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Ighalo JO, Chen Z, Ohoro CR, Oniye M, Igwegbe CA, Elimhingbovo I, Khongthaw B, Dulta K, Yap PS, Anastopoulos I. A review of remediation technologies for uranium-contaminated water. CHEMOSPHERE 2024; 352:141322. [PMID: 38296212 DOI: 10.1016/j.chemosphere.2024.141322] [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: 10/24/2023] [Revised: 01/24/2024] [Accepted: 01/27/2024] [Indexed: 02/09/2024]
Abstract
Uranium is a naturally existing radioactive element present in the Earth's crust. It exhibits lithophilic characteristics, indicating its tendency to be located near the surface of the Earth and tightly bound to oxygen. It is ecotoxic, hence the need for its removal from the aqueous environment. This paper focuses on the variety of water treatment processes for the removal of uranium from water and this includes physical (membrane separation, adsorption and electrocoagulation), chemical (ion exchange, photocatalysis and persulfate reduction), and biological (bio-reduction and biosorption) approaches. It was observed that membrane filtration and ion exchange are the most popular and promising processes for this application. Membrane processes have high throughput but with the challenge of high power requirements and fouling. Besides high pH sensitivity, ion exchange does not have any major challenges related to its application. Several other unique observations were derived from this review. Chitosan/Chlorella pyrenoidosa composite adsorbent bearing phosphate ligand, hydroxyapatite aerogel and MXene/graphene oxide composite has shown super-adsorbent performance (>1000 mg/g uptake capacity) for uranium. Ultrafiltration (UF) membranes, reverse osmosis (RO) membranes and electrocoagulation have been observed not to go below 97% uranium removal/conversion efficiency for most cases reported in the literature. Heat persulfate reduction has been explored quite recently and shown to achieve as high as 86% uranium reduction efficiency. We anticipate that future studies would explore hybrid processes (which are any combinations of multiple conventional techniques) to solve various aspects of the process design and performance challenges.
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Affiliation(s)
- Joshua O Ighalo
- Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B. 5025, Awka, Nigeria; Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, KS 66506, USA.
| | - Zhonghao Chen
- Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Chinemerem R Ohoro
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, 11 Hoffman St, Potchefstroom 2520, South Africa
| | - Mutiat Oniye
- Department of Chemical and Material Science, School of Engineering and Digital Sciences, Nazarbayev University, Astana, 010000 Kazakhstan
| | - Chinenye Adaobi Igwegbe
- Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B. 5025, Awka, Nigeria; Department of Applied Bioeconomy, Wroclaw University of Environmental and Life Sciences, 51-630 Wroclaw, Poland
| | - Isaiah Elimhingbovo
- Department of Animal and Environmental Biology, University of Benin, Benin City, Nigeria
| | - Banlambhabok Khongthaw
- Faculty of Applied Sciences and Biotechnology, Shoolini University, Solan, Himachal Pradesh, 173229, India
| | - Kanika Dulta
- Department of Food Technology, School of Applied and Life Sciences, Uttaranchal University, Dehradun-248007, Uttarakhand, India
| | - Pow-Seng Yap
- Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Ioannis Anastopoulos
- Department of Agriculture, University of Ioannina, UoI Kostaki Campus, Arta 47100, Greece
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Lu J, Geng R, Zhang H, Yu Z, Chen T, Zhang B. Concurrent reductive decontamination of chromium (VI) and uranium (VI) in groundwater by Fe(0)-based autotrophic bioprocess. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131222. [PMID: 36989793 DOI: 10.1016/j.jhazmat.2023.131222] [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: 01/14/2023] [Revised: 02/23/2023] [Accepted: 03/14/2023] [Indexed: 05/03/2023]
Abstract
The co-presence of chromium (VI) [Cr(VI)] and uranium (VI) [U(VI)] is widely found in groundwater, imposing severe risks on human health. Although zerovalent iron [Fe(0)] supports superb performance for bioreduction of Cr(VI) and U(VI) individually, the biogeochemical process involving their concurrent removal with Fe(0) as electron donor remains unexplored. In the 6-d batch study, 86.1% ± 0.7% of Cr(VI) was preferentially eliminated, while 78.4% ± 0.5% of U(VI) removal was achieved simultaneously. Efficient removal of Cr(VI) (100%) and U(VI) (51.2% ∼ 100%) was also obtained in a continuous 160-d column experiment. As a result, Cr(VI) and U(VI) were reduced to less mobile Cr(III) and insoluble U(IV), respectively. 16 S rRNA sequencing was performed to investigate the dynamics of microbial community. Delftia, Acinetobacter, Pseudomonas and Desulfomicrobium were the major contributors mediating the bioreduction process. The initial Cr(VI) and hydraulic retention time (HRT) incurred pronounced effects on community diversity, which in turn altered the reactor's performance. The enrichment of Cr(VI) resistance (chrA), U(VI) reduction (dsrA) and Fe(II) oxidation (mtrA) genes were observed by reverse transcription qPCR. Cytochrome c, glutathione and NADH as well as VFAs and gas metabolites also involved in the bioprocess. This study demonstrated a promising approach for removing the combined contaminants of Cr(VI) and U(VI) in groundwater.
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Affiliation(s)
- Jianping Lu
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China
| | - Rongyue Geng
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China
| | - Han Zhang
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China.
| | - Zhen Yu
- Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, PR China
| | - Tao Chen
- School of Environment, South China Normal University, University Town, Guangzhou 510006, PR China.
| | - Baogang Zhang
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China
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Lu J, Zhang B, Geng R, Lian G, Dong H. Independent and synergistic bio-reductions of uranium (VI) driven by zerovalent iron in aquifer. WATER RESEARCH 2023; 233:119778. [PMID: 36871383 DOI: 10.1016/j.watres.2023.119778] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/10/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
Zerovalent iron [Fe(0)] can donate electron for bioprocess, but microbial uranium (VI) [U(VI)] reduction driven by Fe(0) is still poorly understood. In this study, Fe(0) supported U(VI) bio-reduction was steadily achieved in the 160-d continuous-flow biological column. The maximum removal efficiency and capacity of U(VI) were 100% and 46.4 ± 0.52 g/(m3·d) respectively, and the longevity of Fe(0) increased by 3.09 times. U(VI) was reduced to solid UO2, while Fe(0) was finally oxidized to Fe(III). Autotrophic Thiobacillus achieved U(VI) reduction coupled to Fe(0) oxidation, verified by pure culture. H2 produced from Fe(0) corrosion was consumed by autotrophic Clostridium for U(VI) reduction. The detected residual organic intermediates were biosynthesized with energy released from Fe(0) oxidation and utilized by heterotrophic Desulfomicrobium, Bacillus and Pseudomonas to reduce U(VI). Metagenomic analysis found the upregulated genes for U(VI) reduction (e.g., dsrA and dsrB) and Fe(II) oxidation (e.g., CYC1 and mtrA). These functional genes were also transcriptionally expressed. Cytochrome c and glutathione responsible for electron transfer also contributed to U(VI) reduction. This study reveals the independent and synergistic pathways for Fe(0)-dependent U(VI) bio-reduction, providing promising remediation strategy for U(VI)-polluted aquifers.
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Affiliation(s)
- Jianping Lu
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China
| | - Baogang Zhang
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China.
| | - Rongyue Geng
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, School of Water Resources and Environment, China University of Geosciences Beijing, Beijing 100083, PR China
| | - Guoxi Lian
- School of Environment, Beijing Normal University, Beijing 100875, PR China; The Fourth Research and Design Engineering Institute of China National Nuclear Corporation, Shijiazhuang 050021, PR China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, School of Earth Science and Resources, China University of Geosciences Beijing, Beijing 100083, PR China
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You W, Peng W, Tian Z, Zheng M. Uranium bioremediation with U(VI)-reducing bacteria. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149107. [PMID: 34325147 DOI: 10.1016/j.scitotenv.2021.149107] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Uranium (U) pollution is an environmental hazard caused by the development of the nuclear industry. Microbial reduction of hexavalent uranium (U(VI)) to tetravalent uranium (U(IV)) reduces U solubility and mobility and has been proposed as an effective method to remediate uranium contamination. In this review, U(VI) remediation with respect to U(VI)-reducing bacteria, mechanisms, influencing factors, products, and reoxidation are systematically summarized. Reportedly, some metal- and sulfate-reducing bacteria possess excellent U(VI) reduction capability through mechanisms involving c-type cytochromes, extracellular pili, electron shuttle, or thioredoxin reduction. In situ remediation has been demonstrated as an ideal strategy for large-scale degradation of uranium contaminants than ex situ. However, U(VI) reduction efficiency can be affected by various factors, including pH, temperature, bicarbonate, electron donors, and coexisting metal ions. Furthermore, it is noteworthy that the reduction products could be reoxidized when exposed to oxygen and nitrate, inevitably compromising the remediation effects, especially for non-crystalline U(IV) with weak stability.
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Affiliation(s)
- Wenbo You
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Wanting Peng
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Zhichao Tian
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Maosheng Zheng
- Key Laboratory of Regional Energy Systems Optimization, Ministry of Education, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
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Hao L, Zhang B, Feng C, Zhang Z, Lei Z, Shimizu K. Human health risk of vanadium in farmland soils near various vanadium ore mining areas and bioremediation assessment. CHEMOSPHERE 2021; 263:128246. [PMID: 33297193 DOI: 10.1016/j.chemosphere.2020.128246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 06/12/2023]
Abstract
Various kinds of vanadium (V) ore mining areas produced serious contamination have been widely recognized, while less relevant research was about the associated health risk and V distribution level for farmland soils around. This study assessed the contamination characteristics and associated human health risk of V in the surface farmland soils near various V ore mining areas. The bioremediation of V contamination by indigenous microbes from them was also evaluated. The farmland soils near stone coal area (Hunan province, China) showed the highest mean concentration of V (543.91 mg/kg), posing high non-carcinogenic risks, with high hazard quotient (HQ) value of 1.29 for children. While, V values of sampled soils near V titanomagnetite, petroleum associated minerals and uvanite areas were lower than that near stone coal area, also with lower HQ values (<1.00). Within 60 h, the removal efficiency of V(V) reached 98.4% with farmland soils near uvanite area, suggesting feasibility of V bioremediation via indigenous microbes. Bacterial communities after long-term cultivation (240 d) with V(V) were dominated by native microbes able to tolerate or reduce the toxicity of V(V), such as Ruminococcaceae_incertae_sedis, Trichococcus and Comamonas. This work is helpful for calling attention to V pollution of farmland near various V ore mining areas and formulating effective strategies for V(V) contamination bioremediation.
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Affiliation(s)
- Liting Hao
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China; Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing Advanced Innovation Center for Future Urban Design, Beijing University of Civil Engineering and Architecture, Beijing, 100044, PR China
| | - Baogang Zhang
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China.
| | - Chuanping Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, PR China
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Zhongfang Lei
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Kazuya Shimizu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
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Lakaniemi AM, Douglas GB, Kaksonen AH. Engineering and kinetic aspects of bacterial uranium reduction for the remediation of uranium contaminated environments. JOURNAL OF HAZARDOUS MATERIALS 2019; 371:198-212. [PMID: 30851673 DOI: 10.1016/j.jhazmat.2019.02.074] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/29/2019] [Accepted: 02/20/2019] [Indexed: 06/09/2023]
Abstract
Biological reduction of soluble uranium from U(VI) to insoluble U(IV) coupled to the oxidation of an electron donor (hydrogen or organic compounds) is a potentially cost-efficient way to reduce the U concentrations in contaminated waters to below regulatory limits. A variety of microorganisms originating from both U contaminated and non-contaminated environments have demonstrated U(VI) reduction capacity under anaerobic conditions. Bioreduction of U(VI) is considered especially promising for in situ remediation, where the activity of indigenous microorganisms is stimulated by supplying a suitable electron donor to the subsurface to contain U contamination to a specific location in a sparingly soluble form. Less studied microbial biofilm-based bioreactors and bioelectrochemical systems have also shown potential for efficient U(VI) reduction to remove U from contaminated water streams. This review compares the advantages and challenges of U(VI)-reducing in situ remediation processes, bioreactors and bioelectrochemical systems. In addition, the current knowledge of U(VI) bioreduction mechanisms and factors affecting U(VI) reduction kinetics (e.g. pH, temperature, and the chemical composition of the contaminated water) are discussed, as both of these aspects are important in designing efficient remediation processes.
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Affiliation(s)
- Aino-Maija Lakaniemi
- Tampere University, Faculty of Engineering and Natural Sciences, P.O. Box 541, FI- 33104, Tampere University, Finland; CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia.
| | - Grant B Douglas
- CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water, 147 Underwood Avenue, Floreat, Western Australia, 6014, Australia
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Ontiveros-Valencia A, Zhou C, Ilhan ZE, de Saint Cyr LC, Krajmalnik-Brown R, Rittmann BE. Total electron acceptor loading and composition affect hexavalent uranium reduction and microbial community structure in a membrane biofilm reactor. WATER RESEARCH 2017; 125:341-349. [PMID: 28881210 DOI: 10.1016/j.watres.2017.08.060] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 08/26/2017] [Accepted: 08/28/2017] [Indexed: 06/07/2023]
Abstract
Molecular microbiology tools (i.e., 16S rDNA gene sequencing) were employed to elucidate changes in the microbial community structure according to the total electron acceptor loading (controlled by influent flow rate and/or medium composition) in a H2-based membrane biofilm reactor evaluated for removal of hexavalent uranium. Once nitrate, sulfate, and dissolved oxygen were replaced by U(VI) and bicarbonate and the total acceptor loading was lowered, slow-growing bacteria capable of reducing U(VI) to U(IV) dominated in the biofilm community: Replacing denitrifying bacteria Rhodocyclales and Burkholderiales were spore-producing Clostridiales and Natranaerobiales. Though potentially competing for electrons with U(VI) reducers, homo-acetogens helped attain steady U(VI) reduction, while methanogenesis inhibited U(VI) reduction. U(VI) reduction was reinstated through suppression of methanogenesis by addition of bromoethanesulfonate or by competition from SRB when sulfate was re-introduced. Predictive metagenome analysis further points out community changes in response to alterations in the electron-acceptor loading: Sporulation and homo-acetogenesis were critical factors for strengthening stable microbial U(VI) reduction. This study documents that sporulation was important to long-term U(VI) reduction, whether or not microorganisms that carry out U(VI) reduction mediated by cytochrome c3, such as SRB and ferric-iron-reducers, were inhibited.
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Affiliation(s)
- Aura Ontiveros-Valencia
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA; Escuela de Ingenieria y Ciencias, Tecnologico de Monterrey, Campus Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, NL 64849, Mexico; Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46617, USA
| | - Chen Zhou
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA.
| | - Zehra Esra Ilhan
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA
| | - Louis Cornette de Saint Cyr
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA; Institut Sup'Biotech de Paris, France
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 South McAllister Ave, Tempe, AZ 85287-5701, USA
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Cao X, Diao M, Zhang B, Liu H, Wang S, Yang M. Spatial distribution of vanadium and microbial community responses in surface soil of Panzhihua mining and smelting area, China. CHEMOSPHERE 2017; 183:9-17. [PMID: 28527917 DOI: 10.1016/j.chemosphere.2017.05.092] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/21/2017] [Accepted: 05/15/2017] [Indexed: 05/13/2023]
Abstract
Spatial distribution of vanadium in surface soils from different processing stages of vanadium-bearing titanomagnetite in Panzhihua mining and smelting area (China) as well as responses of microbial communities including bacteria and fungi to vanadium were investigated by fieldwork and laboratory incubation experiment. The vanadium contents in this region ranged from 149.3 to 4793.6 mg kg-1, exceeding the soil background value of vanadium in China (82 mg kg-1) largely. High-throughput DNA sequencing results showed bacterial communities from different manufacturing locations were quite diverse, but Bacteroidetes and Proteobacteria were abundant in all samples. The contents of organic matter, available P, available S and vanadium had great influences on the structures of bacterial communities in soils. Bacterial communities converged to similar structure after long-term (240 d) cultivation with vanadium containing medium, dominating by bacteria which can tolerate or reduce toxicities of heavy metals. Fungal diversities decreased after cultivation, but Ascomycota and Ciliophora were still the most abundant phyla as in the original soil samples. Results in this study emphasize the urgency of investigating vanadium contaminations in soils and provide valuable information on how vanadium contamination influences bacterial and fungal communities.
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Affiliation(s)
- Xuelong Cao
- School of Water Resources and Environment, China University of Geosciences Beijing, Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing, 100083, China
| | - Muhe Diao
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE, Amsterdam, The Netherlands
| | - Baogang Zhang
- School of Water Resources and Environment, China University of Geosciences Beijing, Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing, 100083, China.
| | - Hui Liu
- School of Water Resources and Environment, China University of Geosciences Beijing, Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing, 100083, China
| | - Song Wang
- School of Water Resources and Environment, China University of Geosciences Beijing, Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing, 100083, China
| | - Meng Yang
- School of Water Resources and Environment, China University of Geosciences Beijing, Key Laboratory of Groundwater Circulation and Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing, 100083, China
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The Role of Bacterial Spores in Metal Cycling and Their Potential Application in Metal Contaminant Bioremediation. Microbiol Spectr 2016; 4. [DOI: 10.1128/microbiolspec.tbs-0018-2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
ABSTRACT
Bacteria are one of the premier biological forces that, in combination with chemical and physical forces, drive metal availability in the environment. Bacterial spores, when found in the environment, are often considered to be dormant and metabolically inactive, in a resting state waiting for favorable conditions for them to germinate. However, this is a highly oversimplified view of spores in the environment. The surface of bacterial spores represents a potential site for chemical reactions to occur. Additionally, proteins in the outer layers (spore coats or exosporium) may also have more specific catalytic activity. As a consequence, bacterial spores can play a role in geochemical processes and may indeed find uses in various biotechnological applications. The aim of this review is to introduce the role of bacteria and bacterial spores in biogeochemical cycles and their potential use as toxic metal bioremediation agents.
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Transposon Mutagenesis Paired with Deep Sequencing of Caulobacter crescentus under Uranium Stress Reveals Genes Essential for Detoxification and Stress Tolerance. J Bacteriol 2015. [PMID: 26195598 DOI: 10.1128/jb.00382-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED The ubiquitous aquatic bacterium Caulobacter crescentus is highly resistant to uranium (U) and facilitates U biomineralization and thus holds promise as an agent of U bioremediation. To gain an understanding of how C. crescentus tolerates U, we employed transposon (Tn) mutagenesis paired with deep sequencing (Tn-seq) in a global screen for genomic elements required for U resistance. Of the 3,879 annotated genes in the C. crescentus genome, 37 were found to be specifically associated with fitness under U stress, 15 of which were subsequently tested through mutational analysis. Systematic deletion analysis revealed that mutants lacking outer membrane transporters (rsaFa and rsaFb), a stress-responsive transcription factor (cztR), or a ppGpp synthetase/hydrolase (spoT) exhibited a significantly lower survival rate under U stress. RsaFa and RsaFb, which are homologues of TolC in Escherichia coli, have previously been shown to mediate S-layer export. Transcriptional analysis revealed upregulation of rsaFa and rsaFb by 4- and 10-fold, respectively, in the presence of U. We additionally show that rsaFa mutants accumulated higher levels of U than the wild type, with no significant increase in oxidative stress levels. Our results suggest a function for RsaFa and RsaFb in U efflux and/or maintenance of membrane integrity during U stress. In addition, we present data implicating CztR and SpoT in resistance to U stress. Together, our findings reveal novel gene targets that are key to understanding the molecular mechanisms of U resistance in C. crescentus. IMPORTANCE Caulobacter crescentus is an aerobic bacterium that is highly resistant to uranium (U) and has great potential to be used in U bioremediation, but its mechanisms of U resistance are poorly understood. We conducted a Tn-seq screen to identify genes specifically required for U resistance in C. crescentus. The genes that we identified have previously remained elusive using other omics approaches and thus provide significant insight into the mechanisms of U resistance by C. crescentus. In particular, we show that outer membrane transporters RsaFa and RsaFb, previously known as part of the S-layer export machinery, may confer U resistance by U efflux and/or by maintaining membrane integrity during U stress.
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Toxic influence of silver and uranium salts on activated sludge of wastewater treatment plants and synthetic activated sludge associates modeled on its pure cultures. Bioprocess Biosyst Eng 2015; 38:125-35. [PMID: 25027236 DOI: 10.1007/s00449-014-1250-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 06/24/2014] [Indexed: 10/25/2022]
Abstract
Toxic impact of silver and uranium salts on activated sludge of wastewater treatment facilities has been studied. Some dominating cultures (an active nitrogen fixer Agrobacterium tumifaciens (A.t) and micromyces such as Fusarium nivale, Fusarium oxysporum, and Penicillium glabrum) have been isolated and identified as a result of selection of the activated sludge microorganisms being steadiest under stressful conditions. For these cultures, the lethal doses of silver amounted 1, 600, 50, and 300 µg/l and the lethal doses of uranium were 120, 1,500, 1,000, and 1,000 mg/l, respectively. A.tumifaciens is shown to be more sensitive to heavy metals than micromyces. Synthetic granular activated sludge was formed on the basis of three cultures of the isolated micromyces steadiest against stress. Its granules were much more resistant to silver than the whole native activated sludge was. The concentration of silver causing 50 % inhibition of synthetic granular activated sludge growth reached 160-170 μg/l as far as for the native activated sludge it came only to 100-110 μg/l.
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12
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Zhou C, Ontiveros-Valencia A, Cornette de Saint Cyr L, Zevin AS, Carey SE, Krajmalnik-Brown R, Rittmann BE. Uranium removal and microbial community in a H2-based membrane biofilm reactor. WATER RESEARCH 2014; 64:255-264. [PMID: 25073000 DOI: 10.1016/j.watres.2014.07.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 07/06/2014] [Accepted: 07/07/2014] [Indexed: 05/26/2023]
Abstract
We evaluated a hydrogen-based membrane biofilm reactor (MBfR) for its capacity to reduce and remove hexavalent uranium [U(VI)] from water. After a startup period that allowed slow-growing U(VI) reducers to form biofilms, the MBfR successfully achieved and maintained 94-95% U(VI) removal over 8 months when the U surface loading was 6-11 e(-) mEq/m(2)-day. The MBfR biofilm was capable of self-recovery after a disturbance due to oxygen exposure. Nanocrystalline UO2 aggregates and amorphous U precipitates were associated with vegetative cells and apparently mature spores that accumulated in the biofilm matrix. Despite inoculation with a concentrated suspension of Desulfovibrio vulgaris, this bacterium was not present in the U(VI)-reducing biofilm. Instead, the most abundant group in the biofilm community contained U(VI) reducers in the Rhodocyclaceae family when U(VI) was the only electron acceptor. When sulfate was present, the community dramatically shifted to the Clostridiaceae family, which included spores that were potentially involved in U(VI) reduction.
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Affiliation(s)
- Chen Zhou
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Aura Ontiveros-Valencia
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA.
| | - Louis Cornette de Saint Cyr
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA; Institut Sup'Biotech de Paris, France
| | - Alexander S Zevin
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Sara E Carey
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Rosa Krajmalnik-Brown
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
| | - Bruce E Rittmann
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, USA
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13
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Paraneeiswaran A, Shukla SK, Prashanth K, Rao TS. Microbial reduction of [Co(III)-EDTA]⁻ by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan. JOURNAL OF HAZARDOUS MATERIALS 2014; 283:582-590. [PMID: 25464299 DOI: 10.1016/j.jhazmat.2014.09.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 09/15/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)-EDTA](-) reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)-EDTA](-) generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)-EDTA](2-) is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1mM [Co(III)-EDTA](-) in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)-EDTA](-) acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)-EDTA](-) reduction. More detailed investigations showed that after [Co(III)-EDTA](-) reduction, i.e. [Co(II)-EDTA](2-) complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste.
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Affiliation(s)
| | - Sudhir K Shukla
- Biofouling & Biofilm Processes Section, Water & Steam Chemistry Division, BARC Facilities, Kalpakkam 603102, India; Homi Bhabha National Institute, Mumbai 400094, India
| | - K Prashanth
- Departartment of Biotechnology, Pondicherry University, Puducherry, India
| | - T Subba Rao
- Biofouling & Biofilm Processes Section, Water & Steam Chemistry Division, BARC Facilities, Kalpakkam 603102, India; Homi Bhabha National Institute, Mumbai 400094, India.
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14
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Abstract
ABSTRACT
Clostridia are Gram-positive, anaerobic, endospore-forming bacteria, incapable of dissimilatory sulfate reduction. Comprising approximately 180 species, the genus
Clostridium
is one of the largest bacterial genera. Physiology is mostly devoted to acid production. Numerous pathways are known, such as the homoacetate fermentation by acetogens, the propionate fermentation by
Clostridium propionicum
, and the butyrate/butanol fermentation by
C. acetobutylicum
, a well-known solvent producer. Clostridia degrade sugars, alcohols, amino acids, purines, pyrimidines, and polymers such as starch and cellulose. Energy conservation can be performed by substrate-level phosphorylation as well as by the generation of ion gradients. Endospore formation resembles the mechanism elucidated in
Bacillus
. Morphology, contents, and properties of spores are very similar to bacilli endospores. Sporulating clostridia usually form swollen mother cells and accumulate the storage substance granulose. However, clostridial sporulation differs by not employing the so-called phosphorelay. Initiation starts by direct phosphorylation of the master regulator Spo0A. The cascade of sporulation-specific sigma factors is again identical to what is known from
Bacillus
. The onset of sporulation is coupled in some species to either solvent (acetone, butanol) or toxin (e.g.,
C. perfringens
enterotoxin) formation. The germination of spores is often induced by various amino acids, often in combination with phosphate and sodium ions. In medical applications,
C. butyricum
spores are used as a
C. difficile
prophylaxis and as treatment against diarrhea. Recombinant spores are currently under investigation and testing as antitumor agents, because they germinate only in hypoxic tissues (i.e., tumor tissue), allowing precise targeting and direct killing of tumor cells.
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15
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Natrajan LS, Swinburne AN, Andrews MB, Randall S, Heath SL. Redox and environmentally relevant aspects of actinide(IV) coordination chemistry. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.12.021] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Bioremediation of uranium-contaminated groundwater: a systems approach to subsurface biogeochemistry. Curr Opin Biotechnol 2013; 24:489-97. [DOI: 10.1016/j.copbio.2012.10.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 10/09/2012] [Indexed: 11/18/2022]
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17
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Latta DE, Pearce CI, Rosso KM, Kemner KM, Boyanov MI. Reaction of U(VI) with titanium-substituted magnetite: influence of Ti on U(IV) speciation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4121-4130. [PMID: 23597442 DOI: 10.1021/es303383n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Reduction of hexavalent uranium (U(VI)) to less soluble tetravalent uranium (U(IV)) through enzymatic or abiotic redox reactions has the potential to alter U mobility in subsurface environments. As a ubiquitous natural mineral, magnetite (Fe3O4) is of interest because of its ability to act as a rechargeable reductant for U(VI). Natural magnetites are often impure with titanium, and structural Fe(3+) replacement by Ti(IV) yields a proportional increase in the relative Fe(2+) content in the metal sublattice to maintain bulk charge neutrality. In the absence of oxidation, the Ti content sets the initial bulk Fe(2+)/Fe(3+) ratio (R). Here, we demonstrate that Ti-doped magnetites (Fe3 - xTixO4) reduce U(VI) to U(IV). The U(VI)-Fe(2+) redox reactivity was found to be controlled directly by R but was otherwise independent of Ti content (xTi). However, in contrast to previous studies with pure magnetite where U(VI) was reduced to nanocrystalline uraninite (UO2), the presence of structural Ti (xTi = 0.25-0.53) results in the formation of U(IV) species that lack the bidentate U-O2-U bridges of uraninite. Extended X-ray absorption fine structure spectroscopic analysis indicated that the titanomagnetite-bound U(IV) phase has a novel U(IV)-Ti binding geometry different from the coordination of U(IV) in the mineral brannerite (U(IV)Ti2O6). The observed U(IV)-Ti coordination at a distance of 3.43 Å suggests a binuclear corner-sharing adsorption/incorporation U(IV) complex with the solid phase. Furthermore, we explored the effect of oxidation (decreasing R) and solids-to-solution ratio on the reduced U(IV) phase. The formation of the non-uraninite U(IV)-Ti phase appears to be controlled by availability of surface Ti sites rather than R. Our work highlights a previously unrecognized role of Ti in the environmental chemistry of U(IV) and suggests that further work to characterize the long-term stability of U(IV) phases formed in the presence of Ti is warranted.
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Affiliation(s)
- Drew E Latta
- Biosciences Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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18
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Gao W, Francis AJ. Fermentation and hydrogen metabolism affect uranium reduction by clostridia. ISRN BIOTECHNOLOGY 2013; 2013:657160. [PMID: 25937978 PMCID: PMC4393052 DOI: 10.5402/2013/657160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 01/19/2013] [Indexed: 11/23/2022]
Abstract
Previously, it has been shown that not only is uranium reduction under fermentation condition common among clostridia species, but also the strains differed in the extent of their capability and the pH of the culture significantly affected uranium(VI) reduction. In this study, using HPLC and GC techniques, metabolic properties of those clostridial strains active in uranium reduction under fermentation conditions have been characterized and their effects on capability variance of uranium reduction discussed. Then, the relationship between hydrogen metabolism and uranium reduction has been further explored and the important role played by hydrogenase in uranium(VI) and iron(III) reduction by clostridia demonstrated. When hydrogen was provided as the headspace gas, uranium(VI) reduction occurred in the presence of whole cells of clostridia. This is in contrast to that of nitrogen as the headspace gas. Without clostridia cells, hydrogen alone could not result in uranium(VI) reduction. In alignment with this observation, it was also found that either copper(II) addition or iron depletion in the medium could compromise uranium reduction by clostridia. In the end, a comprehensive model was proposed to explain uranium reduction by clostridia and its relationship to the overall metabolism especially hydrogen (H2) production.
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Affiliation(s)
- Weimin Gao
- Center for Biosignatures Discovery Automation, Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Arokiasamy J. Francis
- Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
- Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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19
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Kushwaha S, Sreedhar B, Padmaja P. XPS, EXAFS, and FTIR as tools to probe the unexpected adsorption-coupled reduction of U(VI) to U(V) and U(IV) on Borassus flabellifer-based adsorbents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:16038-16048. [PMID: 23088351 DOI: 10.1021/la3013443] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Palm shell-based adsorbents prepared under five different thermochemical conditions and palm shell powder have been shown to be quite effective for removal of uranium from aqueous solutions. X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and Fourier transform infrared spectroscopy (FTIR) have been used to determine information about the speciation and binding of uranium on the adsorbents under study. Studies indicate that the uranium which is present as uranyl ion in aqueous solution is present in mixed valence states (U(IV), U(V), and U(VI)) when it is bound to the adsorbents. The mechanism of adsorption is likely to be adsorption-coupled reduction as well as complexation. Adsorption of uranium, cesium, and iron was found to be quantitative in binary as well as ternary mixtures.
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Affiliation(s)
- S Kushwaha
- Department of Chemistry, Faculty of Science, The M S University of Baroda, Vadodara, India
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20
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Ahmed B, Cao B, Mishra B, Boyanov MI, Kemner KM, Fredrickson JK, Beyenal H. Immobilization of U(VI) from oxic groundwater by Hanford 300 Area sediments and effects of Columbia River water. WATER RESEARCH 2012; 46:3989-3998. [PMID: 22683408 DOI: 10.1016/j.watres.2012.05.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 05/08/2012] [Accepted: 05/15/2012] [Indexed: 06/01/2023]
Abstract
Regions within the U.S. Department of Energy Hanford 300 Area (300 A) site experience periodic hydrologic influences from the nearby Columbia River as a result of changing river stage, which causes changes in groundwater elevation, flow direction and water chemistry. An important question is the extent to which the mixing of Columbia River water and groundwater impacts the speciation and mobility of uranium (U). In this study, we designed experiments to mimic interactions among U, oxic groundwater or Columbia River water, and 300 A sediments in the subsurface environment of Hanford 300 A. The goals were to investigate mechanisms of: 1) U immobilization in 300 A sediments under bulk oxic conditions and 2) U remobilization from U-immobilized 300 A sediments exposed to oxic Columbia River water. Initially, 300 A sediments in column reactors were fed with U(VI)-containing oxic 1) synthetic groundwater (SGW), 2) organic-amended SGW (OA-SGW), and 3) de-ionized (DI) water to investigate U immobilization processes. After that, the sediments were exposed to oxic Columbia River water for U remobilization studies. The results reveal that U was immobilized by 300 A sediments predominantly through reduction (80-85%) when the column reactor was fed with oxic OA-SGW. However, U was immobilized by 300 A sediments through adsorption (100%) when the column reactors were fed with oxic SGW or DI water. The reduced U in the 300 A sediments fed with OA-SGW was relatively resistant to remobilization by oxic Columbia River water. Oxic Columbia River water resulted in U remobilization (∼7%) through desorption, and most of the U that remained in the 300 A sediments fed with OA-SGW (∼93%) was in the form of uraninite nanoparticles. These results reveal that: 1) the reductive immobilization of U through OA-SGW stimulation of indigenous 300 A sediment microorganisms may be viable in the relatively oxic Hanford 300 A subsurface environments and 2) with the intrusion of Columbia River water, desorption may be the primary process resulting in U remobilization from OA-SGW-stimulated 300 A sediments at the subsurface of the Hanford 300 A site.
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Affiliation(s)
- Bulbul Ahmed
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Spokane St, PO Box 642710, Pullman, WA 99164-2710, United States
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21
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Assunção A, Martins M, Silva G, Lucas H, Coelho MR, Costa MC. Bromate removal by anaerobic bacterial community: mechanism and phylogenetic characterization. JOURNAL OF HAZARDOUS MATERIALS 2011; 197:237-243. [PMID: 21982540 DOI: 10.1016/j.jhazmat.2011.09.076] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 09/19/2011] [Accepted: 09/21/2011] [Indexed: 05/31/2023]
Abstract
A highly bromate resistant bacterial community and with ability for bromate removal was obtained from a sulphate-reducing bacteria enrichment consortium. This community was able to remove 96% of bromate and 99% of sulphate from an aqueous solution containing 40 μM bromate and 10 mM sulphate. Moreover, 93% of bromate was removed in the absence of sulphate. Under this condition bromate was reduced stoichiometrically to bromide. However, in the presence of sulphate only 88% of bromate was reduced to bromide. Although, bromate removal was not affected by the absence of sulphate, this anion promoted a modification on the structure of the bacterial community. Phylogenetic analysis of 16S rRNA gene showed that the community grown in the presence of bromate and sulphate was mainly composed by bacteria closely to Clostridium and Citrobacter genera, while the community grown in the absence of sulphate was predominantly composed by Clostridium genus. It is the first time that Clostridium and Citrobacter genera are reported as having bromate removal ability. Furthermore, bromate removal by the consortium predominantly composed by Clostridium and Citrobacter genera occurred by enzymatic reduction and by extracellular metabolic products, while the enzymatic process was the only mechanism involved in bromate removal by the consortium mainly composed by Clostridium genus.
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Affiliation(s)
- Ana Assunção
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, Faculdade de Ciências e de Tecnologia, Departamento de Química e Farmácia, Faro, Portugal.
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