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Dousova B, Buzek F, Cejkova B, Jackova I, Lnenickova Z. Thermal stability of arsenic complexes in soils. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125715. [PMID: 33838513 DOI: 10.1016/j.jhazmat.2021.125715] [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: 06/25/2020] [Revised: 01/06/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
The release of soil arsenic (As) in an unsaturated zone under oxidative conditions and at two temperatures simulating the seasonal effect (15 °C and 23 °C) was studied in four cultivated soils from the Elbe River catchment (Czech Republic, Central Europe). The soils with a low geogenic As background contained from 10 to 50 µg.g-1 of As, mostly originating from atmospheric deposition in the past. The temperature effect on the stability of As in soils was studied in connection with the stability of hydrated iron (Fe) oxides and dissolved organic carbon (DOC), as essential binding partners of As in soils. The temperature impact on As release was related to the actual As binding in soil determined by the sequential leaching. With predominant As binding to amorphous and poorly crystalline Fe phases the higher temperature (23 °C) increased As release up to twice compare to 15 °C. In the soils with a low total Fe and the preferential As binding to well-crystallised Fe phases the temperature effect on As release was negligible. Unlike Fe, the release of DOC is strongly temperature dependent, therefore As mobilisation was controlled by the DOC concentration. A higher experimental temperature (23 °C) supported the formation of DOC and the consequent release of As and Fe into the soil solution.
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Affiliation(s)
- Barbora Dousova
- University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic.
| | - Frantisek Buzek
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Bohuslava Cejkova
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Iva Jackova
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Zdena Lnenickova
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
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2
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Meharg AA, Meharg C. The Pedosphere as a Sink, Source, and Record of Anthropogenic and Natural Arsenic Atmospheric Deposition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7757-7769. [PMID: 34048658 DOI: 10.1021/acs.est.1c00460] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The Anthropocene has led to global-scale contamination of the biosphere through diffuse atmospheric dispersal of arsenic. This review considers the sources arsenic to soils and its subsequent fate, identifying key knowledge gaps. There is a particular focus on soil classification and stratigraphy, as this is central to the topic under consideration. For Europe and North America, peat core chrono-sequences record massive enhancement of arsenic depositional flux from the onset of the Industrial Revolution to the late 20th century, while modern mitigation efforts have led to a sharp decline in emissions. Recent arsenic wet and dry depositional flux measurements and modern ice core records suggest that it is South America and East Asia that are now primary global-scale polluters. Natural sources of arsenic to the atmosphere are primarily from volcanic emissions, aeolian soil dust entrainment, and microbial biomethylation. However, quantifying these natural inputs to the atmosphere, and subsequent redeposition to soils, is only starting to become better defined. The pedosphere acts as both a sink and source of deposited arsenic. Soil is highly heterogeneous in the natural arsenic already present, in the chemical and biological regulation of its mobility within soil horizons, and in interaction with climatic and geomorphological settings. Mineral soils tend to be an arsenic sink, while organic soils act as both a sink and a source. It is identified here that peatlands hold a considerable amount of Anthropocene released arsenic, and that this store can be potentially remobilized under climate change scenarios. Also, increased ambient temperature seems to cause enhanced arsine release from soils, and potentially also from the oceans, leading to enhanced rates of arsenic biogeochemical cycling through the atmosphere. With respect to agriculture, rice cultivation was identified as a particular concern in Southeast Asia due to the current high arsenic deposition rates to soil, the efficiency of arsenic assimilation by rice grain, and grain yield reduction through toxicity.
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Affiliation(s)
- Andrew A Meharg
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland
| | - Caroline Meharg
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland
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3
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Saldaña-Robles N, Damián-Ascencio C, Gutiérrez-Chávez A, Zanor G, Guerra-Sánchez R, Herrera-Díaz I, Saldaña-Robles A. Spatio-temporal groundwater arsenic distribution in Central Mexico: implications in accumulation of arsenic in barley (Hordeum vulgare L.) agrosystem. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:11333-11347. [PMID: 33123880 DOI: 10.1007/s11356-020-11317-7] [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: 05/05/2020] [Accepted: 10/18/2020] [Indexed: 06/11/2023]
Abstract
In the present work, a spatio-temporal study of arsenic (As) concentration in groundwater and its impact in barley uptake is presented. The impact of As on barley is studied through the determination of its bioaccumulation in the soil-plant system, As uptake, as well as a correlation between As concentration in water and its temperature in the groundwater. For the groundwater, spatial and temporal variability of As concentration in central Mexico was determined through a geostatistical analysis using ordinary kriging. The results show that the variability of As in the ground water is correlated with its temperature (R2 > 0.83). The As accumulation in the structures of plant follows the order root > leaf > ear in concentration. The bioaccumulation factor BAFT suggests that As is mobilized to the aerial parts of the barely for both As concentrations used in the irrigation water. However, for As concentration lower than 25 μg L-1, the BAFT is lower than 0.57, suggesting that the amount of As in root is the same as that contained in the aerial parts; whereas, for higher As concentrations (from 170 to 250 μg L-1), the BAFT is around 0.92, indicating that the As is mainly contained in root. The spatial distribution of As concentration trend in groundwaters along the time is the same, which means high As concentration areas remain in the same groundwaters and these areas are presenting the highest water temperature. These results shall contribute to understand the bioaccumulation of As in barley and the As spatial variability in central Mexico.
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Affiliation(s)
- Noé Saldaña-Robles
- Department of Agricultural Engineering, Universidad de Guanajuato, 36500, Irapuato, GTO, México
| | - Cesar Damián-Ascencio
- Department of Mechanical Engineering, Universidad de Guanajuato, 36886, Salamanca, GTO, Mexico
| | - Abner Gutiérrez-Chávez
- Department of Veterinary and Zootechny, Universidad de Guanajuato, 36500, Irapuato, GTO, Mexico
| | - Gabriela Zanor
- Department of Environmental Sciences, Universidad de Guanajuato, 36500, Irapuato, GTO, Mexico
| | | | - Israel Herrera-Díaz
- Department of Agricultural Engineering, Universidad de Guanajuato, 36500, Irapuato, GTO, México
| | - Adriana Saldaña-Robles
- Department of Agricultural Engineering, Universidad de Guanajuato, 36500, Irapuato, GTO, México.
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4
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Eberle A, Besold J, León Ninin JM, Kerl CF, Kujala K, Planer-Friedrich B. Potential of high pH and reduced sulfur for arsenic mobilization - Insights from a Finnish peatland treating mining waste water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143689. [PMID: 33279195 DOI: 10.1016/j.scitotenv.2020.143689] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/01/2020] [Accepted: 11/07/2020] [Indexed: 06/12/2023]
Abstract
Peatlands, used for purification of mining waste waters, have shown efficient solid-phase sequestration of contaminants such as arsenic (As). However, contaminant re-mobilization may occur related to management changes or chemical alteration of original peatland conditions. For a treatment peatland in Finnish Lapland, we here confirm efficient As retention in near-surface peat layers close to the mining waste water inflow, likely due to binding to FeIII-phases. Seven years into operation of the treatment peatland, there appears to be further retention potential, as large areas downstream still had solid-phase As concentrations at background levels. However, via depth-resolved pore water analysis we observed a hotspot 170 m from the inflow at 10-50 cm depth, where As pore water concentrations exceeded input concentrations by a factor of 20, indicating substantial As re-mobilization. At the same spot, a peak of reduced sulfur (S) species was found. Arsenic species detected were arsenite and up to 26% methylated oxyarsenates, 15% methylated and 7.9% inorganic thioarsenates. We postulate that As mobilization is a result of short-term re-equilibration to a changed inflow chemistry after installation of a process water treatment plant and a long-term consequence of changing pore water pH from acidic to near-neutral, releasing reduced S and As. We infer that the co-occurrence of reduced S and As leads to formation of methylated and/or thiolated As species with known low sorption affinity, thereby further enhancing As mobility. Laboratory incubation studies with two peat cores confirmed a high S-induced As mobilization potential, especially when As-Fe-rich, oxic surface layers were incubated anoxically at near-neutral pH. Highest risk of As re-mobilization from this treatment peatland is expected in a scenario in which mining waste water inflow has stopped but the peatland remains flooded, and near-surface layers transition from oxic to anoxic conditions.
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Affiliation(s)
- Anne Eberle
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Johannes Besold
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - José M León Ninin
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Carolin F Kerl
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Katharina Kujala
- Water Resources and Environmental Engineering Research Unit, University of Oulu, FI-90014 Oulu, Finland
| | - Britta Planer-Friedrich
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany.
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Abstract
Soil arsenic (As) pollution is still a major concern due to its high toxicity and carcinogenicity, thus, the study of decontamination techniques, as the organic amendment applications, keeps upgrading. This research evaluates the potential remediation of peat in different As-polluted soils, by assessing the decrease of As solubility and its toxicity through bioassays. Obtained reduction in As solubility by peat addition was strongly related to the increase of humic substances, providing colloids that allow the complexation of As compounds. Calcareous soils have been the least effective at buffering As pollution, with higher As concentrations and worse biological response (lower soil respiration and inhibition of lettuce germination). Non-calcareous soils showed lower As concentrations due to the higher iron content, which promotes As fixation. Although in both cases, peat addition improves the biological response, it also showed negative effects, hypothetically due to peat containing toxic polyphenolic compounds, which in the presence of carbonates appears to be concealed. Both peat dose tested (2% and 5%) decreased drastically As mobility; however, for calcareous soils, as there is no phytotoxic effect, the 5% dose is the most recommended; while for non-calcareous soils the efficient peat dose for As decontamination could be lower.
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Eberle A, Besold J, Kerl CF, Lezama-Pacheco JS, Fendorf S, Planer-Friedrich B. Arsenic Fate in Peat Controlled by the pH-Dependent Role of Reduced Sulfur. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6682-6692. [PMID: 32347724 DOI: 10.1021/acs.est.0c00457] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Reduced sulfur (S) has a contrasting role in the fate of arsenic (As) in peatlands. Sulfur bridges provide efficient binding of As to organic carbon (C), but the formation of aqueous As-S species, so-called thioarsenates, leads to a low to no sorption tendency to organic C functional groups. Here, we studied how pH changes the role of reduced S in desorption and retention of presorbed As in model peat. Control desorption experiments without S addition revealed that As was mobilized, predominantly as arsenite, in all treatments with relative mobilization increasing with pH (4.5 < 7.0 < 8.5). Addition of sulfide or polysulfide caused substantial As retention at acidic conditions but significantly enhanced As desorption compared to controls at neutral to alkaline pH. Thioarsenates dominated As speciation at pH 7.0 and 8.5 (maximum, 79%) and remained in solution without (re)sorption to peat. Predominance of arsenite in control experiments and no evidence of surface-bound thioarsenates at pH 7.0 suggest mobilization to proceed via arsenite desorption, reaction with dissolved or surface-bound reduced S, and formation of thioarsenates. Our results suggest that natural or management-related increases in pH or increases in reduced S in near-neutral pH environments can turn organic matter from an As sink into a source.
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Affiliation(s)
- Anne Eberle
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Johannes Besold
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Carolin F Kerl
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Juan S Lezama-Pacheco
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Scott Fendorf
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Britta Planer-Friedrich
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany
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Cai X, Wang P, Li Z, Li Y, Yin N, Du H, Cui Y. Mobilization and transformation of arsenic from ternary complex OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria. JOURNAL OF HAZARDOUS MATERIALS 2020; 381:120975. [PMID: 31445471 DOI: 10.1016/j.jhazmat.2019.120975] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 07/17/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
Organic matter (OM) was proved to have a high affinity for arsenic (As) in the presence of ferric iron (Fe(III)), the formed ternary complex OM-Fe(III)-As(V) were frequently studied before; however, the mobilization and transformation of As from OM-Fe(III)-As(V) in the presence of As(V)-reducing bacteria remains unclear. Two different strains (Desulfitobacterium sp. DJ-3, Exiguobacterium sp. DJ-4) were incubated with OM-Fe(III)-As(V) to assess the biotransformation of As and Fe. Results showed that Desulfitobacterium sp. DJ-3 could substantially stimulate the reduction and release of OM-Fe complexed As(V) and resulted in notable As(III) release (30 mg/L). The linear combination fitting result of k3-weighted As K-edge EXAFS spectra showed that 56% of OM-Fe-As(V) was transformed to OM-Fe-As(III) after 144 h. Besides, strain DJ-3 could also reduce OM complexed Fe(III), which lead to the decomposition of ternary complex and the release of 11.8 mg/g Fe(II), this microbial Fe(III) reduction process has resulted in 11% more As liberation from OM-Fe(III)-As(V) than without bacteria. In contrast, Exiguobacterium sp. DJ-4 could only reduce free As(V) but cannot stimulate As release from the complex. Our study provides the first evidence for microbial As reduction and release from ternary complex OM-Fe(III)-As(V), which could be of great importance in As geochemical circulation.
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Affiliation(s)
- Xiaolin Cai
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Pengfei Wang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Zejiao Li
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Yan Li
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Naiyi Yin
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Huili Du
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Yanshan Cui
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
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8
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Biswas A, Besold J, Sjöstedt C, Gustafsson JP, Scheinost AC, Planer-Friedrich B. Complexation of Arsenite, Arsenate, and Monothioarsenate with Oxygen-Containing Functional Groups of Natural Organic Matter: An XAS Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10723-10731. [PMID: 31436974 DOI: 10.1021/acs.est.9b03020] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Arsenic (As) is reported to be effectively sorbed onto natural organic matter (NOM) via thiol coordination and polyvalent metal cation-bridged ternary complexation. However, the extent of sorption via complexation with oxygen-containing functional groups of NOM is poorly understood. By equilibrating arsenite, arsenate, and monothioarsenate with purified model-peat, followed by As K-edge X-ray absorption spectroscopic analysis, this study shows that complexation with oxygen-containing functional groups can be an additional or alternative mode of As sorption to NOM. The extent of complexation was highest for arsenite, followed by monothioarsenate and arsenate. Complexation was higher at pH 7.0 compared to 4.5 for arsenite and arsenate and vice versa for monothioarsenate because of partial transformation to arsenite at pH 4.5. Modeling of the As K-edge extended X-ray absorption fine structure data revealed that As···C interatomic distances were relatively longer in arsenate- (2.83 ± 0.01 Å) and monothioarsenate-treated peat (2.80 ± 0.02 Å) compared to arsenite treatments (2.73 ± 0.01 Å). This study suggests that arsenite was predominantly complexed with carboxylic groups, whereas arsenate and monothioarsenate were complexed with alcoholic groups of the peat. This study further implies that in systems, where NOM is the major sorbent, arsenate and monothioarsenate can have higher mobility than arsenite.
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Affiliation(s)
- Ashis Biswas
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER) , Bayreuth University , 95440 Bayreuth , Germany
- Department of Earth and Environmental Sciences , Indian Institute of Science Education and Research (IISER) Bhopal , Bhopal Bypass Road , 462066 Bhauri , Madhya Pradesh , India
| | - Johannes Besold
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER) , Bayreuth University , 95440 Bayreuth , Germany
| | - Carin Sjöstedt
- Department of Soil and Environment , Swedish University of Agricultural Sciences , Box 7014, 750 07 Uppsala , Sweden
| | - Jon Petter Gustafsson
- Department of Soil and Environment , Swedish University of Agricultural Sciences , Box 7014, 750 07 Uppsala , Sweden
| | - Andreas C Scheinost
- The Rossendorf Beamline (ROBL) at ESRF , 38043 Grenoble , France
- Institute of Resource Ecology , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) , Bautzner Landstraße 400 , 01328 Dresden , Germany
| | - Britta Planer-Friedrich
- Department of Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER) , Bayreuth University , 95440 Bayreuth , Germany
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9
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Asta MP, Wang Y, Frutschi M, Viacava K, Loreggian L, Le Pape P, Le Vo P, Fernández AM, Morin G, Bernier-Latmani R. Microbially Mediated Release of As from Mekong Delta Peat Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10208-10217. [PMID: 31390183 DOI: 10.1021/acs.est.9b02887] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Peat layers within alluvial sediments are considered effective arsenic (As) sinks under reducing conditions due to the binding of As(III) to thiol groups in natural organic matter (NOM) and the formation of As-bearing sulfide phases. However, their possible role as sources of As for anoxic groundwaters remains unexplored. Here, we perform laboratory experiments to provide evidence for the role of a sediment peat layer in releasing As. Our results show that the peat layer, deposited about 8,000 years ago in a paleomangrove environment in the nascent Mekong Delta, could be a source of As to porewater under reducing conditions. X-ray absorption spectroscopy (XAS) analysis of the peat confirmed that As was bound to NOM thiol groups and incorporated into pyrite. Nitrate was detected in peat layer porewater, and flow-through and batch experiments evidenced the release of As from NOM and pyrite in the presence of nitrate. Based on poisoning experiments, we propose that the microbially mediated oxidation of arsenic-rich pyrite and organic matter coupled to nitrate reduction releases arsenic from this peat. Although peat layers have been proposed as As sinks in earlier studies, we show here their potential to release depositional- and/or diagenetically-accumulated As.
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Affiliation(s)
- Maria P Asta
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
| | - Yuheng Wang
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
| | - Manon Frutschi
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
| | - Karen Viacava
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
| | - Luca Loreggian
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
| | - Pierre Le Pape
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC, CNRS-UPMC-IRD-MNHN UMR 7590) , Centre National de la Recherche Scientifique (CNRS) - Université Pierre et Marie Curie (UPMC Paris 6) , Campus Jussieu, 4 place Jussieu , 75005 Paris , France
| | - Phu Le Vo
- Faculty of Environment & Natural Resources , Ho Chi Minh City University of Technology - VNU HCM , 268 Ly Thuong Kiet st., Dist. 10 , Ho Chi Minh City 70000 , Vietnam
| | - Ana María Fernández
- Departamento de Medio Ambiente , Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) , Madrid 28040 , Spain
| | - Guillaume Morin
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC, CNRS-UPMC-IRD-MNHN UMR 7590) , Centre National de la Recherche Scientifique (CNRS) - Université Pierre et Marie Curie (UPMC Paris 6) , Campus Jussieu, 4 place Jussieu , 75005 Paris , France
| | - Rizlan Bernier-Latmani
- Environmental Microbiology Laboratory (EML) , École Polytechnique Fédérale de Lausanne (EPFL) , Station 6 , CH-1015 Lausanne , Switzerland
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10
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Liu J, Wang Z, Zhao H, Peros M, Yang Q, Liu S, Li H, Wang S, Bu Z. Mercury and arsenic in the surface peat soils of the Changbai Mountains, northeastern China: distribution, environmental controls, sources, and ecological risk assessment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:34595-34609. [PMID: 30315532 DOI: 10.1007/s11356-018-3380-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
The potential toxic risk of mercury (Hg) and arsenic (As) in the soils of mining regions and other artificially disturbed lands receives considerable research attention. However, limited investigation has been conducted into the surface soils of natural globally distributed ecosystems, for example peatlands. In this study, we examine the distribution, controlling factors, sources, and potential ecological risks of Hg and As in 96 samples from 42 peatlands in the Changbai Mountains of northeastern China. The results showed that average concentrations (dry weight) of Hg and As at the samples sites were 169.1 ± 0.1 µg kg-1 and 13.0 ± 7.7 mg kg-1, respectively. The distribution of Hg is largely determined by latitude and altitude, while As is controlled more by pH, total organic carbon (TOC), and ratio of TOC and nitrogen (C/N) at the regional scale. Variations in TOC, C/N ratio, and redox conditions contribute to determining the distribution of Hg, while TOC and redox conditions mainly affected the distribution of Arsenic at the local scale. Mercury mostly comes from regional atmospheric wet deposition, whereas elevated concentrations of As are related to local anthropogenic activities. Overall, Hg and As in the peatlands of the Changbai Mountains pose a moderate level of potential risk to ecological health.
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Affiliation(s)
- Jia Liu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Zucheng Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Hongyan Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China.
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China.
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, 130024, Jilin, China.
| | - Matthew Peros
- Department of Environment and Geography, Bishop's University, Sherbrooke, Québec, J1M 1Z7, Canada
| | - Qiannan Yang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Shasha Liu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Hongkai Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Shengzhong Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Zhaojun Bu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, Jilin, China
- Institute for Peat & Mire Research, Northeast Normal University, Changchun, 130024, Jilin, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, 130024, Jilin, China
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11
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Bohdálková L, Bohdálek P, Břízová E, Pacherová P, Kuběna AA. Atmospheric metal pollution records in the Kovářská Bog (Czech Republic) as an indicator of anthropogenic activities over the last three millennia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:857-874. [PMID: 29602122 DOI: 10.1016/j.scitotenv.2018.03.142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/13/2018] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
Three peat cores were extracted from the Kovářská Bog in the central Ore Mountains to study anthropogenic pollution generated by mining and metallurgy. The core profiles were 14C dated, and concentrations of selected elements were determined by ICP MS and HG-AAS. Principal component analysis indicated that Pb, Cu, As and Ag may be useful elements for the reconstruction of historical atmospheric pollution. Total and anthropogenic accumulation rates (ARs) of Pb, Cu and As estimated for the last ca. 3500years showed similar chronologies, and revealed twelve periods of elevated ARs of Pb, As and Cu related to possible mining and metallurgic activities. In total, four periods of elevated ARs of Pb, Cu and As were detected during the Middle and Late Bronze Ages, including a distinct Late Bronze Age pollution event between 1030BCE and 910BCE. The Iron Age included three episodes of increased ARs of Pb and As; the first and the most distinctive episode, recorded between 730 and 440BCE, was simultaneous with the Bylany culture during the Hallstatt Period. The Roman Age was characterized by one pollution event, two events were detected in the Middle Ages, and the last two during the modern period. Enhanced element ARs in the late 12th and 15th centuries clearly documented the onset of two periods of intense mining in the Ore Mountains. Metal ARs culminated in ca. 1600CE, and subsequently decreased after the beginning of the Thirty Years' War. The last boom of mining between 1700CE and 1830CE represented the last period of important metallurgical operations. Late Medieval and modern period metal ARs are in good agreement with written documents. Earlier pollution peaks suggest that local metal production could have a much longer tradition than commonly believed; however, archaeological or written evidence is scarce or lacking.
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Affiliation(s)
- Leona Bohdálková
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic; Global Change Research Institute, AS CR, Belidla 986/4a, 603 00 Brno, Czech Republic.
| | - Petr Bohdálek
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Eva Břízová
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Petra Pacherová
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Aleš Antonín Kuběna
- Department of Social and Clinical Pharmacy, Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
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Pratte S, Bao K, Shen J, Mackenzie L, Klamt AM, Wang G, Xing W. Recent atmospheric metal deposition in peatlands of northeast China: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:1284-1294. [PMID: 29898536 DOI: 10.1016/j.scitotenv.2018.01.183] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 01/18/2018] [Accepted: 01/18/2018] [Indexed: 06/08/2023]
Abstract
China is one of the fastest-growing economies of the late 20th and early 21st centuries, and heavy metal emissions have increased in parallel with rapid industrialization and urbanization. Over the last decade, several studies of geochemical records from peat have reconstructed changes in atmospheric metal pollution in China. We review the peat records that detail the history of atmospheric metal pollution over the last two centuries in NE China. The ecological risk (ER) of accumulated metals and their potential eco-toxicological effects, through threshold and probable effect concentrations (TEC and PEC), are also evaluated. Peat records of metals show an increase of pollution loads in the environment over the pre-industrial level during the past two centuries, with an unprecedented increase in China over the last 60 years. There is generally good agreement between geochemical peat records from NE China and others records elsewhere in China. However, some discrepancies are observed especially with Hg records from lake sediments. These discrepancies could be explained by several factors, including post-depositional processes or uncertainties arising from dating methods. The ecological risk of heavy metals is found to be relatively weak in the remote and high-altitude environment in NE China. Although, most metals are under the TEC, Pb concentrations usually surpass it and are getting close to the PEC which indicates increasing ecological risks. Some areas of improvement have been highlighted such as the need for more long-term studies on atmospheric metals and a greater number of Pb isotopes records to better capture the long history of human activity and the spatial variability in metal deposition of the region.
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Affiliation(s)
- Steve Pratte
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Kunshan Bao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Ji Shen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Lydia Mackenzie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Anna-Marie Klamt
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Guoping Wang
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Wei Xing
- School of Geographic Sciences, Xinyang Normal University, Xinyang 464000, China
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13
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Zaccone C, Lobianco D, Raber G, D'Orazio V, Shotyk W, Miano TM, Francesconi K. Methylated arsenic species throughout a 4-m deep core from a free-floating peat island. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:67-74. [PMID: 29175622 DOI: 10.1016/j.scitotenv.2017.11.152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/11/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Arsenic (As) occurs in soils mostly in inorganic forms, whereas the organic forms usually occur only in trace amounts. Peatlands are waterlogged, generally anoxic, organic soils representing the first step in coal formation; the contribution of organic vs. inorganic As species in this environment has received little research attention. Here, 57 peat samples collected throughout a 4-m deep, free-floating mire were analysed for total As and for its organic species, including dimethylarsinic acid (DMA), methylarsonic acid (MA), trimethylarsine oxide (TMAO) and arsenobetaine (AB), by HPLC-ICPMS. Aqueous trifluoroacetic acid was used as extractant, resulting in an average extraction efficiency of almost 80%. Total As concentration throughout the profile ranged between 0.2 and 9.8mg/kgpeat (mean: 1.4±1.2mg/kgpeat). Organic As species (DMA+MA+TMAO+AB) accounted, on average, for 28±10% of total As (range: 6-51%), and for 37±13% of the extracted As (range: 7-64%). The relative abundance of organoarsenicals generally followed the order DMA>TMAO~MA≫AB. A positive correlation (p<0.001) was found among all organic As compounds, whereas their concentrations were negatively correlated with total sulfur content. The submerged zone (bottom 300cm) showed average and maximum concentrations of organoarsenic compounds that were almost twice those found in the top 100cm. This study shows that significant proportions of methylated As species occur even in peat samples characterized by low total As concentration (mostly <2mg/kg). Finally, this work provides the first evidence of organoarsenic species in free-floating mires, i.e., a globally distributed but scarcely investigated ecosystem.
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Affiliation(s)
- Claudio Zaccone
- Department of the Sciences of Agriculture, Food and Environment, University of Foggia, via Napoli 25, 71122 Foggia, Italy.
| | - Daniela Lobianco
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", via Amendola 165/A, 70126 Bari, Italy
| | - Georg Raber
- Institute of Chemistry, NAWI Graz, University of Graz, Austria
| | - Valeria D'Orazio
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", via Amendola 165/A, 70126 Bari, Italy
| | - William Shotyk
- Department of Renewable Resources, University of Alberta, 348B South Academic Building, T6G 2H1 Edmonton, Canada
| | - Teodoro M Miano
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", via Amendola 165/A, 70126 Bari, Italy
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14
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Spatial Variations in the Surface Water Chemistry of Subtropical Peatlands (Central China) Linked to Anthropogenic Pressures. WATER 2017. [DOI: 10.3390/w9070505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Shotyk W, Appleby PG, Bicalho B, Davies LJ, Froese D, Grant-Weaver I, Magnan G, Mullan-Boudreau G, Noernberg T, Pelletier R, Shannon B, van Bellen S, Zaccone C. Peat Bogs Document Decades of Declining Atmospheric Contamination by Trace Metals in the Athabasca Bituminous Sands Region. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6237-6249. [PMID: 28485980 DOI: 10.1021/acs.est.6b04909] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Peat cores were collected from five bogs in the vicinity of open pit mines and upgraders of the Athabasca Bituminous Sands, the largest reservoir of bitumen in the world. Frozen cores were sectioned into 1 cm slices, and trace metals determined in the ultraclean SWAMP lab using ICP-QMS. The uppermost sections of the cores were age-dated with 210Pb using ultralow background gamma spectrometry, and selected plant macrofossils dated using 14C. At each site, trace metal concentrations as well as enrichment factors (calculated relative to the corresponding element/Th ratio of the Upper Continental Crust) reveal maximum values 10 to 40 cm below the surface which shows that the zenith of atmospheric contamination occurred in the past. The age-depth relationships show that atmospheric contamination by trace metals (Ag, Cd, Sb, Tl, but also V, Ni, and Mo which are enriched in bitumen) has been declining in northern Alberta for decades. In fact, the greatest contemporary enrichments of Ag, Cd, Sb, and Tl (in the top layers of the peat cores) are found at the control site (Utikuma) which is 264 km SW, suggesting that long-range atmospheric transport from other sources must be duly considered in any source assessment.
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Affiliation(s)
- William Shotyk
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Peter G Appleby
- Department of Mathematical Sciences, University of Liverpool , Liverpool L69 3BX, United Kingdom
| | - Beatriz Bicalho
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Lauren J Davies
- Department of Earth and Atmospheric Sciences, University of Alberta , Edmonton, Alberta T6G 2E3, Canada
| | - Duane Froese
- Department of Earth and Atmospheric Sciences, University of Alberta , Edmonton, Alberta T6G 2E3, Canada
| | - Iain Grant-Weaver
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Gabriel Magnan
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
- Département de Géographie, Université du Québec à Montréal Montréal, Québec H2V 2B8, Canada
| | - Gillian Mullan-Boudreau
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Tommy Noernberg
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Rick Pelletier
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
| | - Bob Shannon
- Quality Radioanalytical Support, LLC, 123 Cougar Trail, PO Box 774 Grand Marais, Minnesota 55604, United States
| | - Simon van Bellen
- Department of Renewable Resources, University of Alberta , 348B South Academic Building, Edmonton, Alberta T6G 2H1, Canada
- Département de Géographie, Université du Québec à Montréal Montréal, Québec H2V 2B8, Canada
| | - Claudio Zaccone
- Department of the Sciences of Agriculture, Food and Environment, University of Foggia, Via Napoli , 71122 Foggia, Italy
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Mikutta C, Rothwell JJ. Peat Bogs as Hotspots for Organoarsenical Formation and Persistence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:4314-4323. [PMID: 27034028 DOI: 10.1021/acs.est.5b06182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Peatlands have received significant atmospheric inputs of As and S since the onset of the Industrial Revolution, but the effect of S deposition on the fate of As is largely unknown. It may encompass the formation of As sulfides and organosulfur-bound As, or the indirect stimulation of As biotransformation processes, which are presently not considered as important As immobilization pathways in wetlands. To investigate the immobilization mechanisms of anthropogenically derived As in peatlands subjected to long-term atmospheric pollution, we explored the solid-phase speciation of As, Fe, and S in English peat bogs by X-ray absorption spectroscopy. Additionally, we analyzed the speciation of As in pore- and streamwaters. Linear combination fits of extended X-ray absorption fine structure (EXAFS) data imply that 62-100% (average: 82%) of solid-phase As (Astot: 9-92 mg/kg) was present as organic As(V) and As(III). In agreement with appreciable concentrations of organoarsenicals in surface waters (pH: 4.0-4.4, Eh: 165-190 mV, average Astot: 1.5-129 μg/L), our findings reveal extensive biotransformation of atmospheric As and the enrichment of organoarsenicals in the peat, suggesting that the importance of organometal(loid)s in wetlands subjected to prolonged air pollution is higher than previously assumed.
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Affiliation(s)
- Christian Mikutta
- Section for Environmental Chemistry and Physics, Department of Plant and Environmental Sciences, University of Copenhagen , DK-1871 Frederiksberg C, Denmark
- Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zurich , 8092 Zurich, Switzerland
| | - James J Rothwell
- Upland Environments Research Unit, Geography, School of Environment, Education and Development, The University of Manchester , Manchester M13 9PL, U.K
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17
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Dousova B, Buzek F, Lhotka M, Krejcova S, Boubinova R. Leaching effect on arsenic mobility in agricultural soils. JOURNAL OF HAZARDOUS MATERIALS 2016; 307:231-239. [PMID: 26785213 DOI: 10.1016/j.jhazmat.2015.12.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 12/03/2015] [Accepted: 12/17/2015] [Indexed: 06/05/2023]
Abstract
The stability of soil arsenic during long-term leaching was studied in four soils from an agricultural area. Two identical columns simulating soil profiles of three layers were leached with As-free natural rainwater (<3.10(-3)mgL(-1) As) to test As mobility and the same rainwater enriched with As(V) (2.5mgL(-1) As) for the study of As accumulation. The relative As flow (μgg(-1)day(-1)) showed a comparable run for all soils, with the peak corresponding to maximum As release in the first leaching stage, and then with a tendency to equilibrate. The amount of released As was controlled by the saturated hydraulic conductivity Ksat and free Fe oxides, and the kinetics of the leaching process correlated with the content of organic matter (OM). An overall stability and accumulation of soil arsenic were mostly affected by soil properties (Ksat, particle size, clay fraction), while the chemical composition (Fe, OM content) and surface properties (specific surface area SBET, theoretical adsorption capacity Qt) were of marginal significance. The distribution of As forms was performed by sequential extraction (SEP), which indicated negligible transformation (<12%) of As species in upper soil layers.
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Affiliation(s)
- Barbora Dousova
- University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic.
| | - Frantisek Buzek
- Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Miloslav Lhotka
- University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
| | - Stanislava Krejcova
- University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
| | - Radka Boubinova
- University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
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18
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de Oliveira LK, Melo CA, Goveia D, Lobo FA, Armienta Hernández MA, Fraceto LF, Rosa AH. Adsorption/desorption of arsenic by tropical peat: influence of organic matter, iron and aluminium. ENVIRONMENTAL TECHNOLOGY 2015; 36:149-59. [PMID: 25413109 DOI: 10.1080/09593330.2014.939999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The objective of this work was to investigate the interaction of arsenic species (As(III) and As(V)) with tropical peat. Peat samples collected in Brazil were characterized using elemental analysis and 13C NMR. Adsorption experiments were performed using different concentrations of As with peat in natura and enriched with Fe or Al, at three different pH levels. Peat samples, in natura or enriched with metals, were analysed before and after adsorption processes using Fourier transform infrared spectroscopy (FTIR) spectroscopy. The adsorption kinetics was evaluated, and the data were fitted using the Langmuir and Freundlich models. The results showed that interaction between As and peat was dependent on the levels of organic matter (OM) and the metals (Fe and Al). As(III) was not adsorbed by in natura peat or Al-enriched peat, although small amounts of As(III) were adsorbed by Fe-enriched peat. Adsorption of As(V) by the different peat samples ranged from 21.3 to 52.7 μg g(-1). The best fit to the results was obtained using the pseudo-second-order kinetic model, and the adsorption of As(V) could be described by the Freundlich isotherm model. The results showed that Fe-enriched peat was most effective in immobilizing As(V). FTIR analysis revealed the formation of ternary complexes involving As(V) and peat enriched with metals, suggesting that As(V) was associated with Al or Fe-OM complexes by metal bridging.
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Affiliation(s)
- Lílian Karla de Oliveira
- a Institute of Chemistry , São Paulo State University (UNESP) , Rua Prof. Francisco Degni 55, Araraquara SP 18087-180 , Brazil
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Langner P, Mikutta C, Kretzschmar R. Oxidation of organosulfur-coordinated arsenic and realgar in peat: implications for the fate of arsenic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:2281-2289. [PMID: 24410569 DOI: 10.1021/es4049785] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Organosulfur-coordinated As(III) and realgar (α-As4S4) have been identified as the dominant As species in the naturally As-enriched minerotrophic peatland Gola di Lago, Switzerland. In this study, we explored their oxidation kinetics in peat exposed to atmospheric O2 for up to 180 days under sterile and nonsterile conditions (25 °C, ∼ 100% relative humidity). Anoxic peat samples were collected from a near-surface (0-38 cm) and a deep peat layer (200-250 cm) and studied by bulk As, Fe, and S K-edge X-ray absorption spectroscopy as well as selective extractions as a function of time. Over 180 days, only up to 33% of organosulfur-coordinated As(III) and 44% of realgar were oxidized, corresponding to half-life times, t1/2, of 312 and 215 days, respectively. The oxidation of both As species was mainly controlled by abiotic processes. Realgar was oxidized orders of magnitude slower than predicted from published mixed-flow reactor experiments, indicating that mass-transfer processes were rate-limiting. Most of the As released (>97%) was sequestered by Fe(III)-(hydr)oxides. However, water-extractable As reached concentrations of 0.7-19 μmol As L(-1), exceeding the WHO drinking water limit by up to 145 times. Only a fraction (20-36%) of reduced S(-II to I) was sensitive to oxidation and was oxidized faster (t1/2 = 50-173 days) than organosulfur-coordinated As(III) and realgar, suggesting a rapid loss of reactive As-sequestering S species following a drop in the water table. Our results imply that wetlands like Gola di Lago can serve as long-term sources for As under prolonged oxidizing conditions. The maintenance of reducing conditions is thus regarded as the primary strategy in the management of this and other As-rich peatlands.
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Affiliation(s)
- Peggy Langner
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, CHN, ETH Zurich , CH-8092 Zurich, Switzerland
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20
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Hoffmann M, Mikutta C, Kretzschmar R. Arsenite binding to natural organic matter: spectroscopic evidence for ligand exchange and ternary complex formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:12165-73. [PMID: 24088046 DOI: 10.1021/es4023317] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The speciation of As in wetlands is often controlled by natural organic matter (NOM), which can form strong complexes with Fe(III). Here, we elucidated the molecular-scale interaction of arsenite (As(III)) with Fe(III)-NOM complexes under reducing conditions. We reacted peat (40-250 μm size fraction, 1.0 g Fe/kg) with 0-15 g Fe/kg at pH <2, removed nonreacted Fe, and subsequently equilibrated the Fe(III) complexes formed with 900 mg As/kg peat at pH 7.0, 8.4, and 8.8. The solid-phase speciation of Fe and As was studied by electron paramagnetic resonance (Fe) and X-ray absorption spectroscopy (As, Fe). Our results show that the majority of Fe in the peat was present as mononuclear Fe(III) species (RFe-C = 2.82-2.88 Å), probably accompanied by small Fe(III) clusters of low nuclearity (RFe-Fe = 3.25-3.46 Å) at high pH and elevated Fe contents. The amount of As(III) retained by the original peat was 161 mg As/kg, which increased by up to 250% at pH 8.8 and an Fe loading of 7.3 g/kg. With increasing Fe content of peat, As(III) increasingly formed bidentate mononuclear (RAs-Fe = 2.88-2.94 Å) and monodentate binuclear (RAs-Fe = 3.35-3.41 Å) complexes with Fe, thus yielding direct evidence of ternary complex formation. The ternary complex formation went along with a ligand exchange reaction between As(III) and hydroxylic/phenolic groups of the peat (RAs-C = 2.70-2.77 Å). Our findings thus provide spectroscopic evidence for two yet unconfirmed As(III)-NOM interaction mechanisms, which may play a vital role in the cycling of As in sub- and anoxic NOM-rich environments such as peatlands, peaty sediments, swamps, or rice paddies.
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Affiliation(s)
- Martin Hoffmann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich , CHN, CH-8092 Zurich, Switzerland
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21
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Allan M, Le Roux G, De Vleeschouwer F, Bindler R, Blaauw M, Piotrowska N, Sikorski J, Fagel N. High-resolution reconstruction of atmospheric deposition of trace metals and metalloids since AD 1400 recorded by ombrotrophic peat cores in Hautes-Fagnes, Belgium. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 178:381-394. [PMID: 23619507 DOI: 10.1016/j.envpol.2013.03.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 03/11/2013] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
The objective of our study was to determine the trace metal accumulation rates in the Misten bog, Hautes-Fagnes, Belgium, and assess these in relation to established histories of atmospheric emissions from anthropogenic sources. To address these aims we analyzed trace metals and metalloids (Pb, Cu, Ni, As, Sb, Cr, Co, V, Cd and Zn), as well as Pb isotopes, using XRF, Q-ICP-MS and MC-ICP-MS, respectively in two 40-cm peat sections, spanning the last 600 yr. The temporal increase of metal fluxes from the inception of the Industrial Revolution to the present varies by a factor of 5-50, with peak values found between AD 1930 and 1990. A cluster analysis combined with Pb isotopic composition allows the identification of the main sources of Pb and by inference of the other metals, which indicates that coal consumption and metallurgical activities were the predominant sources of pollution during the last 600 years.
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Affiliation(s)
- Mohammed Allan
- AGEs, Département de Géologie, Université de Liège, Allée du 6 Août, B18 Sart Tilman B-4000, Liège, Belgium.
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Hoffmann M, Mikutta C, Kretzschmar R. Bisulfide reaction with natural organic matter enhances arsenite sorption: insights from X-ray absorption spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11788-11797. [PMID: 23075303 DOI: 10.1021/es302590x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Terrestrial ecosystems rich in natural organic matter (NOM) can act as a sink for As. Recently, the complexation of trivalent As by sulfhydryl groups of NOM was proposed as the main mechanism for As-NOM interactions in anoxic S- and NOM-rich environments. Here we tested the molecular-scale interaction of bisulfide (S(-II)) with NOM and its consequences for arsenite (As(III)) binding. We reacted 0.2 mol C/L peat and humic acid (HA) with up to 5.8 mM S(-II) at pH 7 and 5, respectively, and subsequently equilibrated the reaction products with 55 μM As(III) under anoxic conditions. The speciation of S and the local coordination environment of As in the solid phase were studied by X-ray absorption spectroscopy. Our results document a rapid reaction of S(-II) with peat and HA and the concomitant formation of reduced organic S species. These species were highly reactive toward As(III). Shell fits of As K-edge extended X-ray absorption fine structure spectra revealed that the coordination environment of trivalent As was progressively occupied by S atoms. Fitted As-S distances of 2.24-2.34 Å were consistent with sulfhydryl-bound As(III). Besides As(III) complexation by organic monosulfides, our data suggests the formation of nanocrystalline As sulfide phases in HA samples and an As sorption process for both organic sorbents in which As(III) retained its first-shell oxygens. In conclusion, this study documents that S(-II) reaction with NOM can greatly enhance the ability of NOM to bind As in anoxic environments.
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Affiliation(s)
- Martin Hoffmann
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, CH-8092 Zurich, Switzerland
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Mikutta C, Kretzschmar R. Spectroscopic evidence for ternary complex formation between arsenate and ferric iron complexes of humic substances. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:9550-7. [PMID: 21985502 DOI: 10.1021/es202300w] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Formation of ternary complexes between arsenic (As) oxyanions and ferric iron (Fe) complexes of humic substances (HS) is often hypothesized to represent a major mechanism for As-HS interactions under oxic conditions. However, direct evidence for this potentially important binding mechanism is still lacking. To investigate the molecular-scale interaction between arsenate, As(V), and HS in the presence of Fe(III), we reacted fulvic and humic acids with Fe(III) (1 wt %) and equilibrated the Fe(III)-HS complexes formed with As(V) at pH 7 (molar Fe/As ~10). The local (<5 Å) coordination environments of As and Fe were subsequently studied by means of X-ray absorption spectroscopy. Our results show that 4.5-12.5 μmol As(V)/g HS (25-70% of total As) was associated with Fe(III). At least 70% of this As pool was bound to Fe(III)-HS complexes via inner-sphere complexation. Results obtained from shell fits of As K-edge extended X-ray absorption fine structure (EXAFS) spectra were consistent with a monodentate binuclear ((2)C) and monodentate mononuclear ((1)V) complex stabilized by H-bonds (R(As-Fe) = 3.30 Å). The analysis of Fe K-edge EXAFS spectra revealed that Fe in Fe(III)-HS complexes was predominantly present as oligomeric Fe(III) clusters at neutral pH. Shell-fit results complied with a structural motif in which three corner-sharing Fe(O,OH)(6) octahedra linked by a single μ(3)-O bridge form a planar Fe trimer. In these complexes, the average Fe-C and Fe-Fe bond distances were 2.95 Å and 3.47 Å, respectively. Our study provides the first spectroscopic evidence for ternary complex formation between As(V) and Fe(III)-HS complexes, suggesting that this binding mechanism is of fundamental importance for the cycling of oxyanions such as As(V) in organic-rich, oxic soils and sediments.
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Affiliation(s)
- Christian Mikutta
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Sciences, ETH Zurich, 8092 Zurich, Switzerland.
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Rothwell JJ, Taylor KG, Evans MG, Allott TEH. Contrasting controls on arsenic and lead budgets for a degraded peatland catchment in Northern England. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:3129-3133. [PMID: 21683489 DOI: 10.1016/j.envpol.2011.05.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 05/21/2011] [Accepted: 05/26/2011] [Indexed: 05/30/2023]
Abstract
Atmospheric deposition of trace metals and metalloids from anthropogenic sources has led to the contamination of many European peatlands. To assess the fate and behaviour of previously deposited arsenic and lead, we constructed catchment-scale mass budgets for a degraded peatland in Northern England. Our results show a large net export of both lead and arsenic via runoff (282 ± 21.3 gPb ha(-1) y(-1) and 60.4 ± 10.5 gAs ha(-1) y(-1)), but contrasting controls on this release. Suspended particulates account for the majority of lead export, whereas the aqueous phase dominates arsenic export. Lead release is driven by geomorphological processes and is a primary effect of erosion. Arsenic release is driven by the formation of a redox-dynamic zone in the peat associated with water table drawdown, a secondary effect of gully erosion. Degradation of peatland environments by natural and anthropogenic processes has the potential to release the accumulated pool of legacy contaminants to surface waters.
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Affiliation(s)
- James J Rothwell
- Upland Environments Research Unit, School of Environment and Development, The University of Manchester, Manchester M13 9PL, UK.
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Rowland AP, Neal C, Reynolds B, Jarvie HP, Sleep D, Lawlor AJ, Neal M. The biogeochemistry of arsenic in a remote UK upland site: trends in rainfall and runoff, and comparisons with urban rivers. ACTA ACUST UNITED AC 2011; 13:1255-63. [PMID: 21442109 DOI: 10.1039/c0em00772b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ten years of monitoring of rainfall and streams in the remote acidic and acid sensitive moorland and afforested moorland of upland mid-Wales reveals concentrations of arsenic (As) typically <1 µg L(-1). On average, the lowest concentrations occur within rainfall and they have declined over time probably in response to reductions in global emissions. There is a corresponding reduction within the streams except for forested systems where concentrations up to doubled following clear-fell. Within the streams there are both annual cycling and diurnal cycling of As. The annual cycling gives maxima during the summer months and this probably reflects the importance of groundwater inputs and mineralisation/desorption from the surface soil layers. Correspondingly, the diurnal cycling occurs during the summer months at low flow periods with As concentrations highest in the afternoon/evening. For the urban/industrial basins of northern England with historically a much higher As deposition, land contamination and effluent discharges, comparative data indicate As concentrations around three fold higher: strong seasonal patterns are observed for the same reasons as with the uplands. Across the sites, the As concentrations are over an order of magnitude lower than that of environmental concern. Nonetheless, the results clearly show the effects of declining emissions on rainfall deposition and some indication of areas of historic contamination. Arsenic is mainly present in the <0.45 fraction, but cross-flow filtration indicates that approx. 43% is in the colloidal phase at the clean water sites, and 16% in the colloidal phase at the contaminated sites. Part of this colloidal component may well be associated with organic carbon.
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Affiliation(s)
- A P Rowland
- Centre for Ecology and Hydrology, Library Avenue, Lancaster, LA1 4AP, UK.
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26
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Novak M, Erbanova L, Fottova D, Cudlin P, Kubena A. Behaviour of arsenic in forested catchments following a high-pollution period. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:204-211. [PMID: 20932620 DOI: 10.1016/j.envpol.2010.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 08/30/2010] [Accepted: 09/06/2010] [Indexed: 05/30/2023]
Abstract
Due to high availability of adsorption sites, forested catchments could be net sinks for pollutant arsenic both during the period of increasing and decreasing pollution. We tested this hypothesis along a north-south pollution gradient in spruce die-back affected areas of Central Europe. For two water years (2007-2008), we monitored As fluxes via spruce-canopy throughfall, open-area precipitation, and runoff in four headwater catchments (Czech Republic). Since 1980, atmospheric As inputs decreased 26 times in the north, and 13 times in the south. Arsenic export by runoff was similar to atmospheric inputs at three sites, resulting in a near-zero As mass balance. One site exhibited a net export of As (2.2 g ha(-1) yr(-1)). In contrast, the preceding period (1995-2006) showed much higher As fluxes, and higher As export. Czech catchments do not serve as net sinks of atmospheric As. A considerable proportion of old industrial arsenic is flushed out of the soil.
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Affiliation(s)
- Martin Novak
- Department of Geochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic.
| | - Lucie Erbanova
- Department of Geochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Daniela Fottova
- Department of Geochemistry, Czech Geological Survey, Geologicka 6, 152 00 Prague 5, Czech Republic
| | - Pavel Cudlin
- Institute of Systems Biology and Ecology, Academy of Sciences of the Czech Republic, Na Sadkach 7, 370 05 Ceske Budejovice, Czech Republic
| | - Ales Kubena
- Faculty of Science, Charles University, Vinicna 7, 128 44 Prague 2, Czech Republic
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Cloy JM, Farmer JG, Graham MC, MacKenzie AB. Scottish peat bog records of atmospheric vanadium deposition over the past 150 years: comparison with other records and emission trends. ACTA ACUST UNITED AC 2011; 13:58-65. [DOI: 10.1039/c0em00492h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rothwell JJ, Taylor KG, Chenery SRN, Cundy AB, Evans MG, Allott TEH. Storage and behavior of As, Sb, Pb, and Cu in ombrotrophic peat bogs under contrasting water table conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:8497-8502. [PMID: 20977201 DOI: 10.1021/es101150w] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Concentration depth profiles and inventories of solid-phase As, Sb, Pb, and Cu were determined in ²¹⁰Pb-dated cores from an ombrotrophic peat bog in northwest England. Cores were collected from the peat dome and adjacent to an eroding gully. Down-core distributions of As, Sb, Pb, and Cu in the dome core are almost identical. The water table is close to the dome surface with only short-term draw-down. Under these conditions, As, Sb, Pb, and Cu are immobile, allowing the reconstruction of trends in historical contaminant deposition. The peak in atmospheric deposition of As, Sb, Pb, and Cu (4.59, 2.78, 147, and 26.7 mg m⁻² y⁻¹, respectively) occurred during the late 19th century. Stable Pb isotope ratios reveal that Pb deposition during this period was from indigenous and foreign sources. The mean water table is much lower at the gully edge, and there are pronounced interannual fluctuations. These conditions have not affected the integrity of the Pb and Cu records but have caused postdepositional mobilization and redistribution of As and Sb. Cumulative inventories show significant loss of As and Sb at the gully edge site. Long-term water table draw-down in ombrotrophic peat bogs has the potential to alter the geochemistry and fate of previously deposited As and Sb.
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Affiliation(s)
- James J Rothwell
- Upland Environments Research Unit, School of Environment and Development, The University of Manchester, Manchester M13 9PL, UK.
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29
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Novak M, Erbanova L, Fottova D, Voldrichova P, Prechova E, Blaha V, Veselovsky F, Krachler M. Increasing arsenic concentrations in runoff from 12 small forested catchments (Czech Republic, Central Europe): patterns and controls. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:3614-3622. [PMID: 20494405 DOI: 10.1016/j.scitotenv.2010.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 04/09/2010] [Accepted: 04/11/2010] [Indexed: 05/29/2023]
Abstract
The 40-year long period of heavy industrialization in Central Europe (1950-1990) was accompanied by burning of arsenic-rich lignite in thermal power plants, and accumulation of anthropogenic arsenic in forest soils. There are fears that retreating acidification may lead to arsenic mobilization into drinking water, caused by competitive ligand exchange. We present monthly arsenic concentrations in surface runoff from 12 headwater catchments in the Czech Republic for a period of 13 years (1996-2008). The studied area was characterized by a north-south gradient of decreasing pollution. Acidification, caused mainly by SOx and NOx emissions from power plants, has been retreating since 1987. Between 1996 and 2003, maximum arsenic concentrations in runoff did not change, and were < 1 ppb in the rural south and < 2 ppb in the industrial north. During the subsequent two years, 2004-2005, maximum arsenic concentrations in runoff increased, reaching 60% of the drinking water limit (10 ppb). Starting in 2006, maximum arsenic concentrations returned to lower values at most sites. We discuss three possible causes of the recent arsenic concentration maximum in runoff. We rule out retreating acidification and a pulse of high industrial emission rates as possible controls. The pH of runoff has not changed since 1996, and is still too low (<6.5) at most sites for an As-OH(-) ligand exchange to become significant. Elevated arsenic concentrations in runoff in 2004-2005 may reflect climate change through changing hydrological conditions at some, but not all sites. Dry conditions may result in elevated production of DOC and sulfur oxidation in the soil. Subsequent wet conditions may be accompanied by acidification leading to faster dissolution of arsenic-bearing sulfides, dissolution of arsenic-bearing Fe-oxyhydroxides, and elevated transport of arsenic sorbed on organic matter. Anaerobic domains exist in normally well-aerated upland soils for hours-to-days following precipitation events.
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Affiliation(s)
- Martin Novak
- Department of Geochemistry, Czech Geological Survey, Geologicka 6, 15200 Prague 5, Czech Republic.
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Deppe M, McKnight DM, Blodau C. Effects of short-term drying and irrigation on electron flow in mesocosms of a northern bog and an alpine fen. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:80-86. [PMID: 20039737 DOI: 10.1021/es901669z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Methane emissions and element mobility in wetlands are controlled by soil moisture and redox conditions. We manipulated soil moisture by weekly drying and irrigation of mesocosms of peat from a bog and iron and sulfur rich fen. Water table changed more strongly in the decomposed fen peat ( approximately 11 cm) than in the fibric bog peat ( approximately 5 cm), where impacts on redox processes were larger due to larger change in air filled porosity. Methanogenesis was partly decoupled from acetogenesis and acetate accumulated up to 5.6 mmol L(-1) in the fen peat after sulfate was depleted. Irrigation and drying led to rapid redox-cycles with sulfate, hydrogen sulfide, nitrate, and methane being produced and consumed on the scale of days, contributing substantially to the total electron flow and suggesting short-term resilience of the microbial community to intermittent aeration. Anaerobic CO2 production was partly balanced by methanogenesis (0-34%), acetate fermentation (0-86%), and sulfate reduction (1-30%) in the bog peat. In the fen peat unknown electron acceptors and aerenchymatic oxygen influx apparently drove respiration. The results suggest that regular rainfall and subsequent drying may lead to local oxidation-reduction cycles that substantially influence electron flow in electron acceptor poor wetlands.
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Affiliation(s)
- Marianna Deppe
- Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, Colorado 80309, USA
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Colauto NB, da Silveira AR, da Eira AF, Linde GA. Alternative to peat for Agaricus brasiliensis yield. BIORESOURCE TECHNOLOGY 2010; 101:712-716. [PMID: 19735998 DOI: 10.1016/j.biortech.2009.08.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 08/06/2009] [Accepted: 08/07/2009] [Indexed: 05/28/2023]
Abstract
Casing layer is one of the most important components of Agaricus spp. production and it directly affects mushroom productivity, size and mass. The aim of this study was to evaluate potential raw materials as a casing layer and their effect on Agaricus brasiliensis productivity. Raw materials from Brazil with potential use were selected and characterized, and the most promising ones were tested as casing layers for mushroom yield. Evaluated raw materials included lime schist, vermiculite, eucalyptus sawdust, sand, São Paulo peat, Santa Catarina peat, subsoil and charcoal. Particle size, porosity and water absorption in relation to mushroom yield for casing layers were determined. Lime schist, an alternate casing layer to peat, is presented and the effects of the casing layer on the mushroom yield are discussed.
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Affiliation(s)
- Nelson Barros Colauto
- Universidade Paranaense, Laboratório de Biologia Molecular, CEP 87.502-210, Umuarama-PR, Brazil
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