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Gorbunov MV, Doert T, Mikhailova D. Na 2Fe 2Se 2O: a double anti-perovskite with prevalence of anionic redox activity in Na-ion batteries. Chem Commun (Camb) 2023; 59:13763-13766. [PMID: 37920906 DOI: 10.1039/d3cc04722a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Na2Fe2Se2O with the I4/mmm space group was studied in sodium-ion batteries, delivering a reversible specific capacity of more than 140 mA h g-1. Operando XRD and XAS studies disclosed bifunctional redox behaviour with the prevalence of anionic electrochemical activity and a likely partial decomposition of the material, which, however, does not influence the electrochemical behaviour of the system.
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Affiliation(s)
- Mikhail V Gorbunov
- Institute for Materials Chemistry, IFW Dresden, Helmholtzstraße 20, 01069, Dresden, Germany.
| | - Thomas Doert
- Faculty of Chemistry and Food Chemistry, TUD Dresden University of Technology, Helmholtzstr. 10, 01069, Dresden, Germany
| | - Daria Mikhailova
- Institute for Materials Chemistry, IFW Dresden, Helmholtzstraße 20, 01069, Dresden, Germany.
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2
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Ma X, Yang Z, Yu T, Guan DX. Probability of cultivating Se-rich maize in Se-poor farmland based on intensive field sampling and artificial neural network modelling. CHEMOSPHERE 2022; 309:136690. [PMID: 36202379 DOI: 10.1016/j.chemosphere.2022.136690] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 09/06/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Selenium (Se) is a necessary micronutrient for humans, and its supplementation from crop grains is important to address the ubiquitous Se deficiency in people worldwide. Se uptake by crops largely depend on soil bioavailable Se rather than soil total Se content, which provides possibilities to explore the Se-rich crops in Se-poor area. Here, the possibility of cultivating Se-rich maize grains in Se-poor farmland was tested based on intensive field sampling and mathematical modelling. Sampling was conducted at county scale, and a total of 7779 topsoil samples and 109 maize samples with paired rhizosphere soils samples were collected. Results showed that although the soil Se content in the study county from southwestern China was at a low level (0.01-2.75 mg kg-1), 54.1% of the maize grain samples satisfied the standard for Se-rich products (0.02-0.30 mg kg-1). Soil organic matter, iron oxide, and phosphorus levels were correlated negatively with Se bioconcentration factor (BCF) of maize grain. Compared with the multivariate linear regression model, the artificial neural network (ANN) model was more accurate and reliable in predicting maize Se BCF. Prediction using the ANN model showed that 22.7% of the county's farmland was suitable for cultivating naturally Se-rich maize, which increased 21.3% growing areas than that from cultivation based on simply soil total Se. This study provided a new methodological framework for natural Se-rich maize production and verified the probability of cultivating naturally Se-rich maize in Se-poor farmland.
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Affiliation(s)
- Xudong Ma
- School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Zhongfang Yang
- School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China; Key Laboratory of Ecological Geochemistry, Ministry of Natural Resources, Beijing 100037, PR China.
| | - Tao Yu
- School of Science, China University of Geosciences, Beijing 100083, PR China; Key Laboratory of Ecological Geochemistry, Ministry of Natural Resources, Beijing 100037, PR China
| | - Dong-Xing Guan
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, PR China
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3
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Favorito JE, Grossl PR, Davis TZ, Eick MJ, Hankes N. Soil-plant-animal relationships and geochemistry of selenium in the Western Phosphate Resource Area (United States): A review. CHEMOSPHERE 2021; 266:128959. [PMID: 33279237 DOI: 10.1016/j.chemosphere.2020.128959] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
While naturally found in trace quantities, several regions throughout the world have been designated as "seleniferous" or containing an overabundance of the trace element, selenium (Se), in soil. In particular, portions of the Western Phosphate Resource Area (WPRA) of the United States are considered seleniferous, notably due to past phosphate mining reclamation practices that have promoted Se release and accumulation in soil from weathering overburden waste rock. Concern over Se soil contamination in this region has been attributed to its high levels (ranging from 2.7 to 435 mg Se kg-1 soil), bioavailability, and subsequent hyperaccumulation in vegetation at toxic concentrations (exceeding 10,000 mg Se kg-1 plant tissue). The Se hyperaccumulator, western aster (Symphyotrichum ascendens (Lindl.)), is responsible for the vast majority of acute selenium livestock poisonings and fatalities throughout the region. This inherent bioavailability is largely controlled by soil redox chemistry and sorptive processes. The purpose of this review is to integrate information related to the unique site history of the WPRA from onset mining to current Se problems. This review will provide current details and connection of WPRA mining geology, soil Se geochemistry, plant hyperaccumulation, and related livestock fatalities. Soil remediation strategies will also be discussed along with their applicability and viability in this particular anthropogenically-influenced seleniferous region.
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Affiliation(s)
- Jessica E Favorito
- Environmental Science Program, 101 Vera King Farris Dr., Stockton University, Galloway, NJ, 08205, USA.
| | - Paul R Grossl
- Department of Plants, Soils, and Climate, 4820 Old Main Hill, Utah State University, Logan, UT, 84322, USA.
| | - Thomas Zane Davis
- USDA-ARS Poisonous Plant Research, 1150 East 1400 North, Logan, UT, 84341, USA.
| | - Matthew J Eick
- Department of Crop and Soil Environmental Sciences, 185 Ag Quad Ln, 237 Smyth Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
| | - Nathan Hankes
- Department of Plants, Soils, and Climate, 4820 Old Main Hill, Utah State University, Logan, UT, 84322, USA.
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Qin HB, Zhu JM, Tan D, Xu WP, Liang DX, Takahashi Y. Microscale Investigation into Selenium Distribution and Speciation in Se-Rich Soils from Enshi, China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 106:40-43. [PMID: 33452893 DOI: 10.1007/s00128-020-03090-7] [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: 10/31/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
In this study, we investigated the distribution and chemical speciation of Se in Se-rich soil by using micro-focused X-ray absorption near-edge structure (μ-XANES) spectroscopy coupling with X-ray fluorescence (μ-XRF) mapping. The microscale distribution showed that Se is heterogeneously distributed in the soil from seleniferous areas in Enshi, China. Se K-edge μ-XANES analysis suggested that Se is mainly present as Se(IV), organic Se(-II) or Se(0) species in Se-rich agricultural soil. The findings from this study would help improve the understanding of the fate, mobility, bioavailability, and biogeochemical cycling of Se in the seleniferous soil environment.
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Affiliation(s)
- Hai-Bo Qin
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Jian-Ming Zhu
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, 100083, China
| | - Decan Tan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Wen-Po Xu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Dong-Xu Liang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Yoshio Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan
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5
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Kinetic and mechanistic studies of the first step of the reaction between thiols and selenite. REACTION KINETICS MECHANISMS AND CATALYSIS 2020. [DOI: 10.1007/s11144-020-01877-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Xu Y, Hao Z, Li Y, Li H, Wang L, Zang Z, Liao X, Zhang R. Distribution of selenium and zinc in soil-crop system and their relationship with environmental factors. CHEMOSPHERE 2020; 242:125289. [PMID: 31896204 DOI: 10.1016/j.chemosphere.2019.125289] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/28/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
Selenium (Se) and zinc (Zn) are essential microelements for humans with crucial biological functions. In this study, we determined Se and Zn concentrations in soils and rice grains on Hainan Island and investigated how their spatial distributions are related to soil mineral elements, topography, and vegetation coverage. Overall, the concentrations of Se and Zn in soils were higher than the background values for Chinese soil; the Se concentrations in rice grains were higher than the threshold value for Se deficiency in grains, but Zn concentrations were lower than the proposed critical concentration. Both Spearman's correlation and stepwise regression analysis showed that the concentrations of soil Fe and Ca significantly affected soil Se and Zn: a difference of 1 g kg-1 in soil Fe changed soil Se by 2.820 μg kg-1 and soil Zn by 0.785 mg kg-1, respectively, while a difference of 1 g kg-1 in soil Ca changed soil Se by 3.249 μg kg-1 and soil Zn by 0.356 mg kg-1, respectively. For rice grains, Se and Zn concentrations decreased with increasing elevation; every 100 m increase in elevation could decrease Se by 0.022 mg kg-1 and Zn by 0.912 mg kg-1. Moreover, the impact of Fe and Ca on soil Zn was relatively strong in the northeast region, while the influence of elevation on rice grain Se was more significant in the central region. The findings contribute to a better understanding of factors driving the distribution of Se and Zn in soils and crops.
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Affiliation(s)
- Yuefeng Xu
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhe Hao
- Key Laboratory of Engineering Oceanography, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing, 210093, China
| | - Yonghua Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Hairong Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li Wang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhenfeng Zang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoyong Liao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Ru Zhang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical 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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Persistent Bacterial and Fungal Community Shifts Exhibited in Selenium-Contaminated Reclaimed Mine Soils. Appl Environ Microbiol 2018; 84:AEM.01394-18. [PMID: 29915105 PMCID: PMC6070768 DOI: 10.1128/aem.01394-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 11/20/2022] Open
Abstract
Mining and other industrial activities worldwide have resulted in Se-enriched surface soils, which pose risks to human and environmental health. Although not well studied, microbial activity can alter Se bioavailability and distribution, even in oxic environments. We used high-throughput sequencing to profile bacterial and fungal communities inhabiting mine soils in southeastern Idaho, comparing mined and unmined locations within two reclaimed phosphate mine areas containing various Se concentrations. The goal was to determine whether microbial communities differed in (i) different mines, (ii) mined areas compared to unmined areas, and (iii) various soil Se concentrations. Though reclamation occurred 20 to 30 years ago, microbial community structures in mined soils were significantly altered compared to unmined soils, suggesting persistent mining-related impacts on soil processes. Additionally, operational taxonomic unit with a 97% sequence similarity cutoff (OTU0.03) richness and diversity were significantly diminished with increasing Se, though not with other geochemical parameters, suggesting that Se contamination shapes communities in favor of Se-tolerant microorganisms. Two bacterial phyla, Actinobacteria and Gemmatimonadetes, were enriched in high-Se soils, while for fungi, Ascomycota dominated all soils regardless of Se concentration. Combining diversity analyses and taxonomic patterns enables us to move toward connecting physiological function of microbial groups to Se biogeochemical cycling in oxic soil environments.IMPORTANCE Selenium contamination in natural environments is of great concern globally, and microbial processes are known to mediate Se transformations. Such transformations alter Se mobility, bioavailability, and toxicity, which can amplify or mitigate Se pollution. To date, nearly all studies investigating Se-microbe interactions have used culture-based approaches with anaerobic bacteria despite growing knowledge that (i) aerobic Se transformations can occur, (ii) such transformations can be mediated by microorganisms other than bacteria, and (iii) microbial community dynamics, rather than individual organismal activities, are important for metal(loid) cycling in natural environments. We examined bacterial and fungal communities in Se-contaminated reclaimed mine soils and found significant declines in diversity at high Se concentrations. Additionally, we identified specific taxonomic groups that tolerate excess Se and may be useful for bioremediation purposes. These patterns were similar across mines of different ages, suggesting that microbial community impacts may persist long after physicochemical parameters indicate complete site recovery.
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Fakra SC, Luef B, Castelle CJ, Mullin SW, Williams KH, Marcus MA, Schichnes D, Banfield JF. Correlative Cryogenic Spectromicroscopy to Investigate Selenium Bioreduction Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:503-512. [PMID: 26371540 DOI: 10.1021/acs.est.5b01409] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Accurate mapping of the composition and structure of minerals and associated biological materials is critical in geomicrobiology and environmental research. Here, we have developed an apparatus that allows the correlation of cryogenic transmission electron microscopy (cryo-TEM) and synchrotron hard X-ray microprobe (SHXM) data sets to precisely determine the distribution, valence state, and structure of selenium in biofilms sampled from a contaminated aquifer near Rifle, CO. Results were replicated in the laboratory via anaerobic selenate-reducing enrichment cultures. 16S rRNA analyses of field-derived biofilm indicated the dominance of Betaproteobacteria from the Comamonadaceae family and uncultivated members of the Simplicispira genus. The major product in field and culture-derived biofilms is ∼25-300 nm red amorphous Se0 aggregates of colloidal nanoparticles. Correlative analyses of the cultures provided direct evidence for the microbial dissimilatory reduction of Se(VI) to Se(IV) to Se0. Extended X-ray absorption fine-structure spectroscopy showed red amorphous Se0 with a first shell Se-Se interatomic distance of 2.339 ± 0.003 Å. Complementary scanning transmission X-ray microscopy revealed that these aggregates are strongly associated with a protein-rich biofilm matrix. These findings have important implications for predicting the stability and mobility of Se bioremediation products and understanding of Se biogeochemical cycling. The approach, involving the correlation of cryo-SHXM and cryo-TEM data sets from the same specimen area, is broadly applicable to biological and environmental samples.
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Affiliation(s)
- Sirine C Fakra
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Birgit Luef
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Cindy J Castelle
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Sean W Mullin
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Kenneth H Williams
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Matthew A Marcus
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Denise Schichnes
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
| | - Jillian F Banfield
- Department of Earth and Planetary Science and ‡Department of Plant & Microbial Biology, University of California , Berkeley, California 94720, United States
- Advanced Light Source and ∥Earth Sciences Division, Lawrence Berkeley National Lab , Berkeley, California 94720, United States
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Liang R, Song S, Shi Y, Shi Y, Lu Y, Zheng X, Xu X, Wang Y, Han X. Comprehensive assessment of regional selenium resources in soils based on the analytic hierarchy process: Assessment system construction and case demonstration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 605-606:618-625. [PMID: 28672250 DOI: 10.1016/j.scitotenv.2017.06.150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/19/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
The redundancy or deficiency of selenium in soils can cause adverse effects on crops and even threaten human health. It was necessary to assess selenium resources with a rigorous scientific appraisal. Previous studies of selenium resource assessment were usually carried out using a single index evaluation. A multi-index evaluation method (analytic hierarchy process) was used in this study to establish a comprehensive assessment system based on consideration of selenium content, soil nutrients and soil environmental quality. The criteria for the comprehensive assessment system were classified by summing critical values in the standards with weights and a Geographical Information System was used to reflect the regional distribution of the assessment results. Boshan, a representative region for developing selenium-rich agriculture, was taken as a case area and classified into Zone I-V, which suggested priority areas for developing selenium-rich agriculture. Most parts of the North and Midlands of Boshan were relatively suitable for development of selenium-rich agriculture. Soils in south fractions were contaminated by Cd, PAHs, HCHs and DDTs, in which it was forbidden to farm. This study was expected to provide the basis for developing selenium-rich agriculture and an example for comprehensive evaluation of relevant resources in a region.
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Affiliation(s)
- Ruoyu Liang
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuai Song
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yajing Shi
- School of Biomedical and Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China
| | - Yajuan Shi
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Yonglong Lu
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoqi Zheng
- School of Environment & Natural Resources, Renmin University of China, Beijing, 100059, China
| | - Xiangbo Xu
- School of Environment & Natural Resources, Renmin University of China, Beijing, 100059, China
| | - Yurong Wang
- School of Biomedical and Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China
| | - Xuesong Han
- School of Biomedical and Chemical Engineering, Liaoning Institute of Science and Technology, Benxi 117004, China
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10
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Kopittke PM, Wang P, Lombi E, Donner E. Synchrotron-based X-Ray Approaches for Examining Toxic Trace Metal(loid)s in Soil-Plant Systems. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:1175-1189. [PMID: 29293828 DOI: 10.2134/jeq2016.09.0361] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Elevated levels of trace metal(loid)s reduce plant growth, both in soils contaminated by industrial activities and in acid agricultural soils. Although the adverse effects of trace metal(loid)s have long been recognized, there remains much unknown both about their behavior in soils, their toxicity to plants, and the mechanisms that plants use to tolerate elevated concentrations. Synchrotron-based approaches are being utilized increasingly in soil-plant systems to examine toxic metal(loid)s. In the present review, brief consideration is given to the theory of synchrotron radiation. Thereafter, we review the use of synchrotron-based approaches for the examination of various trace metal(loid)s in soil-plant systems, including aluminum, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, and cadmium. Within the context of this review, X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (μ-XRF) are of particular interest. These techniques can provide in situ analyses of the distribution and speciation of metal(loid)s in soil-plant systems. The information presented here serves not only to understand the behavior of trace metals in soil-plant systems, but also to provide examples of the potential applications of synchrotron radiation that can be used to advantage in other studies.
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Favorito JE, Luxton TP, Eick MJ, Grossl PR. Selenium speciation in phosphate mine soils and evaluation of a sequential extraction procedure using XAFS. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 229:911-921. [PMID: 28781183 PMCID: PMC7363211 DOI: 10.1016/j.envpol.2017.07.071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/17/2017] [Accepted: 07/22/2017] [Indexed: 05/20/2023]
Abstract
Selenium is a trace element found in western US soils, where ingestion of Se-accumulating plants has resulted in livestock fatalities. Therefore, a reliable understanding of Se speciation and bioavailability is critical for effective mitigation. Sequential extraction procedures (SEP) are often employed to examine Se phases and speciation in contaminated soils but may be limited by experimental conditions. We examined the validity of a SEP using X-ray absorption spectroscopy (XAS) for both whole and a sequence of extracted soils. The sequence included removal of soluble, PO4-extractable, carbonate, amorphous Fe-oxide, crystalline Fe-oxide, organic, and residual Se forms. For whole soils, XANES analyses indicated Se(0) and Se(-II) predominated, with lower amounts of Se(IV) present, related to carbonates and Fe-oxides. Oxidized Se species were more elevated and residual/elemental Se was lower than previous SEP results from ICP-AES suggested. For soils from the SEP sequence, XANES results indicated only partial recovery of carbonate, Fe-oxide and organic Se. This suggests Se was incompletely removed during designated extractions, possibly due to lack of mineral solubilization or reagent specificity. Selenium fractions associated with Fe-oxides were reduced in amount or removed after using hydroxylamine HCl for most soils examined. XANES results indicate partial dissolution of solid-phases may occur during extraction processes. This study demonstrates why precautions should be taken to improve the validity of SEPs. Mineralogical and chemical characterizations should be completed prior to SEP implementation to identify extractable phases or mineral components that may influence extraction effectiveness. Sequential extraction procedures can be appropriately tailored for reliable quantification of speciation in contaminated soils.
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Affiliation(s)
- Jessica E Favorito
- Department of Crop and Soil Environmental Sciences, 185 Ag Quad Lane, 237 Smyth Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
| | - Todd P Luxton
- United States Environmental Protection Agency, National Risk Management Research Laboratory Land Remediation and Pollution Control Division, 5995 Center Hill Avenue, Cincinnati, OH 45243, USA.
| | - Matthew J Eick
- Department of Crop and Soil Environmental Sciences, 185 Ag Quad Lane, 237 Smyth Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
| | - Paul R Grossl
- Department of Plants, Soils, and Climate, 4820 Old Main Hill, Utah State University, Logan, UT 84322, USA.
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12
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Qin HB, Takeichi Y, Nitani H, Terada Y, Takahashi Y. Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6027-6035. [PMID: 28426210 DOI: 10.1021/acs.est.7b00955] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocused X-ray fluorescence (μ-XRF), X-ray diffraction (μ-XRD), and X-ray absorption fine structure (μ-XAFS) techniques. Results showed that Te was present as a mixture of Te(VI) and Te(IV) species, while selenium (Se) was predominantly present in the form of Se(IV) in the soil contaminated by abandoned mine tailings. In the contaminated soil, Fe(III) hydroxides were the host phases for Se(IV), Te(IV), and Te(VI), but Te(IV) could be also retained by illite. The difference in speciation and solubility of Se and Te in soil can result from different structures of surface complexes for Se and Te onto Fe(III) hydroxides. Furthermore, our results suggest that the retention of Te(IV) in soil could be relatively weaker than that of Te(VI) due to structural incorporation of Te(VI) into Fe(III) hydroxides. These findings are of geochemical and environmental significance for better understanding the solubility, mobility, and bioavailability of Te in the surface environment. To the best of our knowledge, this is the first study reporting the speciation and host phases of Te in field soil by the μ-XRF-XRD-XAFS techniques.
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Affiliation(s)
- Hai-Bo Qin
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences , Guiyang 550081, China
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo , Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuo Takeichi
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) , 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Hiroaki Nitani
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) , 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Yasuko Terada
- Japan Synchrotron Radiation Research Institute (JASRI), SPring-8 , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Yoshio Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo , Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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Qin HB, Zhu JM, Lin ZQ, Xu WP, Tan DC, Zheng LR, Takahashi Y. Selenium speciation in seleniferous agricultural soils under different cropping systems using sequential extraction and X-ray absorption spectroscopy. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 225:361-369. [PMID: 28314620 DOI: 10.1016/j.envpol.2017.02.062] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 06/06/2023]
Abstract
Selenium (Se) speciation in soil is critically important for understanding the solubility, mobility, bioavailability, and toxicity of Se in the environment. In this study, Se fractionation and chemical speciation in agricultural soils from seleniferous areas were investigated using the elaborate sequential extraction and X-ray absorption near-edge structure (XANES) spectroscopy. The speciation results quantified by XANES technique generally agreed with those obtained by sequential extraction, and the combination of both approaches can reliably characterize Se speciation in soils. Results showed that dominant organic Se (56-81% of the total Se) and lesser Se(IV) (19-44%) were observed in seleniferous agricultural soils. A significant decrease in the proportion of organic Se to the total Se was found in different types of soil, i.e., paddy soil (81%) > uncultivated soil (69-73%) > upland soil (56-63%), while that of Se(IV) presented an inverse tendency. This suggests that Se speciation in agricultural soils can be significantly influenced by different cropping systems. Organic Se in seleniferous agricultural soils was probably derived from plant litter, which provides a significant insight for phytoremediation in Se-laden ecosystems and biofortification in Se-deficient areas. Furthermore, elevated organic Se in soils could result in higher Se accumulation in crops and further potential chronic Se toxicity to local residents in seleniferous areas.
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Affiliation(s)
- Hai-Bo Qin
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Jian-Ming Zhu
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China.
| | - Zhi-Qing Lin
- Environmental Sciences Program and Department of Biological Sciences, Southern Illinois University, Edwardsville, IL 62026-1099, USA
| | - Wen-Po Xu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - De-Can Tan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li-Rong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Yoshio Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
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14
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Wang Y, Wang Y, Zhang L, Chen L, Liu Z, Yin X, Sheng D, Diwu J, Wang J, Liu N, Chai Z, Wang S. Substitutional Disorder of SeO32–/IO3– in the Crystalline Solid Matrix: Insights into the Fate of Radionuclides 79Se and 129I in the Environment. Inorg Chem 2017; 56:3702-3708. [DOI: 10.1021/acs.inorgchem.7b00236] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yaxing Wang
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
- Key Laboratory
of Radiation Physics and Technology, Ministry of Education, Institute
of Nuclear Science and Technology, Sichuan University, Chengdu 610064, P. R. China
| | - Yumin Wang
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Linjuan Zhang
- Shanghai
Institute of Applied Physics and Key Laboratory of Nuclear Radiation
and Nuclear Energy Technology, Chinese Academy of Sciences, 201800 Shanghai, P. R. China
| | - Lanhua Chen
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Zhiyong Liu
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Xuemiao Yin
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Daopeng Sheng
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Juan Diwu
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Jianqiang Wang
- Shanghai
Institute of Applied Physics and Key Laboratory of Nuclear Radiation
and Nuclear Energy Technology, Chinese Academy of Sciences, 201800 Shanghai, P. R. China
| | - Ning Liu
- Key Laboratory
of Radiation Physics and Technology, Ministry of Education, Institute
of Nuclear Science and Technology, Sichuan University, Chengdu 610064, P. R. China
| | - Zhifang Chai
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
| | - Shuao Wang
- School for Radiological
and Interdisciplinary Sciences (RAD-X), Soochow University, 215123 Suzhou, P. R. China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou, P. R. China
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15
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Galkaduwa MB, Hettiarachchi GM, Kluitenberg GJ, Hutchinson SL, Davis L, Erickson LE. Transport and Transformation of Selenium and Other Constituents of Flue-Gas Desulfurization Wastewater in Water-Saturated Soil Materials. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:384-392. [PMID: 28380560 DOI: 10.2134/jeq2016.09.0335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Constructed wetland treatment systems are used to remove selenium (Se) from flue-gas desulfurization (FGD) wastewater (WW). However, direct confirmation of the mechanism responsible for FGD WW Se retention in soil is lacking. A laboratory-based soil column study was performed to develop an evidence-based mechanism of Se retention and to study the behavior and the retention capacity of FGD WW constituents in water-saturated soil. A deoxygenated 1:1 mixture of FGD WW and raw water was delivered to the columns bottom-up at a flux of 1.68 cm d for 100 d. Some of the columns were flushed with the raw water at the same rate for an additional 100 d. Column effluent was analyzed for constituents of concern. Results showed a complete retention of FGD WW Se in the soil materials. Boron and fluorine were partially retained; however, sulfur, sodium, and chlorine retention was poor, agreeing with field observations. The FGD WW Se was retained in soil near the inlet end of the columns, indicating its limited mobility under reduced conditions. Sequential extraction procedure revealed that retained Se was mainly sequestered as stable/residual forms. Bulk- and micro-X-ray absorption near-edge structure spectroscopy confirmed that Se was mainly retained as reduced/stable species [Se(IV), organic Se, and Se(0)]. This study provides direct evidence for FGD WW Se retention in water-saturated soil via the transformation of oxidized Se into reduced/stable forms.
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16
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Wang J, Li H, Yang L, Li Y, Wei B, Yu J, Feng F. Distribution and translocation of selenium from soil to highland barley in the Tibetan Plateau Kashin-Beck disease area. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2017; 39:221-229. [PMID: 27071616 DOI: 10.1007/s10653-016-9823-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 03/31/2016] [Indexed: 06/05/2023]
Abstract
Kashin-Beck disease (KBD), which is still active and severe in the Tibetan Plateau, is considered to be a kind of selenium (Se)-deficient disease. Highland barley as the most popular staple food in the Tibetan Plateau is one of the dominant Se sources for local people. To improve Se levels in crops in the Tibetan Plateau KBD area, the distribution and translocation of Se from soil to highland barley in both non-KBD and KBD endemic areas were investigated. The results showed that Se levels in highland barley were too low to meet the minimum requirements of human for daily intake of Se. The total Se concentrations of highland barley fractions in KBD areas were lower than that in non-KBD areas (grain P = 0.238; straw P = 0.087; root P = 0.008). However, no significant difference was observed in corresponding cultivated soil Se between the two areas (P = 0.993). The calculation of Se transfer factors indicated that the restricting step for Se translocation was from soil to root. Water-soluble, exchangeable and fulvic acid-bound Se fractions in the soil are key species dominating in this transfer process, according to their significant correlations with root Se. Se transfer from soil to root significantly increases as the pH value of soil increases (P = 0.007), and soil organic matter content decreases (P = 0.019). The information obtained may have considerable significance for proposing effective agricultural measures to increase grain Se in KBD endemic areas.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
- Graduate University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Hairong Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
| | - Linsheng Yang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
| | - Yonghua Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Binggan Wei
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Jiangping Yu
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
| | - Fujian Feng
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
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17
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Eiche E. Microscale distribution and elemental associations of Se in seleniferous soils in Punjab, India. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:5425-5436. [PMID: 25342451 DOI: 10.1007/s11356-014-3660-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 09/24/2014] [Indexed: 06/04/2023]
Abstract
Several regions around the globe are known to have soils highly enriched in Se. Usually, bulk samples are analysed when characterizing enrichment and mobility of Se in seleniferous soils. In this study, Se concentration and distribution were determined along with other elements on a microscale level in seleniferous soils from Punjab, India, using synchrotron-based X-ray fluorescence (XRF) analysis. Additionally, the mineralogical and geochemical composition of bulk soil material was investigated. Sequential extractions were carried out to gain further insight into preferential Se associations. The objective of this study was to investigate the microscale geochemistry of seleniferous soils in order to be able to deduce information about Se host phases, to characterize the distribution, extent and origin of Se enrichment and to possibly reveal the relevant enrichment processes. Selenium concentrations in the soils vary considerably within tens of micrometers. Thirty times the bulk concentration, the highest Se enrichment was found to be 350 mg/kg. Results show that the primary origin of Se in these soils is probably not from weathering of bedrock or alluvium but rather from an external Se source, like Se-rich irrigation water. Secondary processes like in situ formation of mineral phases, adsorption or transformation to organic species finally lead to an immobilization and fixation of Se in the soils. In this context, reduction of Se oxyanions to elemental Se or to selenide as part of sulfides probably leads to the highest Se enrichment which, however, is mainly spatially confined. Lower Se enrichments are indicated to be due to (co-)precipitation with or adsorption to calcite. Therefore, this extremely heterogeneous distribution of Se must be controlled by small-scale differences in redox and solution chemistry which can develop in small soil structure like micropores or soil aggregates.
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Affiliation(s)
- Elisabeth Eiche
- Institute of Mineralogy and Geochemistry, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany,
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18
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Arroyo-de Dompablo ME, Fernández-González MA, Fernández-Díaz L. Computational investigation of the influence of tetrahedral oxoanions (sulphate, selenate and chromate) on the stability of calcium carbonate polymorphs. RSC Adv 2015. [DOI: 10.1039/c5ra08574h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The incorporation of tetrahedral AO42− (A = S, Se, Cr) groups substituting CO32− groups is energetically more feasible for vaterite, less so for calcite and very unfavourable for aragonite.
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Affiliation(s)
- M. E. Arroyo-de Dompablo
- Dpto. de Química Inorgánica
- Facultad de Ciencias Químicas
- Universidad Complutense de Madrid
- 28040-Madrid
- Spain
| | | | - L. Fernández-Díaz
- Departamento de Cristalografía y Mineralogía
- Universidad Complutense de Madrid
- 28040 Madrid
- Spain
- Instituto de Geociencias (IGEO), (CSIC, UCM)
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19
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El Mehdawi AF, Lindblom SD, Cappa JJ, Fakra SC, Pilon-Smits EAH. Do selenium hyperaccumulators affect selenium speciation in neighboring plants and soil? An X-Ray Microprobe Analysis. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2015; 17:753-65. [PMID: 26030363 DOI: 10.1080/15226514.2014.987374] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Neighbors of Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus were found earlier to have elevated Se levels. Here we investigate whether Se hyperaccumulators affect Se localization and speciation in surrounding soil and neighboring plants. X-ray fluorescence mapping and X-ray absorption near-edge structure spectroscopy were used to analyze Se localization and speciation in leaves of Artemisia ludoviciana, Symphyotrichum ericoides and Chenopodium album growing next to Se hyperaccumulators or non-accumulators at a seleniferous site. Regardless of neighbors, A. ludoviciana, S. ericoides and C. album accumulated predominantly (73-92%) reduced selenocompounds with XANES spectra similar to the C-Se-C compounds selenomethionine and methyl-selenocysteine. Preliminary data indicate that the largest Se fraction (65-75%), both in soil next to hyperaccumulator S. pinnata and next to nonaccumulator species was reduced Se with spectra similar to C-Se-C standards. These same C-Se-C forms are found in hyperaccumulators. Thus, hyperaccumulator litter may be a source of organic soil Se, but soil microorganisms may also contribute. These findings are relevant for phytoremediation and biofortification since organic Se is more readily accumulated by plants, and more effective for dietary Se supplementation.
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Affiliation(s)
- Ali F El Mehdawi
- a Biology Department , Colorado State University , Fort Collins , CO
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20
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Liu YT, Chen TY, Mackebee WG, Ruhl L, Vengosh A, Hsu-Kim H. Selenium speciation in coal ash spilled at the Tennessee Valley Authority Kingston site. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:14001-9. [PMID: 24266628 DOI: 10.1021/es4041557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Selenium (Se) in coal ash spills poses a threat to adjacent ecosystems because of its potential to mobilize and bioaccumulate in aquatic organisms. Given that the mobility and bioavailability of Se is controlled by its valence states, we aimed to define Se speciation in coal ash solids and examine the relationships between Se speciation and the magnitude of its mobilization from coal ash. We used coal ash samples from the Tennessee Valley Authority (TVA)-Kingston fossil plant and the site of a coal ash spill that occurred in 2008 in Tennessee. Results of X-ray absorption spectroscopic analyses showed that Se in coal ash samples was a mixture of elemental Se(0) and Se oxyanions. The amount of leachable Se increased with an increase of pH from 3 to 13. At the natural pH of coal ash samples (from pH 7.6 to 9.5), the leachable Se was comprised of Se oxyanions, mainly selenite. This was observed by both direct quantification of Se oxyanions in the leachate and the corresponding loss of Se oxyanions in the solid phase. At pH 12, however, the Se release appeared to derive from both desorption of Se oxyanions and oxidative dissolution of elemental Se(0). Our results indicate that Se oxyanions are the most labile species; however, the magnitude of Se mobilization will increase if the waste material is subjected to alkaline conditions.
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Affiliation(s)
- Yu-Ting Liu
- Department of Civil and Environmental Engineering, 121 Hudson Hall, Box 90287, Duke University , Durham, North Carolina 27708, United States
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21
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Betts AR, Chen N, Hamilton JG, Peak D. Rates and mechanisms of Zn2+ adsorption on a meat and bonemeal biochar. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:14350-14357. [PMID: 24228903 DOI: 10.1021/es4032198] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Biochars produced from meat and bonemeal (MBM) waste materials contain large amounts of calcium phosphate and are potentially useful sorbents for the remediation of metals. Because the reactivity of biochars depends strongly upon the conditions used in their production, the objective of this study was to evaluate the rates and mechanisms of Zn sorption onto a commercially supplied MBM biochar prior to its application in a field-scale revegetation project. Sorption experiments varying pH, time, and Zn concentration found that, above pH 6.1, Zn adsorbed to MBM biochar quickly (within 5 h) with a maximum adsorption capacity of 0.65 mmol Zn g(-1). Synchrotron-based Zn K-edge extended X-ray absorption fine structure spectroscopy was consistent with a tetrahedral Zn bound to phosphate groups in a monodentate inner-sphere surface complex for all conditions tested. With an acidification pretreatment and at more acidic pH, MBM biochar causes precipitation of a ZnPO4 phase. On the basis of these results, this MBM biochar has a high capacity to rapidly adsorb Zn in adsorption experiments and can be considered a promising sorbent for Zn remediation of contaminated soils.
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Affiliation(s)
- Aaron R Betts
- Oak Ridge Institute for Science and Education , U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
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22
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Wovkulich K, Mailloux BJ, Bostick BC, Dong H, Bishop ME, Chillrud SN. Use of Microfocused X-ray Techniques to Investigate the Mobilization of As by Oxalic Acid. GEOCHIMICA ET COSMOCHIMICA ACTA 2012; 91:254-270. [PMID: 23175572 PMCID: PMC3501129 DOI: 10.1016/j.gca.2012.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Improved linkages between aqueous phase transport and solid-phase reactions are needed to better predict and model transport of contaminants through the subsurface. Here we develop and apply a new method for measuring As mobilization in situ within soil columns that utilizes synchrotron-based X-ray fluorescence. By performing these measurements in situ during column transport experiments, we simultaneously monitor grain-scale solid phase reactions and column-scale transport. Arsenic may be effectively mobilized by oxalic acid but the geochemical and mineralogical factors that influence the rate and extent of mobilization are not well understood. Column experiments (~4 cm long × 0.635 cm ID) using As contaminated sediments from the Vineland Chemical Company Superfund site were performed on the laboratory bench as well as in the synchrotron beamline. Microfocused synchrotron X-ray fluorescence (μSXRF) maps for As and Fe were collected at the same location in the columns (<1 mm(2)) before and during treatment with 10 mM oxalic acid. The fraction of As and Fe removed by oxalic acid treatment was calculated from the change in flux-normalized counts for each pixel in the map images, and these data were used to calculate kinetic parameters over the studied area. Between 79% and 83% of the As was removed from the sediments by the oxalic acid treatment based on μSXRF data; these removal percentages agreed well with laboratory data based on column effluent (88-95%). Considerably less Fe was removed by oxalic acid treatment, 14-25% based on μSXRF counts, which is somewhat higher than the 7-9% calculated from laboratory column effluent concentrations. Microfocused X-ray absorption near edge spectroscopy (μXANES) on a subset of points indicates most of the Fe was oxidized and present as a mixture of goethite, hematite, and ferrihydrite on sand grain coatings. Treatment with oxalic acid led to subtle shifts in Fe (III) species following oxalic acid treatment, either removing ferrihydrite or transforming it to more stable oxides; however, Fe redox states were not impacted. Kinetics information extracted from μSXRF data compared favorably with rates of As removal from observed As breakthrough curves. The average pseudo-first order As removal rate constant was calculated to be 0.015 min(-1) ± 0.002 (± average standard error, N=400) based on changes in μSXRF counts over time. The spatial variation observed in the rate constant is likely a result of differences in the mineral substrate or As retention mechanism. Geochemical models created using the calculated As removal rate constants showed agreement with As breakthrough curves for both a small column (4.25 cm × 0.635 cm ID) and a larger column (23.5 cm × 4.2 cm ID), indicating that the processes studied using the microprobe are representative and often can be predictive of larger systems. While this work was used to understand the processes that regulate As release and transport, the methods developed here could be used to study a wide variety of reaction processes, including contaminant removal due to chemical treatment, mineral precipitation due to changing redox characteristics, and solid phase transformations.
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Affiliation(s)
- Karen Wovkulich
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, 10027, USA
- Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA
- Corresponding author
| | - Brian J. Mailloux
- Department of Environmental Sciences, Barnard College, New York, NY 10027, USA
| | | | - Hailiang Dong
- Department of Geology, Miami University, Oxford, OH, 45056, USA
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23
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Misra S, Peak D, Chen N, Hamilton C, Niyogi S. Tissue-specific accumulation and speciation of selenium in rainbow trout (Oncorhynchus mykiss) exposed to elevated dietary selenomethionine. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:560-5. [PMID: 22261037 DOI: 10.1016/j.cbpc.2012.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/25/2011] [Accepted: 01/05/2012] [Indexed: 11/28/2022]
Abstract
The toxicity of selenium in fish is influenced by its chemical speciation and the exposure route. In the natural environment, selenium exposure to fish occurs primarily in the form of selenomethionine in diet. Thus, the main objective of this study was to examine the tissue-specific selenium burden and speciation in fish exposed to elevated dietary selenomethionine. Rainbow trout (Oncorhynchus mykiss) were treated with dietary selenomethionine (40 μg g(-1) dry mass) for 2 weeks, and at the end of the exposure different tissue samples were collected to assess the tissue-specific distribution and speciation of selenium. We used synchrotron-based X-ray absorption near edge spectroscopy (XANES) to determine the selenium speciation profile. Selenomethionine, selenocysteine and selenocystine were found to be the predominant form of selenium in all of the tissues; however their relative proportion varied across different tissues. In general, the organs primarily involved in selenium handling in fish (e.g., liver, kidney) accumulated a higher percentage of selenocystine. We also found that dietary selenomethionine exposure resulted into a marked increase in selenium burden of all major tissues in fish including the brain. Collectively, our findings provide new insights into the tissue-specific distribution and speciation of selenium in fish exposed to selenomethionine via diet.
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Affiliation(s)
- Sougat Misra
- Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5E2
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24
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Lenz M, van Hullebusch ED, Farges F, Nikitenko S, Corvini PFX, Lens PNL. Combined speciation analysis by X-ray absorption near-edge structure spectroscopy, ion chromatography, and solid-phase microextraction gas chromatography-mass spectrometry to evaluate biotreatment of concentrated selenium wastewaters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:1067-1073. [PMID: 21182285 DOI: 10.1021/es1022619] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study we evaluate the potential of anaerobic granular sludge as an inoculum for the bioremediation of selenium-contaminated waters using species-specific analytical methods. Solid species formed by microbial reduction were investigated using X-ray absorption near-edge structure (XANES) spectroscopy at the selenium K-edge. Furthermore, dissolved selenium species were specifically determined by ion chromatography (IC) and solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). Least-squares linear combination of the XANES spectra for samples incubated with the highest selenate/selenite concentrations (10(-3) M) show the predominance of elemental selenium and a Se(-I) selenide, such as ferroselite, the thermodynamically most stable iron selenide. In contrast, elemental selenium and Se(-II) selenides are the main species detected at the lower selenate/selenite concentrations. In each repeated fed batch incubation, most aqueous selenite anions were converted into solid selenium species, regardless of the type of electron donor used (acetate or H(2)/CO(2)) and the selenium concentration applied. On the other hand, at higher concentrations of selenate (10(-4) and 10(-3) M), significant amounts of the oxyanion remained unconverted after consecutive incubations. SPME-GC-MS demonstrated selenium alkylation with both electron donors investigated, as dimethyl selenide (DMSe) and dimethyl diselenide (DMDSe). Selenite was even more alkylated in the presence of H(2)/CO(2) (maximum 2156 μg of Se/L of DMSe + DMDSe) as compared to acetate (maximum 50 μg of Se/L). In contrast, selenate was less alkylated using both electron donors (maximum 166 and 3 μg of Se/L, respectively). The high alkylation potential for selenite limits its bioremediation in selenium laden waters involving H(2)/CO(2) as the electron donor despite the fact that nontoxic elemental selenium and thermodynamically stable metal selenide species are formed.
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Affiliation(s)
- Markus Lenz
- Sub-Department of Environmental Technology, Wageningen University, 6700 EV Wageningen, The Netherlands.
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25
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Oram LL, Strawn DG, Möller G. Chemical speciation and bioavailability of selenium in the rhizosphere of Symphyotrichum eatonii from reclaimed mine soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:870-875. [PMID: 21166454 DOI: 10.1021/es1029766] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Knowledge of rhizosphere influences on Se speciation and bioavailability is required to predict Se bioavailability to plants. In the present study, plant-availability of Se to aster (Symphyotrichum eatonii (A. Gray) G.L. Nesom) was compared in rhizosphere soils and nonrhizosphere (bulk) soils collected from a reclaimed mine site in southeastern Idaho, U.S. X-ray spectroscopy was used to characterize the oxidation state and elemental distribution of Se in aster roots, rhizosphere soils, and bulk soils. Percent extractable Se in aster rhizosphere soil was greater than extractable Se in corresponding bulk soils in all samples (n = 4, p = 0.042, 0.051, and 0.052 for three extractions). Selenium oxidation state mapping of 28 regions within the samples and X-ray absorption near edge structure (XANES) spectra from 26 points within the samples indicated that the rhizosphere and bulk soil Se species was predominantly reduced Se(-II,0), while in the aster roots, high concentrations of Se(VI) were present. Results show that within the rhizosphere, enhanced Se bioavailability is occurring via oxidation of reduced soil Se to more soluble Se(VI) species.
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Affiliation(s)
- Libbie L Oram
- Environmental Sciences Program, University of Idaho, Moscow, Idaho 83844-2339, United States
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Mitsunobu S, Takahashi Y, Terada Y. micro-XANES evidence for the reduction of Sb(V) to Sb(III) in soil from Sb mine tailing. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:1281-1287. [PMID: 20085342 DOI: 10.1021/es902942z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aim of this study was to determine the mechanism of Sb immobilization occurring under reductive soil conditions. In this work, we investigated the distribution and speciation of Sb in reductive soil formed in Sb mine tailing by micro-X-ray absorption near edge structure spectroscopy (micro-XANES) and electron probe microanalyzer (EPMA). EPMA and Fe K-edge micro-XANES analyses of the soil grains indicated that Sb in soil was strongly associated with Fe(III) hydroxides secondarily formed during sedimentation. The Sb concentrations in Sb hot-spot were found to be as high as 10-30 wt % (as Sb(2)O(5)). We also found quartz particles coated by secondary rims bearing Fe(III) hydroxides and Sb. The Sb K-edge micro-XANES analyses of the rims showed that a significant amount of Sb(III) was present only at the surfaces of the rims (thickness <10 microm), indicating that Sb reduction occurred in the reducing soil. The facts suggest that the reduction to Sb(III) in the system can be an important factor for Sb immobilization under reducing conditions, since the Sb(III) sorbs more strongly on Fe(III) hydroxides than Sb(V) and its solubility is also much lower than that of Sb(V) species.
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Affiliation(s)
- Satoshi Mitsunobu
- Institute for Environmental Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan.
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Misra S, Peak D, Niyogi S. Application of XANES spectroscopy in understanding the metabolism of selenium in isolated rainbow trout hepatocytes: insights into selenium toxicity. Metallomics 2010; 2:710-7. [DOI: 10.1039/c0mt00008f] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Missana T, Alonso U, García-Gutiérrez M. Experimental study and modelling of selenite sorption onto illite and smectite clays. J Colloid Interface Sci 2009; 334:132-8. [PMID: 19403144 DOI: 10.1016/j.jcis.2009.02.059] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Revised: 02/18/2009] [Accepted: 02/22/2009] [Indexed: 12/01/2022]
Abstract
This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated (from 1x10(-10) to 1x10(-3) M); and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions, as follows: (a) 30% illite-70% smectite and (b) 43% illite-57% smectite. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data, separately obtained in the single mineral systems, were modeled using both a one- and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. Although the use of a two-site model slightly improved the fit of data at a pH below 4, the simpler one-site model reproduced satisfactorily all the sorption data from pH 3 to 8. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/smectite mixtures; the model's predictions were consistent with the experimental adsorption data.
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Affiliation(s)
- T Missana
- CIEMAT, Departamento de Medioambiente Avenida Complutense 22, 28040 Madrid, Spain.
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Lenz M, van Hullebusch ED, Farges F, Nikitenko S, Borca CN, Grolimund D, Lens PNL. Selenium speciation assessed by X-ray absorption spectroscopy of sequentially extracted anaerobic biofilms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:7587-7593. [PMID: 18983079 DOI: 10.1021/es800811q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Wet chemical methods such as sequential extraction procedures are commonly used to assess selenium fractionation in anoxic environments, allowing an estimation of the mobility and bioavailability of selenium. However, the interpretation can be biased by unselective extraction of targeted species and artifacts introduced during the extraction. Here, the selectivity of the single extraction steps to gain reliable selenium speciation information are scrutinized for the first time by direct, nondestructive X-ray absorption near edge structure (XANES) spectroscopy at the selenium K-edge. The sequential extraction procedures seriously overestimated the elemental selenium fraction, as major parts (58%) of the total selenium were present as metal selenides and organic selenium compounds, although extracted in the elemental fraction. Spectral fitting of the XANES spectra by the least-squares linear combinations utilizing a large set of model compounds, including previously neglected Se(-I) selenides, showed a novel degree of complexity in the speciation of selenium treating anaerobic biofilms, with up to 4 modeled selenium species contributing to the speciation, i.e., different elemental, organic, and metal-bound selenium species. Furthermore, a short exposure (10 min) to ambient air during the sequential extraction procedure induced the oxidation of organic selenium compounds, revealing the fragility of selenium speciation in anaerobic biofilms.
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Affiliation(s)
- Markus Lenz
- Sub-Department of Environmental Technology, Wageningen University, Wageningen, The Netherlands
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Oram LL, Strawn DG, Marcus MA, Fakra SC, Möller G. Macro- and microscale investigation of selenium speciation in Blackfoot river, Idaho sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:6830-6836. [PMID: 18853796 DOI: 10.1021/es7032229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The transport and bioavailability of selenium in the environment is controlled by its chemical speciation. However, knowledge of the biogeochemistry and speciation of Se in streambed sediment is limited. We investigated the speciation of Se in sediment cores from the Blackfoot River (BFR), Idaho using sequential extractions and synchrotron-based micro-X-ray fluorescence (micro-SXRF). We collected micro-SXRF oxidation state maps of Se in sediments, which had not been done on natural sediment samples. Selective extractions showed that most Se in the sediments is present as either (1) nonextractable Se or (2) base extractable Se. Results from micro-SXRF showed three defined species of Se were present in all four samples: Se(-II,O), Se(IV), and Se(VI). Se(-II,O) was the predominant species in samples from one location, and Se(IV) was the predominant species in samples from a second location. Results from both techniques were consistent, and suggested that the predominant species were Se(-II) species associated with recalcitrant organic matter, and Se(IV) species tightly bound to organic materials. This information can be used to predict the biogeochemical cycling and bioavailability of Se in streambed sediment environments.
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Affiliation(s)
- Libbie L Oram
- Environmental Science Department, P.O. Box 442339, University of Idaho, Moscow, Idaho 83844-2339, USA.
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Pearce CI, Coker VS, Charnock JM, Pattrick RAD, Mosselmans JFW, Law N, Beveridge TJ, Lloyd JR. Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study. NANOTECHNOLOGY 2008; 19:155603. [PMID: 21825617 DOI: 10.1088/0957-4484/19/15/155603] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis.
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Affiliation(s)
- Carolyn I Pearce
- School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL, UK
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Terzano R, Spagnuolo M, Vekemans B, De Nolf W, Janssens K, Falkenberg G, Fiore S, Ruggiero P. Assessing the origin and fate of Cr, Ni, Cu, Zn, Pb, and V in industrial polluted soil by combined microspectroscopic techniques and bulk extraction methods. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:6762-9. [PMID: 17969692 DOI: 10.1021/es070260h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The major geochemical forms of Cr, Ni, Cu, Zn, Pb, and V in a soil from an industrial polluted site in the south of Italy were determined by means of synchrotron X-ray microanalytical techniques such as coupled micro-X-ray fluorescence/micro-X-ray diffraction and micro-X-ray absorption near edge structure spectroscopy in combination with bulk extraction methods (sequential extraction procedures, EDTA extractions, and toxicity leaching characteristic procedure tests). Cr, Ni, Zn, and Cu were found in spinel-type geochemical forms (chromite, trevorite, franklinite, zincochromite, and cuprospinel) and often in association with magnetite and hematite. Vwas mainly present as V(V) associated with iron-oxides or in the form of volborthite [Cu3(OH)2V2O7.2H2O]. Pb was speciated as minium (Pb3O4), lanarkite [Pb2O(SO4)], and, in association with Cr(VI), as crocoite (PbCrO4). In general, despite a high total concentration, metals appear to be speciated for the most part as rather insoluble geochemical forms. However, particular attention should be paid to Zn, Cu, V, and Pb that show non-negligible mobilizable fractions. On the basis of the geochemical forms identified, among others, two major former industrial activities were tentatively ascribed as being responsible for the observed major pollution: polyvinyl chloride and cement-asbestos productions.
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Affiliation(s)
- Roberto Terzano
- Dipartimento di Biologia e Chimica Agro-forestale ed Ambientale, Via Amendola 165/A, 1-70126, University of Bari, Bari, Italy.
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