1
|
Ho MS, Vettese GF, Morris K, Lloyd JR, Boothman C, Bower WR, Shaw S, Law GTW. Retention of immobile Se(0) in flow-through aquifer column systems during bioreduction and oxic-remobilization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155332. [PMID: 35460788 DOI: 10.1016/j.scitotenv.2022.155332] [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: 02/25/2022] [Revised: 04/12/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Selenium (Se) is a toxic contaminant with multiple anthropogenic sources, including 79Se from nuclear fission. Se mobility in the geosphere is generally governed by its oxidation state, therefore understanding Se speciation under variable redox conditions is important for the safe management of Se contaminated sites. Here, we investigate Se behavior in sediment groundwater column systems. Experiments were conducted with environmentally relevant Se concentrations, using a range of groundwater compositions, and the impact of electron-donor (i.e., biostimulation) and groundwater sulfate addition was examined over a period of 170 days. X-Ray Absorption Spectroscopy and standard geochemical techniques were used to track changes in sediment associated Se concentration and speciation. Electron-donor amended systems with and without added sulfate retained up to 90% of added Se(VI)(aq), with sediment associated Se speciation dominated by trigonal Se(0) and possibly trace Se(-II); no Se colloid formation was observed. The remobilization potential of the sediment associated Se species was then tested in reoxidation and seawater intrusion perturbation experiments. In all treatments, sediment associated Se (i.e., trigonal Se(0)) was largely resistant to remobilization over the timescale of the experiments (170 days). However, in the perturbation experiments, less Se was remobilized from sulfidic sediments, suggesting that previous sulfate-reducing conditions may buffer Se against remobilization and migration.
Collapse
Affiliation(s)
- Mallory S Ho
- Radiochemistry Unit, Department of Chemistry, University of Helsinki, 00014, Finland
| | - Gianni F Vettese
- Radiochemistry Unit, Department of Chemistry, University of Helsinki, 00014, Finland
| | - Katherine Morris
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL, UK.
| | - Jonathan R Lloyd
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL, UK
| | - Christopher Boothman
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL, UK
| | - William R Bower
- Radiochemistry Unit, Department of Chemistry, University of Helsinki, 00014, Finland
| | - Samuel Shaw
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL, UK
| | - Gareth T W Law
- Radiochemistry Unit, Department of Chemistry, University of Helsinki, 00014, Finland.
| |
Collapse
|
2
|
Williamson AJ, Lloyd JR, Boothman C, Law GTW, Shaw S, Small JS, Vettese GF, Williams HA, Morris K. Biogeochemical Cycling of 99Tc in Alkaline Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15862-15872. [PMID: 34825817 DOI: 10.1021/acs.est.1c04416] [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: 06/13/2023]
Abstract
99Tc will be present in significant quantities in radioactive wastes including intermediate-level waste (ILW). The internationally favored concept for disposing of higher activity radioactive wastes including ILW is via deep geological disposal in an underground engineered facility located ∼200-1000 m deep. Typically, in the deep geological disposal environment, the subsurface will be saturated, cement will be used extensively as an engineering material, and iron will be ubiquitous. This means that understanding Tc biogeochemistry in high pH, cementitious environments is important to underpin safety case development. Here, alkaline sediment microcosms (pH 10) were incubated under anoxic conditions under "no added Fe(III)" and "with added Fe(III)" conditions (added as ferrihydrite) at three Tc concentrations (10-11, 10-6, and 10-4 mol L-1). In the 10-6 mol L-1 Tc experiments with no added Fe(III), ∼35% Tc(VII) removal occurred during bioreduction. Solvent extraction of the residual solution phase indicated that ∼75% of Tc was present as Tc(IV), potentially as colloids. In both biologically active and sterile control experiments with added Fe(III), Fe(II) formed during bioreduction and >90% Tc was removed from the solution, most likely due to abiotic reduction mediated by Fe(II). X-ray absorption spectroscopy (XAS) showed that in bioreduced sediments, Tc was present as hydrous TcO2-like phases, with some evidence for an Fe association. When reduced sediments with added Fe(III) were air oxidized, there was a significant loss of Fe(II) over 1 month (∼50%), yet this was coupled to only modest Tc remobilization (∼25%). Here, XAS analysis suggested that with air oxidation, partial incorporation of Tc(IV) into newly forming Fe oxyhydr(oxide) minerals may be occurring. These data suggest that in Fe-rich, alkaline environments, biologically mediated processes may limit Tc mobility.
Collapse
Affiliation(s)
- Adam J Williamson
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
- CENBG-Équipe Radioactivité et Environnement, UMR 5797, CNRS-IN2P3/Université de Bordeaux, 19 chemin du Solarium, CS 10120, 33175 Gradignan, France
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Christopher Boothman
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Gareth T W Law
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - Samuel Shaw
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| | - Joe S Small
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
- National Nuclear Laboratory, Risley, Warrington, Cheshire WA3 6AE, U.K
| | - Gianni F Vettese
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - Heather A Williams
- Department of Nuclear Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, U.K
| | - Katherine Morris
- Research Centre for Radwaste Disposal and Williamson Research Centre for Molecular Environmental Science, Department of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Manchester M13 9PL, U.K
| |
Collapse
|
3
|
Bioelectrochemical Systems for Groundwater Remediation: The Development Trend and Research Front Revealed by Bibliometric Analysis. WATER 2019. [DOI: 10.3390/w11081532] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
: Due to the deficiency of fresh water resources and the deterioration of groundwater quality worldwide, groundwater remedial technologies are especially crucial for preventing groundwater pollution and protecting the precious groundwater resource. Among the remedial alternatives, bioelectrochemical systems have unique advantages on both economic and technological aspects. However, it is rare to see a deep study focused on the information mining and visualization of the publications in this field, and research that can reveal and visualize the development trajectory and trends is scarce. Therefore, this study summarizes the published information in this field from the Web of Science Core Collection of the last two decades (1999–2018) and uses Citespace to quantitatively visualize the relationship of authors, published countries, organizations, funding sources, and journals and detect the research front by analyzing keywords and burst terms. The results indicate that the studies focused on bioelectrochemical systems for groundwater remediation have had a significant increase during the last two decades, especially in China, Germany and Italy. The national research institutes and universities of the USA and the countries mentioned above dominate the research. Environmental Science & Technology, Applied and Environmental Microbiology, and Water Research are the most published journals in this field. The network maps of the keywords and burst terms suggest that reductive microbial diversity, electron transfer, microbial fuel cell, etc., are the research hotspots in recent years, and studies focused on microbial enrichment culture, energy supply/recovery, combined pollution remediation, etc., should be enhanced in future.
Collapse
|
4
|
Thorpe CL, Williams HA, Boothman C, Lloyd JR, Morris K. Positron emission tomography to visualise in-situ microbial metabolism in natural sediments. Appl Radiat Isot 2019; 144:104-110. [DOI: 10.1016/j.apradiso.2018.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
|
5
|
Boyer A, Hatat-Fraile M, Passeport E. Biogeochemical Controls on Strontium Fate at the Sediment-Water Interface of Two Groundwater-Fed Wetlands with Contrasting Hydrologic Regimes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8365-8372. [PMID: 29933694 DOI: 10.1021/acs.est.8b01876] [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
Radioactive strontium (Sr) is a common groundwater contaminant at many nuclear sites. Its natural retention in groundwater-fed wetlands is an attractive remediation strategy. However, at present, the biogeochemical mechanisms controlling Sr transport at the sediment-water interface are poorly understood. In this field study, Sr fate was investigated in two wetlands with contrasting vegetation and hydrologic regimes. The marsh was an open-water wetland with constant water table and no emergent vegetation. The swamp was vegetated with fluctuating water levels and a thick mat of submerged cattail litter in the water column. High-resolution porewater Sr concentrations and solid-phase sediment Sr species revealed distinct profiles between the two wetlands. The marsh exhibited a strongly reduced environment and sharp concentration peaks at the sediment-water interface. In contrast, the smaller concentration gradients of the swamp resulted in a reduced flux of Sr to the surface water. The organic fraction of the sediment dominated Sr retention compared to the inorganic iron and manganese oxides. However, the marsh had a significant fraction of recalcitrant Sr presumably due to its incorporation into sulfur and/or carbonate minerals. These results suggest that vegetated wetlands with fluctuating hydrologic regimes could act as efficient sinks for Sr pollution.
Collapse
Affiliation(s)
- Antoine Boyer
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street , Toronto , M5S 3E5 , Canada
| | - Mélisa Hatat-Fraile
- Department of Civil and Mineral Engineering , University of Toronto , 35 St George St. , Toronto , M5S 1A4 , Canada
| | - Elodie Passeport
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street , Toronto , M5S 3E5 , Canada
- Department of Civil and Mineral Engineering , University of Toronto , 35 St George St. , Toronto , M5S 1A4 , Canada
| |
Collapse
|
6
|
Masters-Waage NK, Morris K, Lloyd JR, Shaw S, Mosselmans JFW, Boothman C, Bots P, Rizoulis A, Livens FR, Law GTW. Impacts of Repeated Redox Cycling on Technetium Mobility in the Environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:14301-14310. [PMID: 29144125 DOI: 10.1021/acs.est.7b02426] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Technetium is a problematic contaminant at nuclear sites and little is known about how repeated microbiologically mediated redox cycling impacts its fate in the environment. We explore this question in sediments representative of the Sellafield Ltd. site, UK, over multiple reduction and oxidation cycles spanning ∼1.5 years. We found the amount of Tc remobilised from the sediment into solution significantly decreased after repeated redox cycles. X-ray Absorption Spectroscopy (XAS) confirmed that sediment bound Tc was present as hydrous TcO2-like chains throughout experimentation and that Tc's increased resistance to remobilization (via reoxidation to soluble TcO4-) resulted from both shortening of TcO2 chains during redox cycling and association of Tc(IV) with Fe phases in the sediment. We also observed that Tc(IV) remaining in solution during bioreduction was likely associated with colloidal magnetite nanoparticles. These findings highlight crucial links between Tc and Fe biogeochemical cycles that have significant implications for Tc's long-term environmental mobility, especially under ephemeral redox conditions.
Collapse
Affiliation(s)
- Nicholas K Masters-Waage
- Centre for Radiochemistry Research, School of Chemistry, The University of Manchester , M13 9PL, Manchester, United Kingdom
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Katherine Morris
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Jonathan R Lloyd
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Samuel Shaw
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - J Frederick W Mosselmans
- Diamond Light Source Ltd ., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
| | - Christopher Boothman
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Pieter Bots
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Athanasios Rizoulis
- Research Centre for Radwaste Disposal and Williamson Research Centre, School of Earth and Environmental Sciences, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Francis R Livens
- Centre for Radiochemistry Research, School of Chemistry, The University of Manchester , M13 9PL, Manchester, United Kingdom
| | - Gareth T W Law
- Centre for Radiochemistry Research, School of Chemistry, The University of Manchester , M13 9PL, Manchester, United Kingdom
| |
Collapse
|