs) within contaminated aquifers is limited. Here, we demonstrate the applicability of a novel method based on the combination of in situ and laboratory microcosms using (13)C-labelled PAHs as tracer compounds. The biodegradation of four PAHs (naphthalene, fluorene, phenanthrene, and acenaphthene) was investigated in an oxic aquifer at the site of a former gas plant. In situ biodegradation of naphthalene and fluorene was demonstrated using in situ microcosms (BACTRAP(®)s). BACTRAP(®)s amended with either [(13)C6]-naphthalene or [(13)C5/(13)C6]-fluorene (50:50) were incubated for a period of over two months in two groundwater wells located at the contaminant source and plume fringe, respectively. Amino acids extracted from BACTRAP(®)-grown cells showed significant (13)C-enrichments with (13)C-fractions of up to 30.4% for naphthalene and 3.8% for fluorene, thus providing evidence for the in situ biodegradation and assimilation of those PAHs at the field site. To quantify the mineralisation of PAHs, laboratory microcosms were set up with BACTRAP(®)-grown cells and groundwater. Naphthalene, fluorene, phenanthrene, or acenaphthene were added as (13)C-labelled substrates. (13)C-enrichment of the produced CO2 revealed mineralisation of between 5.9% and 19.7% for fluorene, between 11.1% and 35.1% for acenaphthene, between 14.2% and 33.1% for phenanthrene, and up to 37.0% for naphthalene over a period of 62 days. Observed PAH mineralisation rates ranged between 17 μg L(-1) d(-1) and 1639 μg L(-1) d(-1). The novel approach combining in situ and laboratory microcosms allowed a comprehensive evaluation of PAH biodegradation at the investigated field site, revealing the method's potential for the assessment of PAH degradation within contaminated aquifers.
Collapse
Affiliation(s)
- Arne Bahr
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Anko Fischer
- Isodetect GmbH, Deutscher Platz 5b, 04103 Leipzig, Germany
| | - Carsten Vogt
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Petra Bombach
- UFZ - Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, 04318 Leipzig, Germany; Isodetect GmbH, Deutscher Platz 5b, 04103 Leipzig, Germany.
| |
Collapse
|
27
|
Eckert D, Kürzinger P, Bauer R, Griebler C, Cirpka OA. Fringe-controlled biodegradation under dynamic conditions: quasi 2-D flow-through experiments and reactive-transport modeling. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 172:100-11. [PMID: 25496820 DOI: 10.1016/j.jconhyd.2014.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 11/01/2014] [Accepted: 11/11/2014] [Indexed: 05/12/2023]
Abstract
Biodegradation in contaminated aquifers has been shown to be most pronounced at the fringe of contaminant plumes, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. While physical mixing of contaminant and electron acceptor by transverse dispersion has been shown to be the major bottleneck for biodegradation in steady-state plumes, so far little is known on the effect of flow and transport dynamics (caused, e.g., by a seasonally fluctuating groundwater table) on biodegradation in these systems. Towards this end we performed experiments in quasi-two-dimensional flow-through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth, also maintenance and dormancy are important processes that affect biodegradation performance under transient environmental conditions and therefore deserve increased consideration in future reactive-transport modeling.
Collapse
Affiliation(s)
- Dominik Eckert
- University of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, Germany
| | - Petra Kürzinger
- Helmholtz Center Munich, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Robert Bauer
- Helmholtz Center Munich, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Christian Griebler
- Helmholtz Center Munich, Institute of Groundwater Ecology, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Olaf A Cirpka
- University of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, Germany.
| |
Collapse
|
28
|
Ballarini E, Beyer C, Bauer RD, Griebler C, Bauer S. Model based evaluation of a contaminant plume development under aerobic and anaerobic conditions in 2D bench-scale tank experiments. Biodegradation 2014; 25:351-71. [PMID: 24122285 DOI: 10.1007/s10532-013-9665-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
Abstract
The influence of transverse mixing on competitive aerobic and anaerobic biodegradation of a hydrocarbon plume was investigated using a two-dimensional, bench-scale flow-through laboratory tank experiment. In the first part of the experiment aerobic degradation of increasing toluene concentrations was carried out by the aerobic strain Pseudomonas putida F1. Successively, ethylbenzene (injected as a mixture of unlabeled and fully deuterium-labeled isotopologues) substituted toluene; nitrate was added as additional electron acceptor and the anaerobic denitrifying strain Aromatoleum aromaticum EbN1 was inoculated to study competitive degradation under aerobic /anaerobic conditions. The spatial distribution of anaerobic degradation was resolved by measurements of compound-specific stable isotope fractionation induced by the anaerobic strain as well as compound concentrations. A fully transient numerical reactive transport model was employed and calibrated using measurements of electron donors, acceptors and isotope fractionation. The aerobic phases of the experiment were successfully reproduced using a double Monod kinetic growth model and assuming an initial homogeneous distribution of P. putida F1. Investigation of the competitive degradation phase shows that the observed isotopic pattern cannot be explained by transverse mixing driven biodegradation only, but also depends on the inoculation process of the anaerobic strain. Transient concentrations of electron acceptors and donors are well reproduced by the model, showing its ability to simulate transient competitive biodegradation.
Collapse
|
29
|
Kurt Z, Mack EE, Spain JC. Biodegradation of cis-dichloroethene and vinyl chloride in the capillary fringe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:13350-13357. [PMID: 25329424 DOI: 10.1021/es503071m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Volatile chlorinated compounds are major pollutants in groundwater, and they pose a risk of vapor intrusion into buildings. Vapor intrusion can be prevented by natural attenuation in the vadose zone if biodegradation mechanisms can be established. In this study, we tested the hypothesis that bacteria can use cis-dichloroethene (cis-DCE) or vinyl chloride (VC) as an electron donor in the vadose zone. Anoxic water containing cis-DCE or VC was pumped continuously beneath laboratory columns that represented the vadose zone. Columns were inoculated with Polaromonas sp. strain JS666, which grows aerobically on cis-DCE, or with Mycobacterium sp. JS60 and Nocardiodes sp. JS614 that grow on VC. Complete biodegradation with fluxes of 84 ± 15 μmol of cis-DCE · m(-2) · hr(-1) and 218 ± 25 μmole VC·m(-2) · h(-1) within the 23 cm column indicated that microbial activities can prevent the migration of cis-DCE and VC vapors. Oxygen and volatile compound profiles along with enumeration of bacterial populations indicated that most of the biodegradation took place in the first 10 cm above the saturated zone within the capillary fringe. The results revealed that cis-DCE and VC can be biodegraded readily at the oxic/anoxic interfaces in the vadose zone if appropriate microbes are present.
Collapse
Affiliation(s)
- Zohre Kurt
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States
| | | | | |
Collapse
|
30
|
Fahrenfeld N, Cozzarelli IM, Bailey Z, Pruden A. Insights into biodegradation through depth-resolved microbial community functional and structural profiling of a crude-oil contaminant plume. MICROBIAL ECOLOGY 2014; 68:453-462. [PMID: 24760171 DOI: 10.1007/s00248-014-0421-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/07/2014] [Indexed: 06/03/2023]
Abstract
Small-scale geochemical gradients are a key feature of aquifer contaminant plumes, highlighting the need for functional and structural profiling of corresponding microbial communities on a similar scale. The purpose of this study was to characterize the microbial functional and structural diversity with depth across representative redox zones of a hydrocarbon plume and an adjacent wetland, at the Bemidji Oil Spill site. A combination of quantitative PCR, denaturing gradient gel electrophoresis, and pyrosequencing were applied to vertically sampled sediment cores. Levels of the methanogenic marker gene, methyl coenzyme-M reductase A (mcrA), increased with depth near the oil body center, but were variable with depth further downgradient. Benzoate degradation N (bzdN) hydrocarbon-degradation gene, common to facultatively anaerobic Azoarcus spp., was found at all locations, but was highest near the oil body center. Microbial community structural differences were observed across sediment cores, and bacterial classes containing known hydrocarbon degraders were found to be low in relative abundance. Depth-resolved functional and structural profiling revealed the strongest gradients in the iron-reducing zone, displaying the greatest variability with depth. This study provides important insight into biogeochemical characteristics in different regions of contaminant plumes, which will aid in improving models of contaminant fate and natural attenuation rates.
Collapse
Affiliation(s)
- Nicole Fahrenfeld
- Civil and Environmental Engineering, Rutgers, The State University of New Jersey, 96 Frelinghuysen Rd, Piscataway, NJ, USA,
| | | | | | | |
Collapse
|
31
|
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: 94] [Impact Index Per Article: 8.5] [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.
Collapse
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
| |
Collapse
|
32
|
Schmidt M, Wolfram D, Birkigt J, Ahlheim J, Paschke H, Richnow HH, Nijenhuis I. Iron oxides stimulate microbial monochlorobenzene in situ transformation in constructed wetlands and laboratory systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 472:185-193. [PMID: 24291561 DOI: 10.1016/j.scitotenv.2013.10.116] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 10/30/2013] [Accepted: 10/30/2013] [Indexed: 06/02/2023]
Abstract
Natural wetlands are transition zones between anoxic ground and oxic surface water which may enhance the (bio)transformation potential for recalcitrant chloro-organic contaminants due to the unique geochemical conditions and gradients. Monochlorobenzene (MCB) is a frequently detected groundwater contaminant which is toxic and was thought to be persistent under anoxic conditions. Furthermore, to date, no degradation pathways for anoxic MCB removal have been proven in the field. Hence, it is important to investigate MCB biodegradation in the environment, as groundwater is an important drinking water source in many European countries. Therefore, two pilot-scale horizontal subsurface-flow constructed wetlands, planted and unplanted, were used to investigate the processes in situ contributing to the biotransformation of MCB in these gradient systems. The wetlands were fed with anoxic MCB-contaminated groundwater from a nearby aquifer in Bitterfeld, Germany. An overall MCB removal was observed in both wetlands, whereas just 10% of the original MCB inflow concentration was detected in the ponds. In particular in the gravel bed of the planted wetland, MCB removal was highest in summer season with 73 ± 9% compared to the unplanted one with 40 ± 5%. Whereas the MCB concentrations rapidly decreased in the transition zone of unplanted gravel to the pond, a significant MCB removal was already determined in the anoxic gravel bed of the planted system. The investigation of hydro-geochemical parameters revealed that iron and sulphate reduction were relevant redox processes in both wetlands. In parallel, the addition of ferric iron or nitrate stimulated the mineralisation of MCB in laboratory microcosms with anoxic groundwater from the same source, indicating that the potential for anaerobic microbial degradation of MCB is present at the field site.
Collapse
Affiliation(s)
- Marie Schmidt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Diana Wolfram
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Jan Birkigt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Jörg Ahlheim
- Department of Groundwater Remediation, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Heidrun Paschke
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
| |
Collapse
|
33
|
Intrinsic potential for immediate biodegradation of toluene in a pristine, energy-limited aquifer. Biodegradation 2013; 25:325-36. [PMID: 24062165 DOI: 10.1007/s10532-013-9663-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 08/26/2013] [Indexed: 10/26/2022]
Abstract
Pristine and energy-limited aquifers are considered to have a low resistance and resilience towards organic pollution. An experiment in an indoor aquifer system revealed an unexpected high intrinsic potential for the attenuation of a short-term toluene contamination. A 30 h pulse of 486 mg of toluene, used as a model contaminant, and deuterated water (D2O) through an initially pristine, oxic, and organic carbon poor sandy aquifer revealed an immediate aerobic toluene degradation potential. Based on contaminant and tracer break-through curves, as well as mass balance analyses and reactive transport modelling, a contaminant removal of 40 % over a transport distance of only 4.2 m in less than one week of travel time was obtained. The mean first-order degradation rate constant was λ = 0.178 day(-1), corresponding to a half-life time constant T1/2 of 3.87 days. Toluene-specific stable carbon isotope analysis independently proved that the contaminant mass removal can be attributed to microbial biodegradation. Since average doubling times of indigenous bacterial communities were in the range of months to years, the aerobic biodegradation potential observed is assumed to be present and active in the pristine, energy-limited groundwater ecosystems at any time. Follow-up experiments and field studies will help to quantify the immediate natural attenuation potential of aquifers for selected priority contaminants and will try to identify the key-degraders within the autochthonous microbial communities.
Collapse
|
34
|
Kurt Z, Spain JC. Biodegradation of chlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene in the vadose zone. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6846-6854. [PMID: 23473240 DOI: 10.1021/es3049465] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Much of the microbial activity in nature takes place at interfaces, which are often associated with redox discontinuities. One example is the oxic/anoxic interface where polluted groundwater interacts with the overlying vadose zone. We tested whether microbes in the vadose zone can use synthetic chemicals as electron donors and thus protect the overlying air and buildings from groundwater pollutants. Samples from the vadose zone of a site contaminated with chlorobenzene (CB), 1,2-dichlorobenzene (12DCB), and 1,4-dichlorobenzene (14DCB) were packed in a multiport column to simulate the interface of the vadose zone with an underlying groundwater plume. A mixture of CB, 12DCB, and 14DCB in anoxic water was pumped continuously through the bottom of column to an outlet below the first sampling port to create an oxic/anoxic interface and a capillary fringe. Removal to below the detection limits by rapid biodegradation with rates of 21 ± 1 mg of CB • m(-2) • d(-1), 3.7 ± 0.5 mg of 12DCB • m(-2) • d(-1), and 7.4 ± 0.7 mg of 1.4 DCB • m(-2) • d(-1) indicated that natural attenuation in the capillary fringe can prevent the migration of CB, 12DCB, and 14DCB vapors. Enumeration of bacteria capable of degrading chlorobenzenes suggested that most of the biodegradation takes place within the first 10 cm above the saturated zone. Biodegradation also increased the upward flux of contaminants and thus enhanced their elimination from the underlying water. The results revealed a substantial biodegradation capacity for chlorinated aromatic compounds at the oxic/anoxic interface and illustrate the role of microbes in creating steep redox gradients.
Collapse
Affiliation(s)
- Zohre Kurt
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, United States
| | | |
Collapse
|
35
|
Tischer K, Kleinsteuber S, Schleinitz KM, Fetzer I, Spott O, Stange F, Lohse U, Franz J, Neumann F, Gerling S, Schmidt C, Hasselwander E, Harms H, Wendeberg A. Microbial communities along biogeochemical gradients in a hydrocarbon-contaminated aquifer. Environ Microbiol 2013; 15:2603-15. [DOI: 10.1111/1462-2920.12168] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 05/21/2013] [Accepted: 05/25/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Karolin Tischer
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | - Kathleen M. Schleinitz
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | | | - Oliver Spott
- Department of Soil Physics; Helmholtz Centre for Environmental Research - UFZ; Theodor-Lieser-Str. 4; 06120; Halle/Saale; Germany
| | - Florian Stange
- Federal Institute for Geosciences and Natural Resources; Stilleweg 2; 30655; Hannover; Germany
| | - Ute Lohse
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | | | | | - Sarah Gerling
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | - Christian Schmidt
- Department of Hydrogeology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | - Eyk Hasselwander
- G.U.T. Gesellschaft für Umweltsanierungs-Technologien mbH; Gerichtshain 1; 06217; Merseburg; Germany
| | - Hauke Harms
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| | - Annelie Wendeberg
- Department of Environmental Microbiology; Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15; 04318; Leipzig; Germany
| |
Collapse
|
36
|
Kurt Z, Shin K, Spain JC. Biodegradation of chlorobenzene and nitrobenzene at interfaces between sediment and water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11829-35. [PMID: 23035795 DOI: 10.1021/es302897j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Plumes of contaminated groundwater often pass through an oxic/anoxic interface when they discharge into surface water bodies. We tested the hypothesis that contaminants recalcitrant under anaerobic conditions but degradable under aerobic conditions can be biodegraded at the interface resulting in the protection of the overlying water. Flow-through columns containing sediment and water were used to evaluate degradation of synthetic organic compounds at the thin organic layer at the sediment/water interface. Sediment samples collected from several sites contaminated with nitrobenzene (NB) or chlorobenzene (CB) were tested for their biodegradation capacities in the columns. The biodegradation capacities of sediment in the columns were 2-4.2 g CB·m(-2)·d(-1) and 6.5 g NB·m(2)·d(-1). Bacteria able to carry out rapid and complete biodegradation of CB or NB were detected in the sediments prior to the experiments, which suggested the presence of an active microbial community at the contaminated sites. The results revealed robust biodegradation of toxic compounds migrating across the sediment/water interface and indicate that the biodegradation capacities were sufficient to eliminate transport of the contaminants to the overlying water in the field.
Collapse
Affiliation(s)
- Zohre Kurt
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0512, USA
| | | | | |
Collapse
|
37
|
Loyaux-Lawniczak S, Lehmann F, Ackerer P. Acid/base front propagation in saturated porous media: 2D laboratory experiments and modeling. JOURNAL OF CONTAMINANT HYDROLOGY 2012; 138-139:15-21. [PMID: 22784659 DOI: 10.1016/j.jconhyd.2012.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 05/23/2012] [Accepted: 06/04/2012] [Indexed: 06/01/2023]
Abstract
We perform laboratory scale reactive transport experiments involving acid-basic reactions between nitric acid and sodium hydroxide. A two-dimensional experimental setup is designed to provide continuous on-line measurements of physico-chemical parameters such as pH, redox potential (Eh) and electrical conductivity (EC) inside the system under saturated flow through conditions. The electrodes provide reliable values of pH and EC, while sharp fronts associated with redox potential dynamics could not be captured. Care should be taken to properly incorporate within a numerical model the mixing processes occurring inside the electrodes. The available observations are modeled through a numerical code based on the advection-dispersion equation. In this framework, EC is considered as a variable behaving as a conservative tracer and pH and Eh require solving the advection dispersion equation only once. The agreement between the computed and measured pH and EC is good even without recurring to parameters calibration on the basis of the experiments. Our findings suggest that the classical advection-dispersion equation can be used to interpret these kinds of experiments if mixing inside the electrodes is adequately considered.
Collapse
Affiliation(s)
- Stéphanie Loyaux-Lawniczak
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg, Université de Strasbourg/EOST-CNRS, 1 rue de Blessig, 67000 Strasbourg, France
| | | | | |
Collapse
|
38
|
Ballarini E, Bauer S, Eberhardt C, Beyer C. Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design. JOURNAL OF CONTAMINANT HYDROLOGY 2012; 134-135:22-36. [PMID: 22575873 DOI: 10.1016/j.jconhyd.2012.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 04/01/2012] [Accepted: 04/02/2012] [Indexed: 05/31/2023]
Abstract
Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications.
Collapse
Affiliation(s)
- E Ballarini
- Institute for Geosciences, University of Kiel, Ludewig-Meyn-Str. 10, D-24118 Kiel, Germany.
| | | | | | | |
Collapse
|
39
|
Kellermann C, Selesi D, Lee N, Hügler M, Esperschütz J, Hartmann A, Griebler C. Microbial CO2 fixation potential in a tar-oil-contaminated porous aquifer. FEMS Microbiol Ecol 2012; 81:172-87. [DOI: 10.1111/j.1574-6941.2012.01359.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 02/04/2023] Open
Affiliation(s)
- Claudia Kellermann
- Institute of Groundwater Ecology; Helmholtz Zentrum München; German Research Center for Environmental Health (GmbH); Neuherberg; Germany
| | - Draženka Selesi
- Institute of Groundwater Ecology; Helmholtz Zentrum München; German Research Center for Environmental Health (GmbH); Neuherberg; Germany
| | - Natuschka Lee
- Lehrstuhl für Mikrobiologie; Technische Universität München; Munich; Germany
| | - Michael Hügler
- DVGW - Technologiezentrum Wasser (TZW); Karlsruhe; Germany
| | - Jürgen Esperschütz
- Research Unit Environmental Genomics; Helmholtz Zentrum München; German Research Center for Environmental Health (GmbH); Neuherberg; Germany
| | - Anton Hartmann
- Research Unit Microbe-Plant Interactions; Helmholtz Zentrum München; German Research Center for Environmental Health (GmbH); Neuherberg; Germany
| | - Christian Griebler
- Institute of Groundwater Ecology; Helmholtz Zentrum München; German Research Center for Environmental Health (GmbH); Neuherberg; Germany
| |
Collapse
|
40
|
Jobelius C, Ruth B, Griebler C, Meckenstock RU, Hollender J, Reineke A, Frimmel FH, Zwiener C. Metabolites indicate hot spots of biodegradation and biogeochemical gradients in a high-resolution monitoring well. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:474-81. [PMID: 21121661 DOI: 10.1021/es1030867] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Anaerobic degradation processes play an important role in contaminated aquifers. To indicate active biodegradation processes signature metabolites can be used. In this study field samples from a high-resolution multilevel well in a tar oil-contaminated, anoxic aquifer were analyzed for metabolites by liquid chromatography-tandem mass spectrometry and time-of-flight mass spectrometry. In addition to already known specific degradation products of toluene, xylenes, and naphthalenes, the seldom reported degradation products benzothiophenemethylsuccinic acid (BTMS), benzofuranmethylsuccinic acid (BFMS), methylnaphthyl-2-methylsuccinic acid (MNMS), and acenaphthene-5-carboxylic acid (AC) could be identified (BFMS, AC) and tentatively identified (BTMS, MNMS). The occurrence of BTMS and BFMS clearly show that the fumarate addition pathway, known for toluene and methylnaphthalene, is also important for the anaerobic degradation of heterocyclic contaminants in aquifers. The molar concentration ratios of metabolites and their related parent compounds differ over a wide range which shows that there is no simple and consistent quantitative relation. However, generally higher ratios were found for the more recalcitrant compounds, which are putatively cometabolically degraded (e.g., 2-carboxybenzothiophene and acenaphthene-5-carboxylic acid), indicating an accumulation of these metabolites. Vertical concentration profiles of benzylsuccinic acid (BS) and methyl-benzylsuccinic acid (MBS) showed distinct peaks at the fringes of the toluene and xylene plume indicating hot spots of biodegradation activity and supporting the plume fringe concept. However, there are some compounds which show a different vertical distribution with the most prominent concentrations where also the precursor compounds peaked.
Collapse
Affiliation(s)
- Carsten Jobelius
- Engler-Bunte-Institut, Water Chemistry, Karlsruhe Institute of Technology (KIT), Germany
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Mohamed M, Hatfield K. Dimensionless parameters to summarize the influence of microbial growth and inhibition on the bioremediation of groundwater contaminants. Biodegradation 2010; 22:877-96. [DOI: 10.1007/s10532-010-9445-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 12/10/2010] [Indexed: 10/18/2022]
|
42
|
Brow CN, Johnson RO, Xu M, Johnson RL, Simon HM. Effects of cryogenic preservation and storage on the molecular characteristics of microorganisms in sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:8243-8247. [PMID: 20883032 DOI: 10.1021/es101641y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Sediment samples from a large physical-model aquifer and laboratory-generated samples were used to systematically assess the effects of whole-sample freezing on the integrity of biomolecules relevant to bioremediation. Impacts of freezing on DNA and RNA were assessed using quantitative polymerase chain reaction (PCR) as well as the community fingerprinting method, PCR single-strand conformation polymorphism (PCR-SSCP). We did not observe any significant degradation of a suite of genes and gene transcripts, including short-lived mRNA transcripts, from P. putida F1 or from B. subtilis JH642 in single-species samples, or from archaea in enrichment culture samples that also contained members of diverse bacterial phyla. Similarly, freezing did not change the relative abundance of dominant phylotypes in enrichment culture samples as measured by PCR-SSCP of bacterial 16S rDNA. Additionally, freezing and storage for 5 months at -80 °C did not affect the microbial community composition of samples from the model aquifer. Of even greater significance is that freezing and storage did not affect the relative abundance of 16S rRNA phylotypes, since in vivo rRNA content is often correlated with cellular growth rate. Thus, we conclude that cryogenic preservation and storage of intact sediment samples can be used for accurate molecular characterization of microbial populations and may facilitate high-resolution capture of biogeochemical interfaces important to bioremediation.
Collapse
Affiliation(s)
- Christina N Brow
- Division of Environmental and Biomolecular Systems, Oregon Health and Science University, Portland, Oregon, USA
| | | | | | | | | |
Collapse
|
43
|
Mohamed MM, Saleh NE, Sherif MM. Sensitivity of benzene natural attenuation to variations in kinetic and transport parameters in Liwa Aquifer, UAE. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2010; 84:443-449. [PMID: 20237911 DOI: 10.1007/s00128-010-9957-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 03/05/2010] [Indexed: 05/28/2023]
Abstract
Dissolved benzene was detected in the shallow unconfined Liwa aquifer (UAE). This aquifer represents the main freshwater source for a nearby residence camp area. A finite element model is used to simulate the fate, transport, and attenuation of the dissolved benzene plume to help decision makers assess natural attenuation as a viable remediation option. Sensitivity of benzene attenuation to uncertainties in the estimation of some of the kinetic and transport parameters is studied. It was found that natural attenuation is more sensitive to microbial growth rate and half saturation coefficients of both benzene and oxygen than initial biomass concentration and dispersivity coefficients. Increasing microbial growth rate by fourfold increased natural attenuation effectiveness after 40 years by 10%; while decreasing it by fourfold decreased natural attenuation effectiveness by 77%. On the other hand, increasing half saturation coefficient by fourfold decreased natural attenuation effectiveness by 46% in 40 years. Decreasing the same parameter fourfold caused natural attenuation effectiveness to increase by 9%.
Collapse
Affiliation(s)
- Mohamed M Mohamed
- Civil and Environmental Engineering Department, United Arab Emirates University, PO Box 17555, Al-Ain, UAE.
| | | | | |
Collapse
|
44
|
Elliott DR, Scholes JD, Thornton SF, Rizoulis A, Banwart SA, Rolfe SA. Dynamic changes in microbial community structure and function in phenol-degrading microcosms inoculated with cells from a contaminated aquifer. FEMS Microbiol Ecol 2010; 71:247-59. [DOI: 10.1111/j.1574-6941.2009.00802.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
45
|
Rolle M, Eberhardt C, Chiogna G, Cirpka OA, Grathwohl P. Enhancement of dilution and transverse reactive mixing in porous media: experiments and model-based interpretation. JOURNAL OF CONTAMINANT HYDROLOGY 2009; 110:130-142. [PMID: 19896237 DOI: 10.1016/j.jconhyd.2009.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 10/01/2009] [Accepted: 10/06/2009] [Indexed: 05/28/2023]
Abstract
Transport and natural attenuation of contaminant plumes in groundwater are often controlled by transverse dispersion. The extent of mixing between dissolved reaction partners at the fringe of a plume determines its length and depends strongly on the groundwater flow field. Transient flow conditions as well as the focusing of the flow in high-permeability zones may enhance transverse mixing of dissolved species and, therefore, create favorable conditions for the natural attenuation of contaminant plumes. The aim of the present study is to experimentally test the influence of these processes on solute mixing and to directly compare the results with those under analogous homogeneous and steady-state conditions. We have performed conservative and reactive tracer experiments in a quasi two-dimensional tank filled with glass beads of different sizes. The experiments have been carried out in both homogeneous and heterogeneous porous media under steady-state and transient (i.e. oscillating) flow fields. We used fluorescein as conservative tracer; whereas an alkaline solution (NaOH) was injected into ambient acidic water (HCl) in the reactive experiments. A pH indicator was added to the reacting solutions in order to visualize the emerging plume. We simulated the laboratory experiments with a numerical model and compared the outcomes of the model with the measured concentrations at the outlet of the tank and with the observed tracer plumes. Spatial moments, a newly defined flux-related dilution index, the product mass fluxes and the reaction enhancement factors were calculated to quantify the differences in mixing and reaction extent under various experimental conditions. The results show that flow focusing in heterogeneous porous media significantly enhances transverse mixing and mixing-controlled reactions, whereas temporally changing flow fields appear to be of minor importance.
Collapse
Affiliation(s)
- Massimo Rolle
- Center for Applied Geosciences, University of Tübingen, Sigwartstrasse 10, D-72076 Tübingen, Germany.
| | | | | | | | | |
Collapse
|
46
|
Prommer H, Anneser B, Rolle M, Einsiedl F, Griebler C. Biogeochemical and isotopic gradients in a BTEX/PAH contaminant plume: model-based interpretation of a high-resolution field data set. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:8206-12. [PMID: 19924945 DOI: 10.1021/es901142a] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A high spatial resolution data set documenting carbon and sulfur isotope fractionation at a tar oil-contaminated, sulfate-reducing field site was analyzed with a reactive transport model. Within a comprehensive numerical model, the study links the distinctive observed isotope depth profiles with the degradation of various monoaromatic and polycyclic aromatic hydrocarbon compounds (BTEX/PAHs) under sulfate-reducing conditions. In the numerical model, microbial dynamics were simulated explicitly and isotope fractionation was directly linked to the differential microbial uptake of lighter and heavier carbon isotopes during microbial growth. Measured depth profiles from a multilevel sampling well with high spatial resolution served as key constraints for the parametrization of the model simulations. The results of the numerical simulations illustrate particularly well the evolution of the isotope signature of toluene, which is the most rapidly degrading compound and the most important reductant at the site. The resulting depth profiles at the observation well show distinct differences between the small isotopic enrichment in the contaminant plume core and the much stronger enrichment of up to 3.3 per thousand at the plume fringes.
Collapse
|
47
|
Bauer RD, Rolle M, Bauer S, Eberhardt C, Grathwohl P, Kolditz O, Meckenstock RU, Griebler C. Enhanced biodegradation by hydraulic heterogeneities in petroleum hydrocarbon plumes. JOURNAL OF CONTAMINANT HYDROLOGY 2009; 105:56-68. [PMID: 19095328 DOI: 10.1016/j.jconhyd.2008.11.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 10/20/2008] [Accepted: 11/04/2008] [Indexed: 05/27/2023]
Abstract
In case of dissolved electron donors and acceptors, natural attenuation of organic contaminant plumes in aquifers is governed by hydrodynamic mixing and microbial activity. Main objectives of this work were (i) to determine whether aerobic and anaerobic biodegradation in porous sediments is controlled by transverse dispersion, (ii) to elucidate the effect of sediment heterogeneity on mixing and biodegradation, and (iii) to search for degradation-limiting factors. Comparative experiments were conducted in two-dimensional sediment microcosms. Aerobic toluene and later ethylbenzene degradation by Pseudomonas putida strain F1 was initially followed in a plume developing from oxic to anoxic conditions and later under steady-state mixing-controlled conditions. Competitive anaerobic degradation was then initiated by introduction of the denitrifying strain Aromatoleum aromaticum EbN1. In homogeneous sand, aerobic toluene degradation was clearly controlled by dispersive mixing. Similarly, under denitrifying conditions, microbial activity was located at the plume's fringes. Sediment heterogeneity caused flow focusing and improved the mixing of reactants. Independent from the electron accepting process, net biodegradation was always higher in the heterogeneous setting with a calculated efficiency plus of 23-100% as compared to the homogeneous setup. Flow and reactive transport model simulations were performed in order to interpret and evaluate the experimental results.
Collapse
Affiliation(s)
- Robert D Bauer
- Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, Institute of Groundwater Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Solvent stress response of the denitrifying bacterium "Aromatoleum aromaticum" strain EbN1. Appl Environ Microbiol 2008; 74:2267-74. [PMID: 18263750 DOI: 10.1128/aem.02381-07] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The denitrifying betaproteobacterium "Aromatoleum aromaticum" strain EbN1 degrades several aromatic compounds, including ethylbenzene, toluene, p-cresol, and phenol, under anoxic conditions. The hydrophobicity of these aromatic solvents determines their toxic properties. Here, we investigated the response of strain EbN1 to aromatic substrates at semi-inhibitory (about 50% growth inhibition) concentrations under two different conditions: first, during anaerobic growth with ethylbenzene (0.32 mM) or toluene (0.74 mM); and second, when anaerobic succinate-utilizing cultures were shocked with ethylbenzene (0.5 mM), toluene (1.2 mM), p-cresol (3.0 mM), and phenol (6.5 mM) as single stressors or as a mixture (total solvent concentration, 2.7 mM). Under all tested conditions impaired growth was paralleled by decelerated nitrate-nitrite consumption. Additionally, alkylbenzene-utilizing cultures accumulated poly(3-hydroxybutyrate) (PHB) up to 10% of the cell dry weight. These physiological responses were also reflected on the proteomic level (as determined by two-dimensional difference gel electrophoresis), e.g., up-regulation of PHB granule-associated phasins, cytochrome cd(1) nitrite reductase of denitrification, and several proteins involved in oxidative (e.g., SodB) and general (e.g., ClpB) stress responses.
Collapse
|