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Wang H, Zhu Y, Lu Y, Bu X, Zhu Q, Yuan S. Reduction capacity in the transmissive zones fueled by the embedded low-permeability lenses: Implications for contaminant transformation in heterogeneous aquifers. WATER RESEARCH 2024; 260:121955. [PMID: 38909424 DOI: 10.1016/j.watres.2024.121955] [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: 01/26/2024] [Revised: 06/13/2024] [Accepted: 06/16/2024] [Indexed: 06/25/2024]
Abstract
Redox conditions play a decisive role in regulating contaminant and nutrient transformation in groundwater. Here we quantitatively described and interpreted the temporal and spatial variations of aquifer reduction capacity formation in lens-embedded heterogeneous aquifers in 1-D columns. Experimental results indicated that the aquifer reduction capacity exported from the low-permeability lens permeated into the downstream sandy zones, where it subsequently accumulated and extended. Reactive transport modeling suggested that reduction capacity within the lens preferentially diffused to the transmissive zones around the lens-sand interface, and was then transported via convection to downstream transmissive zones. A low-permeability lens of the same volume, but more elongated in the flow direction, led to less concentrated reduction capacity but extended further downgradient from the lens. The increased flow velocity attenuated the maintenance of aquifer reduction capacity by enhancing mixing and diluting processes in the transmissive zones. The reduction zones formed downstream from the low-permeability lens were hotpots for resisting the oxidative perturbation by O2. This study highlights the important role of low-permeability lenses as large and long-term electron pools for the transmissive zones, and thus providing aquifer reduction capacity for contaminant transformation and remediation in heterogeneous aquifers.
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Affiliation(s)
- Hong Wang
- School of Environmental Studies, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, PR China
| | - Yonghui Zhu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, PR China
| | - Yuxi Lu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, PR China
| | - Xiaochuang Bu
- Ecohydrology Research Group, Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Qi Zhu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, PR China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, PR China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, PR China.
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2
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Zhang Y, Tong M, Lu Y, Zhao F, Zhang P, Wan Z, Li P, Yuan S, Wang Y, Kappler A. Directional long-distance electron transfer from reduced to oxidized zones in the subsurface. Nat Commun 2024; 15:6576. [PMID: 39097590 PMCID: PMC11297948 DOI: 10.1038/s41467-024-50974-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 07/26/2024] [Indexed: 08/05/2024] Open
Abstract
Electron transfer (ET) is the fundamental redox process of life and element cycling. The ET distance is normally as short as nanometers or micrometers in the subsurface. However, the redox gradient in the subsurface is as long as centimeters or even meters. This gap triggers an intriguing question whether directional long-distance ET from reduced to oxidized zones exists along the redox gradient. By using electron-donating capacity variation as a proxy of ET, we show that ET can last over 10 cm along the redox gradient in sediment columns, through a directional long-distance ET chain from reduced to oxidized zones constituted by a series of short-distance electron hopping reactions. Microbial and chemical processes synergistically mediate the long-distance ET chain, with an estimated flux of 6.73 μmol e-/cm2 per day. This directional long-distance ET represents an overlooked but important "remote" source of electrons for local biogeochemical and environmental processes.
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Affiliation(s)
- Yanting Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Man Tong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Yuxi Lu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Fengyi Zhao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Peng Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Zhenchen Wan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Ping Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, China.
| | - Yanxin Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Andreas Kappler
- Department of Geosciences, University of Tübingen, Tübingen, Germany
- Cluster of Excellence: EXC 2124: Controlling Microbes to Fight Infection, Tübingen, Germany
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3
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Wang X, Jones MR, Pan Z, Lu X, Deng Y, Zhu M, Wang Z. Trivalent manganese in dissolved forms: Occurrence, speciation, reactivity and environmental geochemical impact. WATER RESEARCH 2024; 263:122198. [PMID: 39098158 DOI: 10.1016/j.watres.2024.122198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/29/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
The cycling processes of elemental manganese (Mn), including the redox reactions of dissolved Mn(III) (dMn(III)), directly and indirectly influences the biogeochemical processes of many elements. Though increasing evidence indicates the widespread presence of dMn(III) mediates the fate of many elements, its role may be currently underestimated. There is both a lack of clear understanding of the historical research framework of dMn(III) and a systematic overview of its geochemical properties and detection methods. Therefore, the primary aim of this review is to outline the understanding of dMn(III) in multiple fields, including soil science, analytical chemistry, biochemistry, geochemistry, and water treatment, and summarize the formation pathways, species forms, and detection methods of dMn(III) in aquatic systems. This review considers how the characteristics of dMn(III), the intermediate formed in the single-electron reaction processes of Mn(II) oxidation and Mn(IV) reduction, determines its participation in environmental geochemical processes. Its widespread presence in diverse water systems and active redox properties coupling with various elements confirm its significant role in natural elemental geochemistry cycle and artificial water treatment processes. Therefore, further investigation into the role of dissolved Mn(III) in aquatic systems is warranted to unravel unexplored coupled elemental redox reaction processes mediated by dissolved Mn(III), filling in the gaps in our understanding of manganese environmental geochemistry, and providing a theoretical basis for recognizing the role of dMn(III) role in water treatment technologies.
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Affiliation(s)
- Xingxing Wang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Matthew R Jones
- Wolfson Atmospheric Chemistry Laboratory, University of York, York YO10 5DD, United Kingdom
| | - Zezhen Pan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China; National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Shanghai 200438, China
| | - Xiaohan Lu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Yamin Deng
- Key Laboratory of Groundwater Quality and Health (China University of Geosciences), Ministry of Education, Wuhan 430078, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution & School of Environmental Studies, China University of, Geosciences, Wuhan 430078, China
| | - Mengqiang Zhu
- Department of Geology, University of Maryland, College Park, MD, 20740, USA
| | - Zimeng Wang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China; National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary, Shanghai 200438, China; Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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4
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Li C, Chen R, Ouyang W, Xue C, Liu M, Liu H. The response of C/N/S cycling functional microbial communities to redox conditions in shallow aquifers using in-situ sediment as bio-trap matrix. ENVIRONMENTAL TECHNOLOGY 2024; 45:3666-3678. [PMID: 37323025 DOI: 10.1080/09593330.2023.2225704] [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: 12/03/2022] [Accepted: 05/20/2023] [Indexed: 06/17/2023]
Abstract
Microbial communities are fundamental components driving critical biogeochemical carbon (C), nitrogen (N) and sulfur (S) cycles in groundwater ecosystems. The reduction-oxidation (redox) potential is one important environmental factor influencing the microbial community composition. Here, we developed a bio-trap method using in-situ sediment as a matrix to collect aquifer sediment samples and evaluate the response of microbial composition and C/N/S cycling functions to redox variations created by providing sole O2, joint O2 and H2, and sole H2 to three wells. Illumina sequencing analyses showed that the microbial communities in the bio-trap sediment could respond quickly to redox changes in the wells, demonstrating that this bio-trap method is promising for detecting microbial variation in the aquifer sediment. The microbial metabolic functions related to C, N and S cyclings and organic pollutants degradation were predicted by the Kyoto Encyclopedia of Genes and Genomes (KEGG) approach. It was found that the joint O2 and H2 injection produced medium oxidation-reduction potential (ORP -346 and -614 mV) and enhanced more microbial functions than sole O2 or H2, which mainly include oxidative phosphorylation, most carbon source metabolism, various pollutants degradation, and nitrogen and sulfur metabolism. Moreover, the functional genes encoding phenol monooxygenase, dioxygenase, nitrogen fixation, nitrification, aerobic and anaerobic nitrate reductase, nitrite reductase, nitric oxide reductase, and sulfur oxidation increased. These findings tell us the contaminant bioremediation and N, S metabolism can be promoted by adjusting ORP realised by injecting joint O2 and H2.
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Affiliation(s)
- Cui Li
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, People's Republic of China
- Hubei Ecology Polytechnic College, Wuhan, People's Republic of China
| | - Rong Chen
- School of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan, People's Republic of China
| | - Weiwei Ouyang
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, People's Republic of China
| | - Chen Xue
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, People's Republic of China
| | - Minghui Liu
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, People's Republic of China
| | - Hui Liu
- Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan, People's Republic of China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, People's Republic of China
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5
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Sultana R, Johnson RH, Tigar AD, Wahl TJ, Meurer CE, Hoss KN, Xu S, Paradis CJ. Contaminant mobilization from the vadose zone to groundwater during experimental river flooding events. JOURNAL OF CONTAMINANT HYDROLOGY 2024; 265:104391. [PMID: 38936239 DOI: 10.1016/j.jconhyd.2024.104391] [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: 04/19/2024] [Revised: 06/08/2024] [Accepted: 06/22/2024] [Indexed: 06/29/2024]
Abstract
Natural river flooding events can mobilize contaminants from the vadose zone and lead to increased concentrations in groundwater. Characterizing the mass and transport mechanisms of contaminants released from the vadose zone to groundwater during these recharge events is particularly challenging. Therefore, conducting highly-controlled in-situ experiments that simulate natural flooding events can help increase the knowledge of where contaminants can be stored and how they can move between hydrological compartments. This study specifically targets uranium pollution, which is accompanied by high sulfate levels in the vadose zone and groundwater. Two novel experimental river flooding events were conducted that utilized added non-reactive halides (bromide and iodide) and 2,6-difluorobenzoate tracers. In both experiments, about 8 m3 of traced water from a nearby contaminant-poor river was flooded in a 3-m diameter basin and infiltrated through the vadose zone and into a contaminant-rich unconfined aquifer for an average of 10 days. The aquifer contained 13 temporary wells that were monitored for solute concentration for up to 40 days. The groundwater analysis was conducted for changes in contaminant mass using the Theissen polygon method and for transport mechanisms using temporal moments. The results indicated an increase in uranium (21 and 24%), and sulfate (24 and 25%) contaminant mass transport to groundwater from the vadose zone during both experiments. These findings confirmed that the vadose zone can store and release substantial amounts of contaminants to groundwater during flooding events. Additionally, contaminants were detected earlier than the added tracers, along with higher concentrations. These results suggested that contaminant-rich pore water in the vadose zone was transported ahead of the traced flood waters and into groundwater. During the first flooding event, elevated concentrations of contaminants were sustained, and that chloride behaved similarly. The findings implied that contaminant- and chloride-rich evaporites in the vadose zone were dissolved during the first flooding event. For the second flooding event, the data suggested that the contaminant-rich evaporites continued to dissolve whereas chloride-rich evaporites were previously flushed. Overall, these findings indicated that contaminant-rich pore water and evaporites in the vadose zone can play a significant role in contaminant transport during flooding events.
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Affiliation(s)
- Rakiba Sultana
- Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211, United States.
| | - Raymond H Johnson
- RSI EnTech, LLC, Contractor to the U.S. Department of Energy Office of Legacy Management, 2597 Legacy Way, Grand Junction, CO 81503, United States
| | - Aaron D Tigar
- RSI EnTech, LLC, Contractor to the U.S. Department of Energy Office of Legacy Management, 2597 Legacy Way, Grand Junction, CO 81503, United States
| | - Timothy J Wahl
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave, Milwaukee, WI 53204, United States
| | - Cullen E Meurer
- Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211, United States
| | - Kendyl N Hoss
- Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211, United States
| | - Shangping Xu
- Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211, United States
| | - Charles J Paradis
- Department of Geosciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Ave, Milwaukee, WI 53211, United States
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6
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Spielman-Sun E, Boye K, Dwivedi D, Engel M, Thompson A, Kumar N, Noël V. A Critical Look at Colloid Generation, Stability, and Transport in Redox-Dynamic Environments: Challenges and Perspectives. ACS EARTH & SPACE CHEMISTRY 2024; 8:630-653. [PMID: 38654896 PMCID: PMC11033945 DOI: 10.1021/acsearthspacechem.3c00255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/20/2024] [Accepted: 02/07/2024] [Indexed: 04/26/2024]
Abstract
Colloid generation, stability, and transport are important processes that can significantly influence the fate and transport of nutrients and contaminants in environmental systems. Here, we critically review the existing literature on colloids in redox-dynamic environments and summarize the current state of knowledge regarding the mechanisms of colloid generation and the chemical controls over colloidal behavior in such environments. We also identify critical gaps, such as the lack of universally accepted cross-discipline definition and modeling infrastructure that hamper an in-depth understanding of colloid generation, behavior, and transport potential. We propose to go beyond a size-based operational definition of colloids and consider the functional differences between colloids and dissolved species. We argue that to predict colloidal transport in redox-dynamic environments, more empirical data are needed to parametrize and validate models. We propose that colloids are critical components of element budgets in redox-dynamic systems and must urgently be considered in field as well as lab experiments and reactive transport models. We intend to bring further clarity and openness in reporting colloidal measurements and fate to improve consistency. Additionally, we suggest a methodological toolbox for examining impacts of redox dynamics on colloids in field and lab experiments.
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Affiliation(s)
- Eleanor Spielman-Sun
- Environmental
Geochemistry Group at SLAC, Stanford Synchrotron Radiation Lightsource
(SSRL), SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Kristin Boye
- Environmental
Geochemistry Group at SLAC, Stanford Synchrotron Radiation Lightsource
(SSRL), SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Dipankar Dwivedi
- Earth
and Environmental Sciences Area, Lawrence
Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Maya Engel
- Department
of Soil and Water Sciences, Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Aaron Thompson
- Department
of Crop and Soil Sciences, University of
Georgia, Athens, Georgia 30602, United States
| | - Naresh Kumar
- Soil
Chemistry, Wageningen University and Research, Wageningen 6708 PB, The Netherlands
| | - Vincent Noël
- Environmental
Geochemistry Group at SLAC, Stanford Synchrotron Radiation Lightsource
(SSRL), SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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7
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Li C, Zhang Y, Zheng Y, Shi C, Lu Y, Zhang Y, Yuan S. Contaminant transformation during sediment oxygenation: Temporal variation of oxidation mechanisms mediated by hydroxyl radicals and aerobic microbes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170855. [PMID: 38340822 DOI: 10.1016/j.scitotenv.2024.170855] [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: 12/04/2023] [Revised: 01/29/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024]
Abstract
Sediment oxidation by oxygen is ubiquitous, whereas the mechanisms of concurrent contaminant oxidation, particularly the temporal variation of chemical and biological oxidation, remain inadequately understood. This study investigated the oxidation of two contaminants (phenol and trichloroethylene) with different responses during the oxygenation of four natural sediments with different redox properties. Results showed that contaminant oxidation was initially dominated by hydroxyl radicals (•OH) (first stage), stabilized for different time for different sediments (second stage), and was re-started by microbial mechanism (third stage). In the first short stage, the contribution of chemical oxidation by •OH was mainly determined by the variation of sediment electron-donating capacity (EDC). In the second long stage, the stabilization time was dependent on sediment redox properties, that is, the abundance and growth of aerobic microbes capable of degrading the target contaminants. A more reduced sediment resulted in a higher extent of oxidation by •OH and a longer stabilization time. When the third stage of aerobic microbial oxidation was started, the contaminants like phenol that can be utilized by microbes can be oxidized quickly and completely, and those refractory contaminants like trichloroethylene remained unchanged. The study differentiates chemical and biological mechanisms for contaminant oxidation during sediment oxygenation.
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Affiliation(s)
- Chengwei Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Yanting Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Yunsong Zheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Chongwen Shi
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Yuxi Lu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Yaoqiang Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China.
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8
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Kent RD, Johnson RH, Laase AD, Nyman JL. Modeling evaluation of the impact of residual source material on remedial time frame at a former uranium mill site. JOURNAL OF CONTAMINANT HYDROLOGY 2024; 261:104298. [PMID: 38242064 DOI: 10.1016/j.jconhyd.2024.104298] [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: 09/18/2023] [Revised: 12/14/2023] [Accepted: 01/09/2024] [Indexed: 01/21/2024]
Abstract
Groundwater contamination at legacy uranium processing sites is an ongoing global challenge. Plumes at many uranium-contaminated sites are more persistent than originally predicted by groundwater modeling. Previous investigations of uranium plume persistence identified residual and secondary sources that contribute to plume longevity, but there is a remaining need to revise forecasted cleanup times using information about these ongoing sources. The purpose of this study is to investigate the quantitative impact of residual vadose zone sources of uranium on groundwater remediation time frame. This objective was approached by applying numerical uranium transport simulations and uncertainty analysis to a former uranium mill site in the southwestern United States. Information from recent site investigations provided details about the distribution and release characteristics of uranium accumulations in the vadose zone. The residual uranium characteristics were incorporated as decaying source terms in the transport model. A stochastic approach using an iterative ensemble smoother was applied for history matching, and the transport model was used to assess the impact of multiple remedial alternatives on forecasted time frame. The forecasted time frame to achieve the groundwater remediation goal for uranium by monitored natural attenuation is on the order of thousands of years, and treatment of the dissolved plume does not reduce the projected time frame. The large proportion of residual uranium mass remaining in the vadose zone and the gradual leaching rate due to the site's semiarid climate create a long-lived source that can sustain a dissolved plume for thousands of years despite an estimated 99% mass removal achieved during mill tailings disposal. Residual uranium in vadose zone sediments beneath former tailings impoundments could present comparable uranium plume persistence and remediation challenges at other legacy uranium mill sites in semiarid climates. Other remaining uranium-impacted sites are similarly complex, and forecasted remedial time frames are needed to effectively achieve compliance, manage risk, assess the benefits of additional treatment, manage and project costs, and support beneficial site reuse.
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Affiliation(s)
- Ronald D Kent
- RSI EnTech, LLC, U.S. Department of Energy Office of Legacy Management Support, Grand Junction, CO, USA.
| | - Raymond H Johnson
- RSI EnTech, LLC, U.S. Department of Energy Office of Legacy Management Support, Grand Junction, CO, USA
| | - Alan D Laase
- RSI EnTech, LLC, U.S. Department of Energy Office of Legacy Management Support, Grand Junction, CO, USA
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9
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Gao H, Yang L, Song X, Guo M, Li B, Cui X. Sources and hydrogeochemical processes of groundwater under multiple water source recharge condition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166660. [PMID: 37657547 DOI: 10.1016/j.scitotenv.2023.166660] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/26/2023] [Accepted: 08/26/2023] [Indexed: 09/03/2023]
Abstract
Ecological water replenishment (EWR) is an essential approach for improving the quantity and quality of regional water. The Chaobai River is a major river in Beijing that is replenished with water from multiple sources, including reclaimed water (RW), the South-North Water Transfer Project (SNTP), reservoir discharge (RD). The effects of multiple water source recharge (MWSR) on groundwater quality remain unclear. In this study, hydrochemical ions, isotopes (δ2H-H2O, δ18O-H2O, δ15N-NO3-, and δ18O-NO3-), mixing stable isotope analysis in R (MixSIAR), and hydrogeochemical modeling were used to quantify the contributions and impacts of different water sources on groundwater and to propose a conceptual model. The results showed that during the period before reservoir discharge, RW and SNTP accounted for 38 %-41 % and 54 % of the groundwater in their corresponding recharge areas, respectively. The groundwater in the RW recharge area contained high levels of Na+ and Cl- leading to the precipitation of halite, and was the main factor for the spatial variation in groundwater hydrochemical components. The surface water changed from Na·K - Cl·SO4 type to Ca·Mg - HCO3 type which was similar to groundwater after reservoir discharge. RD accounted for 30 % of the groundwater; however, it did not change the hydrochemical type of groundwater. Dual nitrate stable isotopes and MixSIAR demonstrated that RW was the primary source of NO3- in groundwater, contributing up to 76-89 %, and reservoir discharge effectively reduced the contribution of RW. δ15N-NO3- or δ18O-NO3- in relation to NO3-N suggests that denitrification is the main biogeochemical process of nitrogen in groundwater, whereas water recharge from the SNTP and RD reduces denitrification and dilutes NO3-. This study provides insights into the impact of anthropogenically controlled ecological water replenishment from different water sources on groundwater and guides the reasonable allocation of water resources.
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Affiliation(s)
- Heng Gao
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lihu Yang
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xianfang Song
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Minli Guo
- Beijing Water Science and Technology Institute, Beijing Engineering Technique Research Center for Exploration and Utilization of Non-Conventional Water Resources and Water Use Efficiency, Beijing 100048, China
| | - Binghua Li
- Beijing Water Science and Technology Institute, Beijing Engineering Technique Research Center for Exploration and Utilization of Non-Conventional Water Resources and Water Use Efficiency, Beijing 100048, China
| | - Xu Cui
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
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10
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Lacroix EM, Aeppli M, Boye K, Brodie E, Fendorf S, Keiluweit M, Naughton HR, Noël V, Sihi D. Consider the Anoxic Microsite: Acknowledging and Appreciating Spatiotemporal Redox Heterogeneity in Soils and Sediments. ACS EARTH & SPACE CHEMISTRY 2023; 7:1592-1609. [PMID: 37753209 PMCID: PMC10519444 DOI: 10.1021/acsearthspacechem.3c00032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/07/2023] [Accepted: 07/21/2023] [Indexed: 09/28/2023]
Abstract
Reduction-oxidation (redox) reactions underlie essentially all biogeochemical cycles. Like most soil properties and processes, redox is spatiotemporally heterogeneous. However, unlike other soil features, redox heterogeneity has yet to be incorporated into mainstream conceptualizations of soil biogeochemistry. Anoxic microsites, the defining feature of redox heterogeneity in bulk oxic soils and sediments, are zones of oxygen depletion in otherwise oxic environments. In this review, we suggest that anoxic microsites represent a critical component of soil function and that appreciating anoxic microsites promises to advance our understanding of soil and sediment biogeochemistry. In sections 1 and 2, we define anoxic microsites and highlight their dynamic properties, specifically anoxic microsite distribution, redox gradient magnitude, and temporality. In section 3, we describe the influence of anoxic microsites on several key elemental cycles, organic carbon, nitrogen, iron, manganese, and sulfur. In section 4, we evaluate methods for identifying and characterizing anoxic microsites, and in section 5, we highlight past and current approaches to modeling anoxic microsites. Finally, in section 6, we suggest steps for incorporating anoxic microsites and redox heterogeneities more broadly into our understanding of soils and sediments.
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Affiliation(s)
- Emily M. Lacroix
- Institut
des Dynamiques de la Surface Terrestre (IDYST), Université de Lausanne, 1015 Lausanne, Switzerland
- Department
of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Meret Aeppli
- Institut
d’ingénierie de l’environnement (IIE), École Polytechnique Fédérale
de Lausanne, 1015 Lausanne, Switzerland
| | - Kristin Boye
- Environmental
Geochemistry Group, SLAC National Accelerator
Laboratory, Menlo Park, California 94025, United States
| | - Eoin Brodie
- Lawrence
Berkeley Laboratory, Earth and Environmental
Sciences Area, Berkeley, California 94720, United States
| | - Scott Fendorf
- Department
of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Marco Keiluweit
- Institut
des Dynamiques de la Surface Terrestre (IDYST), Université de Lausanne, 1015 Lausanne, Switzerland
| | - Hannah R. Naughton
- Lawrence
Berkeley Laboratory, Earth and Environmental
Sciences Area, Berkeley, California 94720, United States
| | - Vincent Noël
- Environmental
Geochemistry Group, SLAC National Accelerator
Laboratory, Menlo Park, California 94025, United States
| | - Debjani Sihi
- Department
of Environmental Sciences, Emory University, Atlanta, Georgia 30322, United States
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11
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Hu M. Spatiotemporal distribution and controlling factors on ammonium in waters in the central Yangtze River Basin, China. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 258:104239. [PMID: 37683374 DOI: 10.1016/j.jconhyd.2023.104239] [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: 04/07/2023] [Revised: 08/04/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
High levels of ammonium in water can compromise the ecological environment and be harmful to human beings. It is of great significance to understand the source and controlling factors of ammonium in waters. However, the distribution and controlling factors on ammonium in the central Yangtze River Basin have been rarely reported. The results showed that 6.58% of the surface water (SW) exceeded the China national guideline of category III for NH4+-N (i.e., 1.0 mg/L) and 30.19% of the groundwater (GW) exceeded the China national guideline of category III for NH4+-N (i.e., 0.5 mg/L). Notably, the ammonium concentrations of the plain area in the middle were much higher, which reached to the highest value at the junction of the Yangtze River and Dongting Lake. Nitrogen in SW may originate from manure but more nitrogen sources in GW. The net anthropogenic nitrogen input (NANI) can provide enough organic nitrogen for the mineralization. NH4+-N in SW was more affected by fertilizer nitrogen and feed nitrogen input but more affected by agricultural nitrogen fixation in GW. Agricultural and industrial activities controlled NH4+-N in SW and GW by increasing nitrogen input and changing hydrological conditions. In general, this research exposed the controlling of different types of factors on ammonium in waters, providing a guidance for the water pollution prevention in study area.
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Affiliation(s)
- Meiyan Hu
- School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Eco-environment Technology R&D and Service Center, Wuhan University, Wuhan 430079, PR China.
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12
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Wang Y, Cao X, Yu H, Xu Y, Peng J, Qu J. Nitrate with enriched heavy oxygen isotope linked to changes in nitrogen source and transformation as groundwater table rises. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131527. [PMID: 37163892 DOI: 10.1016/j.jhazmat.2023.131527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/19/2023] [Accepted: 04/26/2023] [Indexed: 05/12/2023]
Abstract
Nitrate is a significant constituent of the total nitrogen pool in shallow aquifers and poses an escalating threat to groundwater resources, making it crucial to comprehend the source, conversion, and elimination of nitrogen using appropriate techniques. Although dual-isotope dynamics in nitrate have been widely used, uncertainties remain regarding the asynchronously temporal changes in δ18O-NO3- and δ15N-NO3- observed in hypoxic aquifers. This study aimed to investigate changes in nitrogen sources and transformations using temporal changes in field-based NO3- isotopic composition, hydro-chemical variables, and environmental DNA profiling, as the groundwater table varied. The results showed that the larger enrichment in δ18O-NO3- (+13‰) compared with δ15N-NO3- (-2‰) on average during groundwater table rise was due to a combination of factors, including high 18O-based atmospheric N deposition, canopies nitrification, and soil nitrification transported vertically by rainfalls, and 18O-enriched O2 produced through microbial and root respiration within denitrification. The strong association between functional gene abundance and nitrogen-related indicators suggests that anammox was actively processed with nitrification but in small bacterial population during groundwater table rise. Furthermore, bacterial species associated with nitrogen-associated gradients provided insight into subsurface nitrogen transformation, with Burkholderiaceae species and Pseudorhodobacter potentially serving as bioindicators of denitrification, while Candidatus Nitrotogn represents soil nitrification. Fluctuating groundwater tables can cause shifts in hydro-chemical and isotopic composition, which in turn can indicate changes in nitrogen sources and transformations. These changes can be used to improve input sources for mixture models and aid in microbial remediation of nitrate.
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Affiliation(s)
- Yajun Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaofeng Cao
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Hongwei Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yan Xu
- College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China
| | - Jianfeng Peng
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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13
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Gu C, Bai J, Zhang C, Bai Y. Nitrate sink function of riparian zones induced by river stage fluctuations. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 328:116985. [PMID: 36527799 DOI: 10.1016/j.jenvman.2022.116985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 11/19/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
River stage fluctuation (RSF) induced by tides, dam releases, or storms may lead to enhanced nitrogen cycling (N cycling) in riparian zones (RZ). We conducted a laboratory water table manipulation experiment and applied a multiphase flow and transport model (TOUGHREACT) to investigate the role of RSF in N cycling in the RZ. Coupled nitrification and denitrification occur in the water table fluctuation zone under alternating aerobic and anaerobic conditions. Nitrate removal was enhanced in the saturated and unsaturated zones of the RZ. The net nitrate reduction rate in groundwater increased with the increasing number of RSF, as a result, the cumulative water influx. The RZ nitrate sink function became stronger with increasing RSF amplitude and soil organic matter (SOM) content, and weaker with increasing [NH4+]/[NO3-] ratio and mineralization rate. RSF generally creates a hot moment for net nitrate removal in the RZ. However, a hot moment for the nitrate source function might occur if the [NH4+]/[NO3-] ratio of groundwater is much greater than 1 and/or if a large pool of nitrate accumulates in the topsoil over a prolonged dry period. The absence of oxygen diffusion in the model would overestimate the nitrate removal capacity of the RZ.
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Affiliation(s)
- Chuanhui Gu
- Environmental Research Center, Duke Kunshan University, Kunshan, 215316, China.
| | - Junhong Bai
- School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Chengdong Zhang
- School of Environment, Beijing Normal University, Beijing, 100875, China
| | - Yanchao Bai
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225009, China
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14
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Duan L, Fan J, Wang Y, Wu Y, Xie C, Ye F, Lv J, Mao M, Sun Y. Interaction mechanism between nitrogen conversion and the microbial community in the hydrodynamic heterogeneous interaction zone. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:5799-5814. [PMID: 35980525 DOI: 10.1007/s11356-022-22549-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
To study the inorganic nitrogen in the process of interaction of river and groundwater and the changes in the microbial community, a vertical simulation device was used to simulate groundwater recharge to river water (upwelling) and river water recharge to groundwater (downwelling). The inorganic nitrogen concentrations in the soil and water solution as well as the characteristics of the microbial community were assessed to determine the inorganic nitrogen transformation and microbial community response in the heterogeneous interaction zone under hydrodynamic action, and the interaction mechanism between nitrogen transformation and the microbial community in the interaction zone was revealed. The removal rates of NO3--N in the simulated solution reached 99.1% and 99.3% under the two fluid-groundwater conversion modes, and the prolonged hydraulic retention time (HRT) of the oxidization-reduction layer in the fine clay area and the high organic matter content made the inorganic nitrogen transformation process dominated by microorganisms more complete. The denitrification during upwelling, dominated by denitrifying bacteria in Sphingomonas, Pseudomonas, Bacillus, and Arthrobacter, was stronger than that during downwelling. Dissimilatory nitrate reduction to ammonium (DNRA), controlled by some aerobic bacteria in Pseudomonas, Bacillus, and Desulfovibrio, was more intense in downflow mode than upflow mode.
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Affiliation(s)
- Lei Duan
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Jinghui Fan
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Yike Wang
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Yakun Wu
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Chenchen Xie
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Fei Ye
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Jiajia Lv
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Ming Mao
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China
| | - Yaqiao Sun
- School of Hydraulic Engineering and Environment, Chang'an University, Xi'an, 710061, China.
- Key Laboratory of Underground Hydrology and Ecological Effects in Arid Regions, Ministry of Education, Xi'an, 710064, China.
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15
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Wang X, Liu X, Wang L, Yang J, Wan X, Liang T. A holistic assessment of spatiotemporal variation, driving factors, and risks influencing river water quality in the northeastern Qinghai-Tibet Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:157942. [PMID: 35995155 DOI: 10.1016/j.scitotenv.2022.157942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/02/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
The Qinghai-Tibet Plateau (QTP) is the source for many of the most important rivers in Asia. It is also an essential ecological barrier in China and has the characteristic of regional water conservation. Given this importance, we analyzed the spatiotemporal distribution patterns and trends of 10 water quality parameters. These measurements were taken monthly from 67 monitoring stations in the northeastern QTP from 2015 to 2019. To evaluate water quality trends, major factors influencing water quality, and water quality risks, we used a series of analytical approaches including Mann-Kendall test, Boruta algorithm, and interval fuzzy number-based set-pair analysis (IFN-SPA). The results revealed that almost all water monitoring stations in the northeastern QTP were alkaline. From 2015 to 2019, the water temperature and dissolved oxygen of most monitoring stations were significantly reduced. Chemical oxygen demand, permanganate index, five-day biochemical oxygen demand, total phosphorus, and fluoride all showed a downward trend across this same time frame. The annual average total nitrogen (TN) concentration fluctuation did not significantly decrease across the measured time frame. Water quality index (WQI-DET) indicated bad or poor water quality in the study area; however, water quality index without TN (WQI-DET') reversed the water quality value. The difference between the two indexes suggested that TN was a significant parameter affecting river water quality in the northeastern QTP. Both Spearman correlation and Boruta algorithm show that elevation, urban land, cropland, temperature, and precipitation influence the overall water quality status in the northeastern QTP. The results showed that between 2015 and 2019, most rivers monitored had a relatively low risk of degradation in water quality. This study provides a new perspective on river water quality management, pollutant control, and risk assessment in an area like the QTP that has sensitive and fragile ecology.
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Affiliation(s)
- Xueping Wang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojie Liu
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Lingqing Wang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jun Yang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoming Wan
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Tao Liang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
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16
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Kinsela AS, Payne TE, Bligh MW, Vázquez-Campos X, Wilkins MR, Comarmond MJ, Rowling B, Waite TD. Contaminant release, mixing and microbial fluctuations initiated by infiltrating water within a replica field-scale legacy radioactive waste trench. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158241. [PMID: 36007652 DOI: 10.1016/j.scitotenv.2022.158241] [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: 05/02/2022] [Revised: 08/14/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Numerous legacy near-surface radioactive waste sites dating from the mid 20th century have yet to be remediated and present a global contamination concern. Typically, there is insufficient understanding of contaminant release and redistribution, with invasive investigations often impractical due to the risk of disturbing the often significantly radiotoxic contaminants. Consequently, a replica waste trench (~5.4 m3), constructed adjacent to a legacy radioactive waste site (Little Forest Legacy Site, LFLS), was used to assist our understanding of the release and mixing processes of neodymium (Nd) - a chemical analogue for plutonium(III) and americium(III), two significant radionuclides in many contaminated environments. In order to clarify the behaviour of contaminants released from buried objects such as waste containers, a steel drum, representative of the hundreds of buried drums within the LFLS, was placed within the trench. Dissolved neodymium nitrate was introduced as a point-source contaminant to the base of the trench, outside the steel drum. Hydrologic conditions were manipulated to simulate natural rainfall intensities with dissolved lithium bromide added as a tracer. Neodymium was primarily retained both at its point of release at the bottom of the trench (>97 %) as well as at a steel container corrosion point, simulated through the emplacement of steel wool. However, over the 8-month field experiment, advective mixing initiated by surface water intrusions rapidly redistributed a small proportion of Nd to shallower waters (~1.5-1.7 %), as well as throughout the buried steel drum. Suspended particulate forms of Nd (>0.2 μm) were measured at all depths in the suboxic trench and were persistent across the entire study. Analyses of the microbial communities showed that their relative abundances and metabolic functions were strongly influenced by the prevailing geochemical conditions as a result of fluctuating water depths associated with rainfall events. The site representing steel corrosion exhibited divergent biogeochemical results with anomalous changes (sharp decrease) observed in both dissolved contaminant concentration as well as microbial diversity and functionality. This research demonstrates that experimental trenches provide a safe and unique method for simulating the behaviour of subsurface radioactive contaminants with results demonstrating the initial retention, partial shallow water redistribution, and stability of particulate form(s) of this radioactive analogue. These results have relevance for appropriate management and remediation strategies for the adjacent legacy site as well as for similar sites across the globe.
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Affiliation(s)
- Andrew S Kinsela
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia
| | - Timothy E Payne
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Mark W Bligh
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia
| | - Xabier Vázquez-Campos
- NSW Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - Marc R Wilkins
- NSW Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - M Josick Comarmond
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Brett Rowling
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - T David Waite
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia.
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17
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Wu Y, Xu L, Wang Z, Cheng J, Lu J, You H, Zhang X. Microbially mediated Fe-N coupled cycling at different hydrological regimes in riparian wetland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158237. [PMID: 36007641 DOI: 10.1016/j.scitotenv.2022.158237] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/09/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Although the significance of the coupled Fe- and N- cycling processes on biogeochemical transformation in riparian wetlands is well-known, the regulation associated with the changes on the microbiotas during different hydrological regimes remains unclear. This study performed field investigations on the bacterial community compositions (BCC) and specific genera associated to Fe- and N- cycling in the rhizosphere soil and sediments in a riparian wetland in Poyang lake, China. The predominant phyla Proteobacteria, Acidobacteria, and Nitrospirae from all the samples remarkably decreased after long-term continuous flooding, while Actinobacteria, Firmicutes and Bacteroidetes were enriched. For the family level, the relative abundances of iron-oxidizing bacteria (FeOB) Gallionellaceae, and N fixing bacteria Nitrospiraceae and Bradyrhizobiaceae significantly declined upon the long-term flooding and then increased with dewatering, which were consistent with the functional genes sequencing analysis. In which, the Bradyrhizobiaceae (RA 2.0 %-34.6 %) was the dominant nirS denitrifier and potential iron-reducing bacteria (FeRB), Sideroxydans lithotrophicus was one of the dominant FeOB (RA 1.7 %-23 %), which was also identified to be the nirS dentrifier (RA 0.2 %-4.3 %). The absolute quantification of the functional genes levels including nirS, nirK, FeRB (Geobacter spp.) showed their significant increases by 3-7 times upon desiccation compared to that under post-CF. The PCA and RDA results indicated the linkage between redox changes of N and Fe during inundation mediated by FeRB, NOB, and FeOB, which were closely related to hydrochemical indices NO3-, Fe2+ and SO42-. These evidences all implied the likely occurrence of nitrate reduction coupled to Fe(II) oxidation (NRFeOx) under oligotrophic conditions, which was potentially facilitated by metabolizers consisting of highly correlated Bradyrhizobiaceae and Sideroxydans (rho = 0.86, p < 0.01). These findings provide an interpretation of the biological reactions in the microbially mediated NRFeOx processes driven by hydrological change, which could assist the mechanistic understanding of the global biogeochemical cycles of iron and nitrogen in riparian wetlands.
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Affiliation(s)
- Yuexia Wu
- School of Business Administration, Nanjing University of Finance & Economics, Nanjing 210023, PR China; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Ligang Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China.
| | - Zhenglu Wang
- College of Oceanography, Hohai University, Nanjing, Jiangsu 210098, PR China
| | - Junxiang Cheng
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Jilai Lu
- College of Food Science & Engineering, Nanjing University of Finance & Economics, Nanjing 210023, PR China
| | - Hailin You
- Institute of Watershed Ecology, Jiangxi Academy of Sciences, Nanchang, Jiangxi 330096, PR China
| | - Xiaodong Zhang
- School of Business Administration, Nanjing University of Finance & Economics, Nanjing 210023, PR China
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18
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Occurrence Characteristics of Inorganic Nitrogen in Groundwater in Silty-Clay Riparian Hyporheic Zones under Tidal Action: A Case Study of the Jingzi River in Shanghai, China. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12157704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
For comprehending the effect of tidal action on nitrogen cycle in silty-clay riparian hyporheic zones, the synchronous monitoring of water level and water quality was carried out along a test transect during a spring tidal period from 21 to 23 October 2021. Moreover, the permeability and chemical composition of soil samples from drilled holes were measured. Subsequently, the spatiotemporal variation of inorganic nitrogen concentrations in the groundwater in the riparian hyporheic zone was investigated during the study period, and the potential reason was discussed. It is shown that the delayed response time of groundwater level in the silty-clay riparian zone to the tide-driven fluctuation of the river stage increased with distance from the shore and reached 3.0 h at the position 3.83 m away from the shore. The continuous infiltration of the river water under tide action contributed to the aerobic and neutral riparian hyporheic zone conductive to nitrification. Within 4 m away from the bank, the dominant inorganic nitrogen form changed from -N to -N, upon increasing the distance from the bank. Additionally, the removal of nitrogen could occur in the riparian hyporheic zone with aerobic and neutral environment under the conjoint control of nitrification, microbial assimilation, and aerobic denitrification.
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19
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Soils and sediments host Thermoplasmata archaea encoding novel copper membrane monooxygenases (CuMMOs). THE ISME JOURNAL 2022; 16:1348-1362. [PMID: 34987183 PMCID: PMC9038741 DOI: 10.1038/s41396-021-01177-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 12/02/2021] [Accepted: 12/10/2021] [Indexed: 01/22/2023]
Abstract
Copper membrane monooxygenases (CuMMOs) play critical roles in the global carbon and nitrogen cycles. Organisms harboring these enzymes perform the first, and rate limiting, step in aerobic oxidation of ammonia, methane, or other simple hydrocarbons. Within archaea, only organisms in the order Nitrososphaerales (Thaumarchaeota) encode CuMMOs, which function exclusively as ammonia monooxygenases. From grassland and hillslope soils and aquifer sediments, we identified 20 genomes from distinct archaeal species encoding divergent CuMMO sequences. These archaea are phylogenetically clustered in a previously unnamed Thermoplasmatota order, herein named the Ca. Angelarchaeales. The CuMMO proteins in Ca. Angelarchaeales are more similar in structure to those in Nitrososphaerales than those of bacteria, and contain all functional residues required for general monooxygenase activity. Ca. Angelarchaeales genomes are significantly enriched in blue copper proteins (BCPs) relative to sibling lineages, including plastocyanin-like electron carriers and divergent nitrite reductase-like (nirK) 2-domain cupredoxin proteins co-located with electron transport machinery. Ca. Angelarchaeales also encode significant capacity for peptide/amino acid uptake and degradation and share numerous electron transport mechanisms with the Nitrososphaerales. Ca. Angelarchaeales are detected at high relative abundance in some of the environments where their genomes originated from. While the exact substrate specificities of the novel CuMMOs identified here have yet to be determined, activity on ammonia is possible given their metabolic and ecological context. The identification of an archaeal CuMMO outside of the Nitrososphaerales significantly expands the known diversity of CuMMO enzymes in archaea and suggests previously unaccounted organisms contribute to critical global nitrogen and/or carbon cycling functions.
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20
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Arora-Williams K, Holder C, Secor M, Ellis H, Xia M, Gnanadesikan A, Preheim SP. Abundant and persistent sulfur-oxidizing microbial populations are responsive to hypoxia in the Chesapeake Bay. Environ Microbiol 2022; 24:2315-2332. [PMID: 35304940 PMCID: PMC9310604 DOI: 10.1111/1462-2920.15976] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 03/07/2022] [Accepted: 03/12/2022] [Indexed: 01/04/2023]
Abstract
The number, size and severity of aquatic low‐oxygen dead zones are increasing worldwide. Microbial processes in low‐oxygen environments have important ecosystem‐level consequences, such as denitrification, greenhouse gas production and acidification. To identify key microbial processes occurring in low‐oxygen bottom waters of the Chesapeake Bay, we sequenced both 16S rRNA genes and shotgun metagenomic libraries to determine the identity, functional potential and spatiotemporal distribution of microbial populations in the water column. Unsupervised clustering algorithms grouped samples into three clusters using water chemistry or microbial communities, with extensive overlap of cluster composition between methods. Clusters were strongly differentiated by temperature, salinity and oxygen. Sulfur‐oxidizing microorganisms were found to be enriched in the low‐oxygen bottom water and predictive of hypoxic conditions. Metagenome‐assembled genomes demonstrate that some of these sulfur‐oxidizing populations are capable of partial denitrification and transcriptionally active in a prior study. These results suggest that microorganisms capable of oxidizing reduced sulfur compounds are a previously unidentified microbial indicator of low oxygen in the Chesapeake Bay and reveal ties between the sulfur, nitrogen and oxygen cycles that could be important to capture when predicting the ecosystem response to remediation efforts or climate change.
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Affiliation(s)
- Keith Arora-Williams
- Department of Environmental Health and Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Christopher Holder
- Department of Earth and Planetary Sciences, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Maeve Secor
- Department of Environmental Health and Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Hugh Ellis
- Department of Environmental Health and Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Meng Xia
- Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA
| | - Anand Gnanadesikan
- Department of Earth and Planetary Sciences, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Sarah P Preheim
- Department of Environmental Health and Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
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21
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Aeppli M, Babey T, Engel M, Lacroix EM, Tolar BB, Fendorf S, Bargar JR, Boye K. Export of Organic Carbon from Reduced Fine-Grained Zones Governs Biogeochemical Reactivity in a Simulated Aquifer. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:2738-2746. [PMID: 35072465 DOI: 10.1021/acs.est.1c04664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sediment interfaces in alluvial aquifers have a disproportionately large influence on biogeochemical activity and, therefore, on groundwater quality. Previous work showed that exports from fine-grained, organic-rich zones sustain reducing conditions in downstream coarse-grained aquifers beyond the influence of reduced aqueous products alone. Here, we show that sustained anaerobic activity can be attributed to the export of organic carbon, including live microorganisms, from fine-grained zones. We used a dual-domain column system with ferrihydrite-coated sand and embedded reduced, fine-grained lenses from Slate River (Crested Butte, CO) and Wind River (Riverton, WY) floodplains. After 50 d of groundwater flow, 8.8 ± 0.7% and 14.8 ± 3.1% of the total organic carbon exported from the Slate and Wind River lenses, respectively, had accumulated in the sand downstream. Furthermore, higher concentrations of dissolved Fe(II) and lower concentrations of dissolved organic carbon in the sand compared to total aqueous transport from the lenses suggest that Fe(II) was produced in situ by microbial oxidation of organic carbon coupled to iron reduction. This was further supported by an elevated abundance of 16S rRNA and iron-reducing (gltA) gene copies. These findings suggest that organic carbon transport across interfaces contributes to downstream biogeochemical reactions in natural alluvial aquifers.
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Affiliation(s)
- Meret Aeppli
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Tristan Babey
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Maya Engel
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
- Geochemistry and Biogeochemistry Group, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Emily M Lacroix
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Bradley B Tolar
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Scott Fendorf
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - John R Bargar
- Geochemistry and Biogeochemistry Group, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Kristin Boye
- Geochemistry and Biogeochemistry Group, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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22
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Bonetti G, Limpert KE, Brodersen KE, Trevathan-Tackett SM, Carnell PE, Macreadie PI. The combined effect of short-term hydrological and N-fertilization manipulation of wetlands on CO 2, CH 4, and N 2O emissions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118637. [PMID: 34875268 DOI: 10.1016/j.envpol.2021.118637] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/12/2021] [Accepted: 12/03/2021] [Indexed: 06/13/2023]
Abstract
Freshwater wetlands are natural sinks of carbon; yet, wetland conversion for agricultural uses can shift these carbon sinks into large sources of greenhouse gases. We know that the anthropogenic alteration of wetland hydrology and the broad use of N-fertilizers can modify biogeochemical cycling, however, the extent of their combined effect on greenhouse gases exchange still needs further research. Moreover, there has been recent interest in wetlands rehabilitation and preservation by improving natural water flow and by seeking alternative solutions to nutrient inputs. In a microcosm setting, we experimentally exposed soils to three inundation treatments (Inundated, Moist, Drained) and a nutrient treatment by adding high nitrogen load (300 kg ha-1) to simulate physical and chemical disturbances. After, we measured the depth microprofiles of N2O and O2 concentration and CO2 and CH4 emission rates to determine how hydrological alteration and nitrogen input affect carbon and nitrogen cycling processes in inland wetland soils. Compared to the Control soils, N-fertilizer increased CO2 emissions by 40% in Drained conditions and increased CH4 emissions in Inundated soils over 90%. N2O emissions from Moist and Inundated soils enriched with nitrogen increased by 17.4 and 18-fold, respectively. Overall, the combination of physical and chemical disturbances increased the Global Warming Potential (GWP) by 7.5-fold. The first response of hydrological rehabilitation, while typically valuable for CO2 emission reduction, amplified CH4 and N2O emissions when combined with high nitrogen inputs. Therefore, this research highlights the importance of evaluating the potential interactive effects of various disturbances on biogeochemical processes when devising rehabilitation plans to rehabilitate degraded wetlands.
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Affiliation(s)
- Giuditta Bonetti
- Deakin University, Centre for Integrative Ecology, School of Life and Environmental Sciences, Burwood Campus, Victoria, 3125, Australia.
| | - Katy E Limpert
- Deakin University, Centre for Integrative Ecology, School of Life and Environmental Sciences, Burwood Campus, Victoria, 3125, Australia.
| | - Kasper Elgetti Brodersen
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark.
| | - Stacey M Trevathan-Tackett
- Deakin University, Centre for Integrative Ecology, School of Life and Environmental Sciences, Burwood Campus, Victoria, 3125, Australia.
| | - Paul E Carnell
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Queenscliff Campus, Queenscliff, Victoria, 3225, Australia.
| | - Peter I Macreadie
- Deakin University, Centre for Integrative Ecology, School of Life and Environmental Sciences, Burwood Campus, Victoria, 3125, Australia.
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23
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Zhu W, Yang J, Yao R, Wang X, Xie W, Li P. Nitrate leaching and NH 3 volatilization during soil reclamation in the Yellow River Delta, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117330. [PMID: 33991736 DOI: 10.1016/j.envpol.2021.117330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/02/2021] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
The agricultural ecological system is an important part of the Yellow River Delta (YRD); however, soil reclamation may trigger environmental concerns about nitrate leaching and NH3 volatilization in this area. To assess nitrogen losses during soil reclamation, a two-year field experiment was conducted with plastic film mulch, which is an effective way to alleviate water-salt stress. The Hydrus-2D software package was used to calculate nitrogen transport, transformation and losses. The results showed that nitrogen (N) retention in the soil varied during the two growing seasons, because soil water, salinity and climatic conditions acted together on nitrogen transport and transformation. Soil salinity promoted NH3 volatilization, and the proportions of ammonia volatilization were 22.78 percent and 19.50 percent of the N input in 2018 and 2019, respectively, because urea hydrolysis, nitrification and soil NH4+-N adsorption capacity were limited by soil salt. NO3--N leaching was controlled by soil water infiltration, climatic conditions and groundwater level. NO3--N leaching was 43.84 percent and 32.89 percent of the nitrogen input in 2018 and 2019, respectively; the difference was mainly caused by the different distribution of rainfall during the growing season; thus, soil water infiltration increased under heavy rainfall because it broke the barrier formed by the plough pan. This study indicates that there is a risk of nitrogen pollution during soil reclamation. In addition, Hydrus-2D has considerable potential to calculate nitrogen losses under the effect of plastic film mulch in this area.
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Affiliation(s)
- Wei Zhu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jingsong Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Rongjiang Yao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xiangping Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Wenping Xie
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Peiguang Li
- Yellow River Delta Ecological Research Station of Coastal Wetlands, Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China
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24
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Kinsela AS, Bligh MW, Vázquez-Campos X, Sun Y, Wilkins MR, Comarmond MJ, Rowling B, Payne TE, Waite TD. Biogeochemical Mobility of Contaminants from a Replica Radioactive Waste Trench in Response to Rainfall-Induced Redox Oscillations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8793-8805. [PMID: 34110792 DOI: 10.1021/acs.est.1c01604] [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: 06/12/2023]
Abstract
Results of investigations into factors influencing contaminant mobility in a replica trench located adjacent to a legacy radioactive waste site are presented in this study. The trench was filled with nonhazardous iron- and organic matter (OM)-rich components, as well as three contaminant analogues strontium, cesium, and neodymium to examine contaminant behavior. Imposed redox/water-level oscillations, where oxygen-laden rainwater was added to the anoxic trench, resulted in marked biogeochemical changes including the removal of aqueous Fe(II) and circulation of dissolved carbon, along with shifts to microbial communities involved in cycling iron (Gallionella, Sideroxydans) and methane generation (Methylomonas, Methylococcaceae). Contaminant mobility depended upon element speciation and rainfall event intensity. Strontium remained mobile, being readily translocated under hydrological perturbations. Strong ion-exchange reactions and structural incorporation into double-layer clay minerals were likely responsible for greater retention of Cs, which, along with Sr, was unaffected by redox oscillations. Neodymium was initially immobilized within the anoxic trenches, due to either secondary mineral (phosphate) precipitation or via the chemisorption of organic- and carbonate-Nd complexes onto variably charged solid phases. Oxic rainwater intrusions altered Nd mobility via competing effects. Oxidation of Fe(II) led to partial retention of Nd within highly sorbing Fe(III)/OM phases, whereas pH decreases associated with rainwater influxes resulted in a release of adsorbed Nd to solution with both pH and OM presumed to be the key factors controlling Nd attenuation. Collectively, the behavior of simulated contaminants within this replica trench provided unique insights into trench water biogeochemistry and contaminant cycling in a redox oscillatory environment.
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Affiliation(s)
- Andrew S Kinsela
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney 2052, Australia
| | - Mark W Bligh
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney 2052, Australia
| | - Xabier Vázquez-Campos
- NSW Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia
| | - Yingying Sun
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney 2052, Australia
| | - Marc R Wilkins
- NSW Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia
| | - M Josick Comarmond
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Brett Rowling
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Timothy E Payne
- Environmental Research Theme, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - T David Waite
- UNSW Water Research Centre and School of Civil and Environmental Engineering, The University of New South Wales, Sydney 2052, Australia
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25
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Wang L, Zhang X, Chen S, Meng F, Zhang D, Liu Y, Li M, Liu X, Huang X, Qu J. Spatial variation of dissolved organic nitrogen in Wuhan surface waters: Correlation with the occurrence of disinfection byproducts during the COVID-19 pandemic. WATER RESEARCH 2021; 198:117138. [PMID: 33895589 PMCID: PMC8036133 DOI: 10.1016/j.watres.2021.117138] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 05/04/2023]
Abstract
Intensified sanitization practices during the recent coronavirus disease-2019 (COVID-19) led to the release of chlorine-based disinfectants in surface water, potentially triggering the formation of disinfection byproducts (DBPs) in the presence of dissolved organic nitrogen (DON). Thus, a comprehensive investigation of DON's spatial distribution and its association with DBP occurrence in the surface water is urgently needed. In this study, a total of 51 water samples were collected from two rivers and four lakes in May 2020 in Wuhan to explore the regional variation of nitrogen (N) species, DON's compositional characteristics, and the three classes of DBP occurrence. In lakes, 53.0% to 86.3% of N existed as DON, with its concentration varying between 0.3-4.0 mg N/L. In contrast, NO3--N was the dominant N species in rivers. Spectral analysis revealed that DON in the lakes contained higher humic and fulvic materials with higher A254, A253/A203, SUVA254, and PIII+IV/PI+II+V ratios, while rivers had higher levels of hydrophilic compounds. Trihalomethanes (THMs) were the most prevalent DBPs in the surface waters, followed by N-nitrosamines and haloacetonitriles (HANs). The levels of N-nitrosamines (23.1-97.4 ng/L) increased significantly after the outbreak of the COVID-19 pandemic. Excessive DON in the surface waters was responsible for the formation of N-nitrosamines. This study confirmed that the presence of DON in surface water could result in DBP formation, especially N-nitrosamines, when disinfectants were discharged into surface water during the COVID-19 pandemic.
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Affiliation(s)
- Leyun Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Xian Zhang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Shanshan Chen
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Fanbin Meng
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yi Liu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Miao Li
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Xiang Liu
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Xia Huang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- School of Environment, Tsinghua University, Beijing 100084, China
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26
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Rizzo CB, Song X, de Barros FPJ, Chen X. Temporal flow variations interact with spatial physical heterogeneity to impact solute transport in managed river corridors. JOURNAL OF CONTAMINANT HYDROLOGY 2020; 235:103713. [PMID: 33031984 DOI: 10.1016/j.jconhyd.2020.103713] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 06/22/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
The interactions between surface water and groundwater in river corridors lead to temporal fluctuations in subsurface water fluxes which have a critical role on solute transport dynamics. In this work, we develop a framework to analyze the relative impacts of different temporal frequencies of the flow field in a spatially heterogeneous aquifer on solute transport. Our analysis indicates that the advection-dispersion equation behaves as a low-pass filter by wiping out the effect of high-frequency velocity fluctuations on the first two spatial moments of the solute plume, namely its center of mass and spreading. The concepts discussed in the theoretical analysis are then applied to understand solute transport dynamics at the 300 Area of the Hanford site (USA) adjacent to the Columbia River. We examine the temporal behavior of the solute plume's spatial moments for different temporal frequencies utilizing geostatistical parameters estimated in the 300 Area. Due to the proximity to the Columbia river, groundwater fluxes at the Hanford site are highly dynamic resulting in a large range of characteristic temporal frequencies. Nonetheless, similar to the theoretical analysis, our results show that the effect of high-frequency fluctuations is filtered, with most of the solute transport dynamics being controlled by fluctuations characterized by a large characteristic period.
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Affiliation(s)
- Calogero B Rizzo
- University of Southern California, Sonny Astani Department of Civil and Environmental Engineering, Los Angeles, CA, United States.
| | - Xuehang Song
- Pacific Northwest National Laboratory, Richland, WA, United States
| | - Felipe P J de Barros
- University of Southern California, Sonny Astani Department of Civil and Environmental Engineering, Los Angeles, CA, United States
| | - Xingyuan Chen
- Pacific Northwest National Laboratory, Richland, WA, United States
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27
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Cardarelli EL, Bargar JR, Francis CA. Diverse Thaumarchaeota Dominate Subsurface Ammonia-oxidizing Communities in Semi-arid Floodplains in the Western United States. MICROBIAL ECOLOGY 2020; 80:778-792. [PMID: 32535638 DOI: 10.1007/s00248-020-01534-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
Subsurface microbial communities mediate biogeochemical transformations that drive both local and ecosystem-level cycling of essential elements, including nitrogen. However, their study has been largely limited to the deep ocean, terrestrial mines, caves, and topsoils (< 30 cm). Here, we present regional insights into the microbial ecology of aerobic ammonia oxidation within the terrestrial subsurface of five semi-arid riparian sites spanning a 900-km N-S transect. We sampled sediments, profiled communities to depths of ≤ 10 m, and compared them to reveal trends regionally within and surrounding the Upper Colorado River Basin (CRB). The diversity and abundance of ammonia-oxidizing microbial communities were evaluated in the context of subsurface geochemistry by applying a combination of amoA (encoding ammonia monooxygenase subunit A) gene sequencing, quantitative PCR, and geochemical techniques. Analysis of 898 amoA sequences from ammonia-oxidizing archaea (AOA) and bacteria (AOB) revealed extensive ecosystem-scale diversity, including archaeal amoA sequences from four of the five major AOA lineages currently found worldwide as well as distinct AOA ecotypes associated with naturally reduced zones (NRZs) and hydrogeochemical zones (unsaturated, capillary fringe, and saturated). Overall, AOA outnumber AOB by 2- to 5000-fold over this regional scale, suggesting that AOA may play a prominent biogeochemical role in nitrification within terrestrial subsurface sediments.
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Affiliation(s)
- Emily L Cardarelli
- Department of Earth System Science, Stanford University, Stanford, CA, 94305-4216, USA
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Christopher A Francis
- Department of Earth System Science, Stanford University, Stanford, CA, 94305-4216, USA.
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28
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Liang Y, Ma R, Wang Y, Wang S, Qu L, Wei W, Gan Y. Hydrogeological controls on ammonium enrichment in shallow groundwater in the central Yangtze River Basin. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 741:140350. [PMID: 32886962 DOI: 10.1016/j.scitotenv.2020.140350] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/12/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
The controlling processes of excessive ammonium in surface water and groundwater in the central Yangtze River Basin remain unclear. In this study, monitoring of water levels and temporal-spatial distributions of major N compounds were implemented at the large Jiangshan plain and at the local site scale in the central Yangtze River Basin. The results indicate that the recharge, movement and transformation of ammonium were controlled by hydrogeological conditions. Manure and sewage from anthropogenic activities were identified as the main source of nitrogen compounds. The nitrogen loading into aquifers were governed by water table and groundwater flow. After entering subsurface soils, nitrification and dissimilatory nitrate reduction to ammonium (DNRA) were proposed as the ammonium consumption and production mechanisms, respectively, by combining the concentrations of ammonium‑nitrogen and nitrate‑nitrogen with the corresponding isotopic compositions. These microbially mediated processes controlling transport and transformation of nitrogen compounds were influenced by the seasonally varying groundwater flow regime that changed the redox conditions in the aquifers. In the subsurface environments, ammonium was converted to nitrate when sufficient oxygen supply was available, and this process was reversed under anoxic conditions along the groundwater flow path. A conceptual model for the reactive transport of nitrogen compounds jointly controlled by the vertical groundwater flows and biogeochemical processes was proposed, which provides new insights into the genesis of high ammonium groundwater.
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Affiliation(s)
- Ying Liang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Rui Ma
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
| | - Yanxin Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Shuo Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Le Qu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Wenhao Wei
- Geological Survey, China University of Geosciences, Wuhan 430074, China
| | - Yiqun Gan
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; MOE Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
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29
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Ohan JA, Saneiyan S, Lee J, Bartlow AW, Ntarlagiannis D, Burns SE, Colwell FS. Microbial and Geochemical Dynamics of an Aquifer Stimulated for Microbial Induced Calcite Precipitation (MICP). Front Microbiol 2020; 11:1327. [PMID: 32612598 PMCID: PMC7309221 DOI: 10.3389/fmicb.2020.01327] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/25/2020] [Indexed: 11/28/2022] Open
Abstract
Microbially induced calcite precipitation (MICP) is an alternative to existing soil stabilization techniques for construction and erosion. As with any biologically induced process in soils or aquifers, it is important to track changes in the microbial communities that occur as a result of the treatment. Our research assessed how native microbial communities developed in response to injections of reactants (dilute molasses as a carbon source; urea as a source of nitrogen and alkalinity) that promoted MICP in a shallow aquifer. Microbial community composition (16S rRNA gene) and ureolytic potential (ureC gene copy numbers) were also measured in groundwater and artificial sediment. Aquifer geochemistry showed evidence of sulfate reduction, nitrification, denitrification, ureolysis, and iron reduction during the treatment. The observed changes in geochemistry corresponded to microbial community succession in the groundwater and this matched parallel geophysical and mineralogical evidence of calcite precipitation in the aquifer. We detected an increase in the number of ureC genes in the microbial communities at the end of the injection period, suggesting an increase in the abundance of microbes possessing this gene as needed to hydrolyze urea and stimulate MICP. We identify geochemical and biological markers that highlight the microbial community response that can be used along with geophysical and geotechnical evidence to assess progress of MICP.
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Affiliation(s)
- J A Ohan
- Department of Microbiology, Oregon State University, Corvallis, OR, United States.,Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - S Saneiyan
- Department of Earth & Environmental Sciences, Rutgers University, Newark, NJ, United States
| | - J Lee
- College of Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Andrew W Bartlow
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - D Ntarlagiannis
- Department of Earth & Environmental Sciences, Rutgers University, Newark, NJ, United States
| | - S E Burns
- College of Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Frederick S Colwell
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
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30
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Ma J, Liu H, Zhang C, Ding K, Chen R, Liu S. Joint response of chemistry and functional microbial community to oxygenation of the reductive confined aquifer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137587. [PMID: 32135291 DOI: 10.1016/j.scitotenv.2020.137587] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/23/2020] [Accepted: 02/25/2020] [Indexed: 06/10/2023]
Abstract
Oxygen can enter into reductive aquifer through natural and artificial processes. However, the joint response of groundwater chemistry and functional microbial communities to oxygenation is not well understood due to the gap between taxonomic and functional microbial composition. Here, two wells named CZK15 and CZK22 at the second confined aquifer in Central China were in situ aerated, and the chemical parameters of groundwater and microbial communities in bio-trapping sand sediment were analysed during aeration. The microbial metabolic functions related to C, N, S, Fe transformation were predicted by Functional Annotation of Prokaryotic Taxa (FAPROTAX) approach and some key functional genes, such as phe, nah, narG, and soxB were verified by the real-time quantitative Polymerase Chain Reaction (qPCR) method. The biomass was promoted, microbial diversity fluctuated, and microbial composition changed remarkably with aeration mainly constrained by reduction-oxidation (redox) variation and SO42- concentration. Among functional microbes, aerobic chemoheterotrophs including aromatic compound degraders (also especially for relative abundance of phe and some nah gene) and methylotrophs are dramatically enriched interpreting dissolved oxygen (DO) consumption and total organic carbon (TOC) decomposing in sediment. Whilst fermenters and methanogen expectedly decreased during aeration. Denitrifying microbes and narG gene relative abundance increased corresponding to the NO3- increase after aeration, while microbes for N2 fixation, ammonification, and nitrification decreased relating to the source of NH4+. The sulfide oxidation causing increased SO42- was reflected by the blooming of sulfur-oxidizing microbes and soxB gene. Some sulfate reducers persisted in sediment after aeration due to sufficient SO42- as substrate. Fe(II) was mainly chemically oxidized as iron-oxidizing microbes were of low abundance and tended to decrease with aeration. The iron-reducing bacteria Geobacteraceae increased with aeration corresponding to the increased Fe(III) oxides formation. The findings of this study could have important implications in understanding the biogeochemical behaviours with cyclic redox conditions.
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Affiliation(s)
- Jie Ma
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China
| | - Hui Liu
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China.
| | - Chen Zhang
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China
| | - Kang Ding
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China
| | - Rong Chen
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China
| | - Shan Liu
- State Key Laboratory of Biogeology and Environmental Geology and School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan 430074, PR China
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Influence of Streambed Heterogeneity on Hyporheic Flow and Sorptive Solute Transport. WATER 2020. [DOI: 10.3390/w12061547] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The subsurface region where river water and groundwater actively mix (the hyporheic zone) plays an important role in conservative and reactive solute transport along rivers. Deposits of high-conductivity (K) sediments along rivers can strongly control hyporheic processes by channeling flow along preferential flow paths wherever they intersect the channel boundary. Our goal is to understand how sediment heterogeneity influences conservative and sorptive solute transport within hyporheic zones containing high- and low-K sediment facies types. The sedimentary architecture of high-K facies is modeled using commonly observed characteristics (e.g., volume proportion and mean length), and their spatial connectivity is quantified to evaluate its effect on hyporheic mixing dynamics. Numerical simulations incorporate physical and chemical heterogeneity by representing spatial variability in both K and in the sediment sorption distribution coefficient ( K d ). Sediment heterogeneity significantly enhances hyporheic exchange and skews solute breakthrough behavior, while in homogeneous sediments, interfacial flux and solute transport are instead controlled by geomorphology and local-scale riverbed topographies. The hyporheic zone is compressed in sediments with high sorptive capacity, which limits solute interactions to only a small portion of the sedimentary architecture and thus increases retention. Our results have practical implications for groundwater quality, including remediation strategies for contaminants of emerging concern.
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Zhang N, Bu X, Li Y, Zhang Y, Yuan S, Wen Z, Tong M, Lin L. Water Table Fluctuations Regulate Hydrogen Peroxide Production and Distribution in Unconfined Aquifers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4942-4951. [PMID: 32202769 DOI: 10.1021/acs.est.0c00487] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Significance of reactive oxygen species (ROS) in subsurface has been increasingly documented in recent years, whereas the mechanisms controlling ROS production and distribution in subsurface remain poorly understood. Here we show that water table fluctuations regulate the dynamics of hydrogen peroxide (H2O2) production and distribution in unconfined aquifers. In one hydrological year, we measured the dynamics of H2O2 distribution in an unconfined aquifer impacted by a 14 m water level fluctuation in the adjacent Yangtze River. H2O2 concentrations in groundwater attained up to 123 nM at rising water table stage in summer, but were low or even below the detection limit at the other stages of stable and falling water table. Lab experiments and kinetic models revealed that abiotic reactions between dissolved O2 and reduced species (i.e., Fe(II) and organic matter) were responsible for H2O2 production in the aquifers. Both field observations and reactive transport models unveiled that a rising water table developed a thermodynamically unstable banded zone in the unconfined aquifer in which elevated coexisting dissolved O2 and reduced species favored abiotic H2O2 production. Our findings provide fundamentals for understanding and predicting ROS distribution in unconfined aquifers, and constrain the significance of ROS in aquifers to specific temporal and spatial domains.
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Affiliation(s)
- Na Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, P. R. China
| | - Xiaochuang Bu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, P. R. China
| | - Yiming Li
- School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, P. R. China
| | - Yanting Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, P. R. China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, P. R. China
| | - Zhang Wen
- School of Environmental Studies, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, 430078, P. R. China
| | - Man Tong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, NO. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, P. R. China
| | - Li Lin
- Department of Water Environment Research, Changjiang River Scientific Research Institute, Wuhan, Hubei 430010, China
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33
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Cheng D, Neumann A, Yuan S, Liao W, Qian A. Oxidative Degradation of Organic Contaminants by FeS in the Presence of O 2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4091-4101. [PMID: 32142604 DOI: 10.1021/acs.est.9b07012] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Reductive transformation of organic contaminants by FeS in anoxic environments has been documented previously, whereas the transformation in oxic environments remains poorly understood. Here we show that phenol can be efficiently oxidized in oxic FeS suspension at circumneutral pH value. We found that hydroxyl radicals (•OH) were the predominant reactive oxidant and that a higher O2 content accelerated phenol degradation. Phenol oxidation depended on •OH production and utilization efficiency, i.e., phenol degraded per •OH produced. Low FeS contents (≤1 g/L) produced less •OH but higher utilization efficiency, while high contents produced more •OH but lower utilization efficiency. Consequently, the most favorable conditions for phenol oxidation occurred during the long-term interaction between dissolved O2 and low levels of FeS (i.e., ≤1 g/L). Mössbauer spectroscopy suggests that FeS oxidation to lepidocrocite initially produced an intermediate Fe(II) phase that could be explained by the apparent preferential oxidation of structural S(-II) relative to Fe(II), rendering a higher initial •OH yield upon unit of Fe(II) oxidation. Trichloroethylene can be also oxidized under similar conditions. Our results demonstrate that oxidative degradation of organic contaminants during the oxygenation of FeS can be a significant but currently underestimated pathway in both natural and engineered systems.
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Affiliation(s)
- Dong Cheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Anke Neumann
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Wenjuan Liao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
| | - Ao Qian
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan, Hubei 430078, PR China
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Xie W, Yuan S, Tong M, Ma S, Liao W, Zhang N, Chen C. Contaminant Degradation by •OH during Sediment Oxygenation: Dependence on Fe(II) Species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2975-2984. [PMID: 32023045 DOI: 10.1021/acs.est.9b04870] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
It has been documented that contaminants could be degraded by hydroxyl radicals (•OH) produced upon oxygenation of Fe(II)-bearing sediments. However, the dependence of contaminant degradation on sediment characteristics, particularly Fe(II) species, remains elusive. Here we assessed the impact of the abundance of Fe(II) species in sediments on contaminant degradation by •OH during oxygenation. Three natural sediments with different Fe(II) contents and species were oxygenated. During 10 h oxygenation of 200 g/L sediment suspension, 2 mg/L phenol was negligibly degraded for sandbeach sediment (Fe(II): 9.11 mg/g), but was degraded by 41% and 52% for lakeshore (Fe(II): 9.81 mg/g) and farmland (Fe(II): 19.05 mg/g) sediments, respectively. •OH produced from Fe(II) oxygenation was the key reactive oxidant. Sequential extractions, X-ray diffraction, Mössbauer, and X-ray absorption spectroscopy suggest that surface-adsorbed Fe(II) and mineral structural Fe(II) contributed predominantly to •OH production and phenol degradation. Control experiments with specific Fe(II) species and coordination structure analysis collectively suggest the likely rule that Fe(II) oxidation rate and its competition for •OH increase with the increase in electron-donating ability of the atoms (i.e., O) complexed to Fe(II), while the •OH yield decreases accordingly. The Fe(II) species with a moderate oxidation rate and •OH yield is most favorable for contaminant degradation.
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Affiliation(s)
- Wenjing Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Man Tong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Sicong Ma
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Wenjuan Liao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Na Zhang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 68 Jincheng Street, Wuhan 430074, PR P. R. China
| | - Chunmei Chen
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, P. R. China
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35
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Liao W, Ye Z, Yuan S, Cai Q, Tong M, Qian A, Cheng D. Effect of Coexisting Fe(III) (oxyhydr)oxides on Cr(VI) Reduction by Fe(II)-Bearing Clay Minerals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13767-13775. [PMID: 31702131 DOI: 10.1021/acs.est.9b05208] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fe(II)-bearing clay minerals are important electron sources for Cr(VI) reduction in subsurface environments. However, it is not clear how iron (oxyhydr)oxides impact Cr(VI) reduction by Fe(II)-bearing clays as the two minerals can coexist in soil and sediment aggregates. This study investigated Cr(VI) reduction in the mixed suspensions of reduced nontronite NAu-2 (rNAu-2) and ferrihydrite (Fe(II)/Cr(VI) = 3:1). When the mineral premixing time increased from 0 to 72 h, Cr(VI) reduction was accelerated prominently in the initial stage, while Cr(VI) sorption was inhibited drastically. Mineral premixing led to electron transfer from structural Fe(II) in rNAu-2 to ferrihydrite with formation of reactive-surface-associated Fe(II), which catalyzed ferrihydrite transformation to lepidocrocite. Reactive-surface-associated Fe(II) accelerated Cr(VI) reduction initially, and ferrihydrite transformation to lepidocrocite was responsible for the inhibited sorption. When the reactive-surface-associated Fe(II) was consumed in the initial stage, the Cr(VI) reduction rate decreased dramatically due to the limitation of slow electron transfer from structural Fe(II) in rNAu-2 to surface-reactive sites. The main reduction sites shifted from rNAu-2 to ferrihydrite/lepidocrocite when rNAu-2 coexisted with ferrihydrite. Our findings demonstrate that electron transfer between minerals has important implications for Cr(VI) and other high-valence contaminant reduction by Fe(II)-bearing clay minerals in subsurface environments.
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Affiliation(s)
- Wenjuan Liao
- State Key Laboratory of Biogeology and Environmental Geology , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Zilu Ye
- School of Environmental Studies , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Qizheng Cai
- School of Environmental Studies , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Man Tong
- State Key Laboratory of Biogeology and Environmental Geology , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Ao Qian
- State Key Laboratory of Biogeology and Environmental Geology , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
| | - Dong Cheng
- State Key Laboratory of Biogeology and Environmental Geology , China University of Geosciences , 388 Lumo Road , Wuhan 430074 , P. R. China
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Zelaya AJ, Parker AE, Bailey KL, Zhang P, Van Nostrand J, Ning D, Elias DA, Zhou J, Hazen TC, Arkin AP, Fields MW. High spatiotemporal variability of bacterial diversity over short time scales with unique hydrochemical associations within a shallow aquifer. WATER RESEARCH 2019; 164:114917. [PMID: 31387058 DOI: 10.1016/j.watres.2019.114917] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 06/10/2023]
Abstract
Understanding microbial community structure and function within the subsurface is critical to assessing overall quality and maintenance of groundwater; however, the factors that determine microbial community assembly, structure, and function in groundwater systems and their impact on water quality remains poorly understood. In this study, three shallow wells (FW301, FW303, FW305) in a non-contaminated shallow aquifer in the ENIGMA-Oak Ridge Field Research Center (Oak Ridge, TN) were sampled approximately 3 times a week over a period of three months to measure changes in groundwater geochemistry and microbial diversity. It was expected that the sampled microbial diversity from two historic field wells (FW301, FW303) would be relatively stable, while diversity from a newer well (FW305) would be less stable over time. The wells displayed some degree of hydrochemical variability over time unique to each well, with FW303 being overall the most stable well and FW301 being the most dynamic based upon dissolved oxygen, conductivity, and nitrate. Community analysis via ss-rRNA paired-end sequencing and distribution-based clustering revealed higher OTU richness, diversity, and variability in groundwater communities of FW301 than the other two wells for diversity binned over all time points. Microbial community composition of a given well was on average > 50% dissimilar to any other well at a given time (days), yet, functional gene diversity as measured with GeoChip remained relatively constant. Similarities in community structure across wells were observed with respect to the presence of 20 shared bacterial groups in all samples in all wells, although at varying levels over the tested time period. Similarity percentage (SIMPER) analysis revealed that variability in FW301 was largely attributed to low abundance, highly-transient populations, while variability in the most hydrochemically stable well (FW303) was due to fluctuations in more highly abundant and frequently present taxa. Additionally, the youngest well FW305 showed a dramatic shift in community composition towards the end of the sampling period that was not observed in the other wells, suggesting possible succession events over time. Time-series analysis using vector auto-regressive models and Granger causality showed unique relationships between richness and geochemistry over time in each well. These results indicate temporally dynamic microbial communities over short time scales, with day-to-day population shifts in local community structure influenced by available source community diversity and local groundwater hydrochemistry.
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Affiliation(s)
- Anna J Zelaya
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Microbiology & Immunology, Montana State University, Bozeman, MT, USA
| | - Albert E Parker
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Mathematical Sciences, Montana State University, Bozeman, MT, USA
| | - Kathryn L Bailey
- Division of Environmental Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Ping Zhang
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Joy Van Nostrand
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Daliang Ning
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Dwayne A Elias
- Division of Environmental Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA
| | - Terry C Hazen
- Department of Civil and Environmental Engineering, University of Tennesee, Knoxville, TN, USA
| | - Adam P Arkin
- Department of Bioengineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Matthew W Fields
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Microbiology & Immunology, Montana State University, Bozeman, MT, USA.
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Mailloux BJ, Kim C, Kichuk T, Nguyen K, Precht C, Wang S, Jewell TNM, Karaoz U, Brodie EL, Williams KH, Beller HR, Buchholz BA. Paired RNA Radiocarbon and Sequencing Analyses Indicate the Importance of Autotrophy in a Shallow Alluvial Aquifer. Sci Rep 2019; 9:10370. [PMID: 31316095 PMCID: PMC6637170 DOI: 10.1038/s41598-019-46663-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 07/01/2019] [Indexed: 11/08/2022] Open
Abstract
Determining the carbon sources for active microbial populations in the subsurface is a challenging but highly informative component of subsurface microbial ecology. This work developed a method to provide ecological insights into groundwater microbial communities by characterizing community RNA through its radiocarbon and ribosomal RNA (rRNA) signatures. RNA was chosen as the biomolecule of interest because rRNA constitutes the majority of RNA in prokaryotes, represents recently active organisms, and yields detailed taxonomic information. The method was applied to a groundwater filter collected from a shallow alluvial aquifer in Colorado. RNA was extracted, radiometrically dated, and the 16S rRNA was analyzed by RNA-Seq. The RNA had a radiocarbon signature (Δ14C) of -193.4 ± 5.6‰. Comparison of the RNA radiocarbon signature to those of potential carbon pools in the aquifer indicated that at least 51% of the RNA was derived from autotrophy, in close agreement with the RNA-Seq data, which documented the prevalence of autotrophic taxa, such as Thiobacillus and Gallionellaceae. Overall, this hybrid method for RNA analysis provided cultivation-independent information on the in-situ carbon sources of active subsurface microbes and reinforced the importance of autotrophy and the preferential utilization of dissolved over sedimentary organic matter in alluvial aquifers.
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Affiliation(s)
- Brian J Mailloux
- Environmental Science Department, Barnard College, NY, NY, 10027, New York, USA.
| | - Carol Kim
- Environmental Science Department, Barnard College, NY, NY, 10027, New York, USA
| | - Tess Kichuk
- Environmental Science Department, Barnard College, NY, NY, 10027, New York, USA
| | - Khue Nguyen
- Environmental Science Department, Barnard College, NY, NY, 10027, New York, USA
| | - Chandler Precht
- Environmental Science Department, Barnard College, NY, NY, 10027, New York, USA
| | - Shi Wang
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Talia N M Jewell
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ulas Karaoz
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Eoin L Brodie
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kenneth H Williams
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Harry R Beller
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Bruce A Buchholz
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, 94551-9900, USA
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Lefebvre P, Noël V, Lau KV, Jemison NE, Weaver KL, Williams KH, Bargar JR, Maher K. Isotopic Fingerprint of Uranium Accumulation and Redox Cycling in Floodplains of the Upper Colorado River Basin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3399-3409. [PMID: 30807121 DOI: 10.1021/acs.est.8b05593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Uranium (U) groundwater contamination is a major concern at numerous former mining and milling sites across the Upper Colorado River Basin (UCRB), USA, where U(IV)-bearing solids have accumulated within naturally reduced zones (NRZs). Understanding the processes governing U reduction and oxidation within NRZs is critical for assessing the persistence of U in groundwater. To evaluate the redox cycling of uranium, we measured the U concentrations and isotopic compositions (δ238U) of sediments and pore waters from four study sites across the UCRB that span a gradient in sediment texture and composition. We observe that U accumulation occurs primarily within fine-grained (low-permeability) NRZs that show active redox variations. Low-permeability NRZs display high accumulation and low export of U, with internal redox cycling of U. In contrast, within high-permeability NRZs, U is remobilized under oxidative conditions, possibly without any fractionation, and transported outside the NRZs. The low δ238U of sediments outside of defined NRZs suggests that these reduced zones act as additional U sources. Collectively, our results indicate that fine-grained NRZs have a greater potential to retain uranium, whereas NRZs with higher permeability may constitute a more-persistent but dilute U source.
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Affiliation(s)
- Pierre Lefebvre
- Department of Earth System Science , Stanford University , Stanford , California 94305 , United States
- Département de Géosciences , Ecole Normale Supérieure , Paris 75005 , France
| | - Vincent Noël
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Kimberly V Lau
- Department of Geological Sciences , Stanford University , Stanford , California 94305 , United States
| | - Noah E Jemison
- Department of Geology , University of Illinois at Urbana-Champaign , Champaign , Illinois 61820 , United States
| | - Karrie L Weaver
- Department of Earth System Science , Stanford University , Stanford , California 94305 , United States
| | - Kenneth H Williams
- Earth Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Kate Maher
- Department of Earth System Science , Stanford University , Stanford , California 94305 , United States
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Arora B, Wainwright HM, Dwivedi D, Vaughn LJS, Curtis JB, Torn MS, Dafflon B, Hubbard SS. Evaluating temporal controls on greenhouse gas (GHG) fluxes in an Arctic tundra environment: An entropy-based approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 649:284-299. [PMID: 30173035 DOI: 10.1016/j.scitotenv.2018.08.251] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/23/2018] [Accepted: 08/19/2018] [Indexed: 06/08/2023]
Abstract
There is significant spatial and temporal variability associated with greenhouse gas (GHG) fluxes in high-latitude Arctic tundra environments. The objectives of this study are to investigate temporal variability in CO2 and CH4 fluxes at Barrow, AK and to determine the factors causing this variability using a novel entropy-based classification scheme. In particular, we analyzed which geomorphic, soil, vegetation and climatic properties most explained the variability in GHG fluxes (opaque chamber measurements) during the growing season over three successive years. Results indicate that multi-year variability in CO2 fluxes was primarily associated with soil temperature variability as well as vegetation dynamics during the early and late growing season. Temporal variability in CH4 fluxes was primarily associated with changes in vegetation during the growing season and its interactions with primary controls like seasonal thaw. Polygonal ground features, which are common to Arctic regions, also demonstrated significant multi-year variability in GHG fluxes. Our results can be used to prioritize field sampling strategies, with an emphasis on measurements collected at locations and times that explain the most variability in GHG fluxes. For example, we found that sampling primary environmental controls at the centers of high centered polygons in the month of September (when freeze-back period begins) can provide significant constraints on GHG flux variability - a requirement for accurately predicting future changes to GHG fluxes. Overall, entropy results document the impact of changing environmental conditions (e.g., warming, growing season length) on GHG fluxes, thus providing clues concerning the manner in which ecosystem properties may be shifted regionally in a future climate.
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Affiliation(s)
- Bhavna Arora
- Lawrence Berkeley National Laboratory, Berkeley, United States of America.
| | | | - Dipankar Dwivedi
- Lawrence Berkeley National Laboratory, Berkeley, United States of America
| | - Lydia J S Vaughn
- Lawrence Berkeley National Laboratory, Berkeley, United States of America
| | - John B Curtis
- University of Colorado, Boulder, United States of America
| | - Margaret S Torn
- Lawrence Berkeley National Laboratory, Berkeley, United States of America
| | - Baptiste Dafflon
- Lawrence Berkeley National Laboratory, Berkeley, United States of America
| | - Susan S Hubbard
- Lawrence Berkeley National Laboratory, Berkeley, United States of America
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Fu H, Zhang H, Sui Y, Hu N, Ding D, Ye Y, Li G, Wang Y, Dai Z. Transformation of uranium species in soil during redox oscillations. CHEMOSPHERE 2018; 208:846-853. [PMID: 30068027 DOI: 10.1016/j.chemosphere.2018.06.059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 05/19/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
Redox oscillation is commonly found in near-surface environment, where soils are often polluted with many redox active contaminants, including uranium (U). In order to investigate the transformation of U species in near-surface soil under redox oscillations conditions, redox oscillations and reduction experiments were performed, biogeochemical parameters and native microbial community composition were monitored, main elements on the surface of solid-phase were analyzed by XPS, and labile U(IV) species and stable U(IV) species in solid-phase were provisionally defined using an anoxic 1 M sodium bicarbonate extraction. It was found that redox oscillations slightly increased the water-soluble U but significantly increased the stable U(IV) species (P < 0.05) in soil. In reduction experiment, there was upper limit value for percentage of stable U(IV) species, and the labile U(IV) species could not transform to stable U(IV) species in a short period of time under reduction conditions. The redox transition of Fe enriched on the surface of soil and the conversion of microbial community composition played a major role in speciation transformation of U under redox oscillations conditions. In addition, sequential extraction revealed that the increase of stable U(IV) species content reflected the U speciation transition from acetate extract to more recalcitrant hydroxylamine extract. The finding provides a potential method for improving the stability of U when bio-reduction is used to remediate the U-contaminated soils.
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Affiliation(s)
- Haiying Fu
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China; School of Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China
| | - Hui Zhang
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
| | - Yang Sui
- School of Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China; Hunan Taohuajiang Nuclear Power Co., Ltd, Yiyang, 413000, China
| | - Nan Hu
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
| | - Dexin Ding
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China; School of Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China.
| | - Yongjun Ye
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China; School of Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China
| | - Guangyue Li
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
| | - Yongdong Wang
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
| | - Zhongran Dai
- Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
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Christensen JN, Dafflon B, Shiel AE, Tokunaga TK, Wan J, Faybishenko B, Dong W, Williams KH, Hobson C, Brown ST, Hubbard SS. Using strontium isotopes to evaluate the spatial variation of groundwater recharge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:672-685. [PMID: 29758424 DOI: 10.1016/j.scitotenv.2018.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Recharge of alluvial aquifers is a key component in understanding the interaction between floodplain vadose zone biogeochemistry and groundwater quality. The Rifle Site (a former U-mill tailings site) adjacent to the Colorado River is a well-established field laboratory that has been used for over a decade for the study of biogeochemical processes in the vadose zone and aquifer. This site is considered an exemplar of both a riparian floodplain in a semiarid region and a post-remediation U-tailings site. In this paper we present Sr isotopic data for groundwater and vadose zone porewater samples collected in May and July 2013 to build a mixing model for the fractional contribution of vadose zone porewater (i.e. recharge) to the aquifer and its variation across the site. The vadose zone porewater contribution to the aquifer ranged systematically from 0% to 38% and appears to be controlled largely by the microtopography of the site. The area-weighted average contribution across the site was 8% corresponding to a net recharge of 7.5 cm. Given a groundwater transport time across the site of ~1.5 to 3 years, this translates to a recharge rate between 5 and 2.5 cm/yr, and with the average precipitation to the site implies a loss from the vadose zone due to evapotranspiration of 83% to 92%, both ranges are in good agreement with previously published results by independent methods. A uranium isotopic (234U/238U activity ratios) mixing model for groundwater and surface water samples indicates that a ditch across the site is hydraulically connected to the aquifer and locally significantly affects groundwater. Groundwater samples with high U concentrations attributed to natural bio-reduced zones have 234U/238U activity ratios near 1, suggesting that the U currently being released to the aquifer originated from the former U-mill tailings.
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Affiliation(s)
- John N Christensen
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States.
| | - Baptiste Dafflon
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Alyssa E Shiel
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, United States
| | - Tetsu K Tokunaga
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Jiamin Wan
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Boris Faybishenko
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Wenming Dong
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Kenneth H Williams
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Chad Hobson
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Shaun T Brown
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Susan S Hubbard
- Earth and Environmental Science Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
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Pan D, Williams KH, Robbins MJ, Weber KA. Uranium Retention in a Bioreduced Region of an Alluvial Aquifer Induced by the Influx of Dissolved Oxygen. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8133-8145. [PMID: 29996052 DOI: 10.1021/acs.est.8b00903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Reduced zones in the subsurface represent biogeochemically active hotspots enriched in buried organic matter and reduced metals. Within a shallow alluvial aquifer located near Rifle, CO, reduced zones control the fate and transport of uranium (U). Though an influx of dissolved oxygen (DO) would be expected to mobilize U, we report U immobilization. Groundwater U concentrations decreased following delivery of DO (21.6 mg O2/well/h). After 23 days of DO delivery, injection of oxygenated groundwater was paused and resulted in the rebound of groundwater U concentrations to preinjection levels. When DO delivery resumed (day 51), groundwater U concentrations again decreased. The injection was halted on day 82 again and resulted in a rebound of groundwater U concentrations. DO delivery rate was increased to 54 mg O2/well/h (day 95) whereby groundwater U concentrations increased. Planktonic cell abundance remained stable throughout the experiment, but virus-to-microbial cell ratio increased 1.8-3.4-fold with initial DO delivery, indicative of microbial activity in response to DO injection. Together, these results indicate that the redox-buffering capacity of reduced sediments can prevent U mobilization, but could be overcome as delivery rate or oxidant concentration increases, mobilizing U.
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Affiliation(s)
- Donald Pan
- School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Kenneth H Williams
- Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Mark J Robbins
- Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Karrie A Weber
- School of Biological Sciences , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
- Department of Earth and Atmospheric Sciences , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
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Bone SE, Cahill MR, Jones ME, Fendorf S, Davis J, Williams KH, Bargar JR. Oxidative Uranium Release from Anoxic Sediments under Diffusion-Limited Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11039-11047. [PMID: 28876920 DOI: 10.1021/acs.est.7b02241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Uranium (U) contamination occurs as a result of mining and ore processing; often in alluvial aquifers that contain organic-rich, reduced sediments that accumulate tetravalent U, U(IV). Uranium(IV) is sparingly soluble, but may be mobilized upon exposure to nitrate (NO3-) and oxygen (O2), which become elevated in groundwater due to seasonal fluctuations in the water table. The extent to which oxidative U mobilization can occur depends upon the transport properties of the sediments, the rate of U(IV) oxidation, and the availability of inorganic reductants and organic electron donors that consume oxidants. We investigated the processes governing U release upon exposure of reduced sediments to artificial groundwater containing O2 or NO3- under diffusion-limited conditions. Little U was mobilized during the 85-day reaction, despite rapid diffusion of groundwater within the sediments and the presence of nonuraninite U(IV) species. The production of ferrous iron and sulfide in conjunction with rapid oxidant consumption suggested that the sediments harbored large concentrations of bioavailable organic carbon that fueled anaerobic microbial respiration and stabilized U(IV). Our results suggest that seasonal influxes of O2 and NO3- may cause only localized mobilization of U without leading to export of U from the reducing sediments when ample organic carbon is present.
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Affiliation(s)
- Sharon E Bone
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | | | - Morris E Jones
- Stanford University , Stanford, California 94305, United States
| | - Scott Fendorf
- Stanford University , Stanford, California 94305, United States
| | - James Davis
- U.S. Geological Survey, Menlo Park, California 94025, United States
| | - Kenneth H Williams
- Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - John R Bargar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
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Abstract
Soils account for the largest terrestrial pool of carbon and have the potential for even greater quantities of carbon sequestration. Typical soil carbon (C) stocks used in global carbon models only account for the upper 1 meter of soil. Previously unaccounted for deep carbon pools (>1 m) were generally considered to provide a negligible input to total C contents and represent less dynamic C pools. Here we assess deep soil C pools associated with an alluvial floodplain ecosystem transitioning from agricultural production to restoration of native vegetation. We analyzed the soil organic carbon (SOC) concentrations of 87 surface soil samples (0–15 cm) and 23 subsurface boreholes (0–3 m). We evaluated the quantitative importance of the burial process in the sequestration of subsurface C and found our subsurface soils (0–3 m) contained considerably more C than typical C stocks of 0–1 m. This deep unaccounted soil C could have considerable implications for global C accounting. We compared differences in surface soil C related to vegetation and land use history and determined that flooding restoration could promote greater C accumulation in surface soils. We conclude deep floodplain soils may store substantial quantities of C and floodplain restoration should promote active C sequestration.
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