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Zhou F, Xu Q, Chen Y, Zhang W, Qiu R. Iodine enrichment in the groundwater in South China and its hydrogeochemical control. J Environ Sci (China) 2024; 142:226-235. [PMID: 38527888 DOI: 10.1016/j.jes.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 03/27/2024]
Abstract
In North China, iodine-rich groundwater has been extensively studied, but few in South China. This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamination sources. The results revealed that the average concentration of iodine in groundwater was 890 µg/L, with a maximum concentration of 6350 µg/L, exceeding the permitted levels recommended by the World Health Organization (5-300 µg/L). Notably, the enrichment of iodide occurred in acidic conditions (pH = 6.6) and a relatively low Eh environment (Eh = 198.4 mV). Pearson correlation and cluster analyses suggested that the enrichment of iodide could be attributed to the intensified redox process involving Mn(II), iodine (I2), or iodate (IO3-) in the soil. The strong affinity between Mn(II) and I2/IO3- facilitated their interaction, resulting in the formation and mobilization of I- from the soil to the groundwater. Leaching experiments further confirmed that reducing substances (such as sodium sulfides, ascorbic acids, and fulvic acids) in the soil with low dissolved oxygen (DO) levels (< 1.0 mg/L) enhanced the dissolution of iodine species. Conversely, higher DO content (> 3.8 mg/L) promoted the oxidation of I- into I2 or IO3-, leading to its stabilization. This research provides new insights into the characteristics and mechanisms of I- enrichment in groundwater in South China, and emphasizes the significance of the redox reactions involving Mn(II) and I2/IO3-, as well as the influence of soil properties in regulating the occurrence and transportation of iodine species within groundwater systems.
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Affiliation(s)
- Fengping Zhou
- Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology, Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Qianting Xu
- Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology, Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuyun Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology, Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Weihua Zhang
- Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology, Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Shenzhen Research Institute, Sun Yat-sen University, Shenzhen 518057, China.
| | - Rongliang Qiu
- Guangdong Provincial Key Laboratory of Environmental Pollution and Remediation Technology, Guangdong Provincial Engineering Research Center for Heavy Metal Contaminated Soil Remediation, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, School of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
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Szlamkowicz IB, Colon Roman LM, Hunley LM, Carroll AB, Pereira BB, Anagnostopoulos VA. Structural contributions of different manganese oxide minerals on the redox transformations and proliferation of iodine. CHEMOSPHERE 2023; 339:139631. [PMID: 37487972 DOI: 10.1016/j.chemosphere.2023.139631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 07/26/2023]
Abstract
The redox capabilities of birnessite minerals are contingent upon the physical characteristics of the solid, indicating that different allotropes have various reactivities. Here, the role of these structural differences on the oxidation of iodine, a risk driving environmental contaminant in several federal complexes, was investigated. The mechanism of which can be seen here, with one of the minerals of study, acid birnessite. The pH range chosen for this study was pH 5-6. Throughout the experiments it was seen that the average oxidation state (AOS) had the greatest contribution to the differences in redox capabilities of the various birnessite minerals. Several trends were observed throughout this study: as AOS decreased, oxidation of iodide (I-) increased; as specific surface area (SSA) increased, the sorption of iodate (IO3-) increased. Additional experiments were conducted at trace levels of iodine, to better model environmental conditions. In that case, a one-step conversion of I- to IO3- occurred, to a greater extent than under artificially elevated concentrations.
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Affiliation(s)
- Ilana B Szlamkowicz
- Department of Chemistry, University of Central Florida, 4353 Scorpius Str., Orlando, FL, 32816, USA
| | - Lisa M Colon Roman
- Department of Chemistry, University of Central Florida, 4353 Scorpius Str., Orlando, FL, 32816, USA
| | - Lucy M Hunley
- Department of Chemistry, University of Central Florida, 4353 Scorpius Str., Orlando, FL, 32816, USA
| | - Austin B Carroll
- Department of Chemistry, University of Central Florida, 4353 Scorpius Str., Orlando, FL, 32816, USA
| | - Brinly B Pereira
- Department of Chemistry, University of Central Florida, 4353 Scorpius Str., Orlando, FL, 32816, USA
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Du J, Kim K, Son S, Pan D, Kim S, Choi W. MnO 2-Induced Oxidation of Iodide in Frozen Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5317-5326. [PMID: 36952586 DOI: 10.1021/acs.est.3c00604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Metal oxides play a critical role in the abiotic transformation of iodine species in natural environments. In this study, we investigated iodide oxidation by manganese dioxides (β-MnO2, γ-MnO2, and δ-MnO2) in frozen and aqueous solutions. The heterogeneous reaction produced reactive iodine (RI) in the frozen phase, and the subsequent thawing of the frozen sample induced the gradual transformation of in situ-formed RI to iodate or iodide, depending on the types of manganese dioxides. The freezing-enhanced production of RI was observed over the pH range of 5.0-9.0, but it decreased with increasing pH. Fulvic acid (FA) can be iodinated by I-/MnO2 in aqueous and frozen solutions. About 0.8-8.4% of iodide was transformed to organoiodine compounds (OICs) at pH 6.0-7.8 in aqueous solution, while higher yields (10.4-17.8%) of OICs were obtained in frozen solution. Most OICs generated in the frozen phase contained one iodine atom and were lignin-like compounds according to Fourier transform ion cyclotron resonance/mass spectrometry analysis. This study uncovers a previously unrecognized production pathway of OICs under neutral conditions in frozen environments.
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Affiliation(s)
- Juanshan Du
- KENTECH Institute for Environmental & Climate Technology, Korea Institute of Energy Technology (KENTECH), Naju 58330, Korea
| | - Kitae Kim
- Korea Polar Research Institute (KOPRI), Incheon 21990, Korea
| | - Seungwoo Son
- Department of Chemistry, Kyungpook National University, Daegu 41566, Korea
| | - Donglai Pan
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Sunghwan Kim
- Department of Chemistry, Kyungpook National University, Daegu 41566, Korea
| | - Wonyong Choi
- KENTECH Institute for Environmental & Climate Technology, Korea Institute of Energy Technology (KENTECH), Naju 58330, Korea
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Roulier M, Carasco L, Orjollet D, Bueno M, Pannier F, Le Hécho I, Nicolas M, Coppin F. Iodine distribution and volatilization in contrasting forms of forest humus during a laboratory incubation experiment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 248:106872. [PMID: 35430501 DOI: 10.1016/j.jenvrad.2022.106872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 03/19/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Radionuclides 129I (t1/2 = 15.7 × 106 years) and 131I (t1/2 = 8.02 days) are both introduced into the environment as a result of nuclear human activities. Environmental transfer pathways and fluxes between and within ecosystems are essential information for risk assessment. In forest ecosystems, humus degradation over time could result in re-mobilization and then downward migration and/or volatilization of intercepted 129I. In order to estimate the scale of these processes, humus (mull and moder forms) sampled under deciduous and coniferous forests were spiked with 125I- (t1/2 = 59.4 days), as a surrogate for 129I, in order to study the evolution of its water-soluble and organic fractions as well as the volatilization rate during humus degradation at laboratory scale. To our knowledge, this is the first time that interactions between iodine and contrasting forms of forest humus have been investigated. The evolution of native stable iodine (127I) pools in unspiked humus was also studied. The nature of the humus' organic matter appears to be a factor that impacts on the proportions of water-soluble and organic fractions of iodine and on their evolution. Iodine-125 was mainly organically bound (fraction for mulls and moders: ∼54-59 and 41-49%, respectively) and no clear evolution was observed within the 4-month incubation period. A large decrease in 125I water-solubility occurred, being more marked for mull (from ∼14-32 to 3-7%) than for moder (from ∼21-37 to 7-19%) humus. By contrast, a significant fraction was not extractible (∼38-43%) and varied in inverse proportion to the water-soluble fraction, suggesting a stabilization of iodine in humus after wet deposit. The nature of the humus organic matter also impacted on 125I volatilization. Although of the same order of magnitude, the total volatilization of 125I was higher for moders (∼0.039-0.323%) than for mulls (∼0.015-0.023%) within the 4-month incubation period. Volatilization rates for mulls were correlated with the water-soluble fraction, implying that volatilization of 125I could occur from the humus solution. Our results showed that humus is thus a zone of iodine accumulation by association with organic matter and that potential losses by lixiviation are significantly more important compared to volatilization.
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Affiliation(s)
- Marine Roulier
- Institute of Radiological Protection and Nuclear Safety IRSN, PSE-ENV/SRTE/LR2T, CE Cadarache, 13115, Saint Paul les Durance Cedex, France; CNRS/Univ. Pau & Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000, Pau, France.
| | - Loïc Carasco
- Institute of Radiological Protection and Nuclear Safety IRSN, PSE-ENV/SRTE/LR2T, CE Cadarache, 13115, Saint Paul les Durance Cedex, France.
| | - Daniel Orjollet
- Institute of Radiological Protection and Nuclear Safety IRSN, PSE-ENV/SRTE/LR2T, CE Cadarache, 13115, Saint Paul les Durance Cedex, France.
| | - Maïté Bueno
- CNRS/Univ. Pau & Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000, Pau, France.
| | - Florence Pannier
- CNRS/Univ. Pau & Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000, Pau, France.
| | - Isabelle Le Hécho
- CNRS/Univ. Pau & Pays de l'Adour/E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000, Pau, France.
| | - Manuel Nicolas
- Office National des Forêts ONF, Direction forêts et risques naturels, Département recherche, développement, innovation, Boulevard de Constance, 77300, Fontainebleau, France.
| | - Frédéric Coppin
- Institute of Radiological Protection and Nuclear Safety IRSN, PSE-ENV/SRTE/LR2T, CE Cadarache, 13115, Saint Paul les Durance Cedex, France.
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Du J, Kim K, Min DW, Choi W. Freeze-Thaw Cycle-Enhanced Transformation of Iodide to Organoiodine Compounds in the Presence of Natural Organic Matter and Fe(III). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1007-1016. [PMID: 34967617 DOI: 10.1021/acs.est.1c06747] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The formation of organoiodine compounds (OICs) is of great interest in the natural iodine cycle as well as water treatment processes. Herein, we report a pathway of OIC formation that reactive iodine (RI) and OICs are produced from iodide oxidation in the presence of Fe(III) and natural organic matter (NOM) in frozen solution, whereas their production is insignificant in aqueous solution. Moreover, thawing the frozen solution induces the further production of OICs. A total of 352 OICs are detected by Fourier transform ion cyclotron resonance mass spectrometry in the freeze-thaw cycled reactions of Fe(III)/I-/humic acid solution, which are five times as many as OICs in aqueous reactions. Using model organic compounds instead of NOM, aromatic compounds (e.g., phenol, aniline, o-cresol, and guaiacol) induce higher OIC formation yields (10.4-18.6%) in the freeze-thaw Fe(III)/I- system than those in aqueous (1.1-2.1%) or frozen (2.7-7.6%) solutions. In the frozen solution, the formation of RI is enhanced, but its further reaction with NOM is hindered. Therefore, the freeze-thaw cycle in which RI is formed in the frozen media and the resulting RI is consumed by reaction with NOM in the subsequently thawed solution is more efficient in producing OICs than the continuous reaction in frozen solution.
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Affiliation(s)
- Juanshan Du
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Kitae Kim
- Korea Polar Research Institute (KOPRI), Incheon 21990, Korea
| | - Dae Wi Min
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Wonyong Choi
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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Duborská E, Balíková K, Matulová M, Zvěřina O, Farkas B, Littera P, Urík M. Production of Methyl-Iodide in the Environment. Front Microbiol 2021; 12:804081. [PMID: 35003036 PMCID: PMC8733467 DOI: 10.3389/fmicb.2021.804081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Iodine is an essential micronutrient for most of the living beings, including humans. Besides its indispensable role in animals, it also plays an important role in the environment. It undergoes several chemical and biological transformations resulting in the production of volatile methylated iodides, which play a key role in the iodine's global geochemical cycle. Since it can also mitigate the process of climate change, it is reasonable to study its biogeochemistry. Therefore, the aim of this review is to provide information on its origin, global fluxes and mechanisms of production in the environment.
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Affiliation(s)
- Eva Duborská
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
| | - Katarína Balíková
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
| | - Michaela Matulová
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
| | - Ondřej Zvěřina
- Department of Public Health, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Bence Farkas
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
| | - Pavol Littera
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
| | - Martin Urík
- Faculty of Natural Sciences, Institute of Laboratory Research on Geomaterials, Comenius University in Bratislava, Bratislava, Slovakia
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Yu Y, Li G, Chen R, Shi B. Trihalomethanes formation enhanced by manganese chlorination and deposition in plastic drinking water pipes. WATER RESEARCH 2021; 204:117582. [PMID: 34474250 DOI: 10.1016/j.watres.2021.117582] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Residual manganese(II) in finished water undergoes further oxidation and deposition in drinking water distribution systems (DWDS), and Mn deposits can function as sites for accumulating organic and inorganic pollutants. This study aims to explore how Mn transformation and deposition affect the formation of disinfection byproducts (DBPs) in chlorinated DWDS, and trihalomethanes (THMs) was selected as a representative DBP. In a 100 μg/L Mn system, regulated THMs (chlorinated/bromated-THMs) increased by over 20% higher than Mn-free system after 150-day operation; when 50 μg/L iodide (I-) entered pipe systems after 150 days, iodinated THMs (I-THMs) in 100 μg/L Mn system increased by over 30% compared with Mn-free system. These promotions were attributed primarily to the accumulation of biomolecules and organic substances by tight and hard chlorinated Mn deposits. The residence of inactivated cells and the bridging role of surface Mn(III) in Mn deposits increased the quantity of THM precursors in DWDS. Furthermore, the rapid catalytic oxidation of Mn(II) by preformed Mn oxides (MnOx) inhibited the conversion of free iodine (HOI/OI-) to iodate, resulting in the generation of more I-THMs. This study provides new insights into the DBP risks caused by Mn in DWDS.
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Affiliation(s)
- Ying Yu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guiwei Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruya Chen
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baoyou Shi
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Li Y, He Z, Yang GP, Zou Y. Spatial distribution and biogeochemical cycling of methyl iodide in the Yellow Sea and the East China Sea during summer. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 276:116749. [PMID: 33639487 DOI: 10.1016/j.envpol.2021.116749] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/10/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Methyl iodide (CH3I) released from ocean is an important carrier of iodine, which plays an important role in ozone depletion in the atmosphere. Depletion of ozone has increased the amount of ultraviolet radiation that reaches the earth's surface and recent global warming has caused oceanic acidification as well as dust events, but how these environmental changes will affect CH3I concentration in the ocean is unclear. In this study, the spatial distributions and sources of CH3I in the atmosphere, seawater, and sediment porewater were measured in the Yellow Sea (YS) and the East China Sea (ECS) between June and July 2018. Higher concentrations in the atmosphere, seawater, and sediment were found in the YS than in the ECS, and surface seawater emissions were discovered to be the major contributors of atmospheric CH3I concentrations. Anthropogenic pollutants could explain significant spatial variation in the distribution of CH3I. High concentrations of CH3I in sediment porewater increased diffusion into bottom waters, with diffusive fluxes of 0.2-6.5 nmol m-2 d-1. Preliminary results during the in situ seawater incubation experiments showed that the photochemical production rate of CH3I ranged from 0.008 to 0.214 pmol L-1 h-1 under ultraviolet light, and an enhancement emission of CH3I from phytoplankton occurred with the addition of dust, while a reduction of CH3I appeared under lower pH conditions.
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Affiliation(s)
- Yan Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Zhen He
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Institute of Marine Chemistry, Ocean University of China, Qingdao, 266100, China
| | - Gui-Peng Yang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Institute of Marine Chemistry, Ocean University of China, Qingdao, 266100, China.
| | - Yawen Zou
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
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Li J, Wang Y, Xue X, Xie X, Siebecker MG, Sparks DL, Wang Y. Mechanistic insights into iodine enrichment in groundwater during the transformation of iron minerals in aquifer sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:140922. [PMID: 32736101 DOI: 10.1016/j.scitotenv.2020.140922] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
Long-term intake of groundwater with elevated iodine concentration can cause thyroid dysfunction in humans; however, little is known on the mechanisms controlling the fate of iodine in groundwater systems. In this study, the groundwater and aquifer sediment samples from the Datong basin, a geologic iodine-affected area, were collected to perform the batch incubation experiments to understand the release and enrichment of iodine in groundwater systems. The results showed that the groundwater from the deep confined aquifer had a total iodine concentration of 473 μg/L, higher than that of shallow groundwater, and iodide is the dominant species of iodine. The deep confined aquifer was characterized by the reducing conditions. Meanwhile, a higher ratio of Fe(II) to total Fe was observed in bulk deep aquifer sediments (59%) in comparison with that of shallow sediments (33%). The results of batch incubation experiments showed that during the reductive transformation of Fe minerals in shallow aquifer sediments, iodide concentration in solution was gradually increasing from 24.7 to 101.5 μg/L after 10 days. It suggests that the transformation of Fe minerals in aquifer sediments acts as a diver causing the release of iodine from sediment into groundwater, which was further supported by the features Fe K-edge EXAFS before and after the batch experiments. Moreover, the changes in iodine species from iodate or organic iodine into iodide during the release further promotes the release of sediment iodine, which was supported by the developed geochemical models. The prevalence of reducing condition in deep aquifer favors the enrichment of released iodide. This study provides new insights into the mechanisms of iodide enrichment observed in deep confined aquifer.
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Affiliation(s)
- Junxia Li
- State Key Laboratory of Biogeology and Environmental Geology & School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China.
| | - Yuting Wang
- State Key Laboratory of Biogeology and Environmental Geology & School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
| | - Xiaobin Xue
- State Key Laboratory of Biogeology and Environmental Geology & School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
| | - Xianjun Xie
- State Key Laboratory of Biogeology and Environmental Geology & School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China; Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, 430074 Wuhan, China.
| | - Matthew G Siebecker
- Environmental Soil Chemistry Group, Delaware Environmental Institute and Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, United States; Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, United States
| | - Donald L Sparks
- Environmental Soil Chemistry Group, Delaware Environmental Institute and Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, United States
| | - Yanxin Wang
- State Key Laboratory of Biogeology and Environmental Geology & School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
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10
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Bagwell CE, Zhong L, Wells JR, Mitroshkov AV, Qafoku NP. Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA. Front Microbiol 2019; 10:2460. [PMID: 31708909 PMCID: PMC6821650 DOI: 10.3389/fmicb.2019.02460] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/14/2019] [Indexed: 11/25/2022] Open
Abstract
Incomplete knowledge of environmental transformation reactions limits our ability to accurately inventory and predictably model the fate of radioiodine. The most prevalent chemical species of iodine include iodate (IO3−), iodide (I−), and organo-iodine. The emission of gaseous species could be a loss or flux term but these processes have not previously been investigated at radioiodine-impacted sites. We examined iodide methylation and volatilization for Hanford Site sediments from three different locations under native and organic substrate amended conditions at three iodide concentrations. Aqueous and gaseous sampling revealed methyl-iodide to be the only iodinated compound produced under biotic conditions. No abiotic transformations of iodide were measured. Methyl-iodide was produced by 52 out of 54 microcosms, regardless of prior exposure to iodine contamination or the experimental concentration. Interestingly, iodide volatilization activity was consistently higher under native (oligotrophic) Hanford sediment conditions. Carbon and nutrients were not only unnecessary for microbial activation, but supplementation resulted in >three-fold reduction in methyl-iodide formation. This investigation not only demonstrates the potential for iodine volatilization in deep, oligotrophic subsurface sediments at a nuclear waste site, but also emphasizes an important role for biotic methylation pathways to the long-term management and monitoring of radioiodine in the environment.
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Affiliation(s)
- Christopher E Bagwell
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
| | - Lirong Zhong
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
| | - Jacqueline R Wells
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
| | - Alexandre V Mitroshkov
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
| | - Nikolla P Qafoku
- Pacific Northwest National Laboratory, Earth Systems Science Division, Richland, WA, United States
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11
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Zhou S, Du Z, Li X, Zhang Y, He Y, Zhang Y. Degradation of methylene blue by natural manganese oxides: kinetics and transformation products. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190351. [PMID: 31417737 PMCID: PMC6689640 DOI: 10.1098/rsos.190351] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/12/2019] [Indexed: 05/06/2023]
Abstract
In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m2 g-1, it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4-8) and initial concentration of MB (10-50 mg l-1), but positively with the dosage of MnO x (1-5 g l-1). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.
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Affiliation(s)
| | | | | | | | - Yide He
- School of Environmental Science and Engineering, Nanjing Tech University, Pu Zhu Nan Lu 30, Nanjing 211800, People's Republic of China
| | - Yongjun Zhang
- School of Environmental Science and Engineering, Nanjing Tech University, Pu Zhu Nan Lu 30, Nanjing 211800, People's Republic of China
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Roulier M, Bueno M, Thiry Y, Coppin F, Redon PO, Le Hécho I, Pannier F. Iodine distribution and cycling in a beech (Fagus sylvatica) temperate forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:431-440. [PMID: 30025242 DOI: 10.1016/j.scitotenv.2018.07.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/27/2018] [Accepted: 07/03/2018] [Indexed: 06/08/2023]
Abstract
Radioiodine is of health concerns in case of nuclear events. Possible pathways and rates of flow are essential information for risk assessment. Forest ecosystems could influence the global cycle of long-lived radioiodine isotope (129I) with transfer processes similar to stable isotope (127I). Understanding iodine cycling in forest involves study of the ecosystem as a whole. In this context, we determined the 127I contents and distribution in soil, tree compartments and atmospheric inputs during a three years in situ monitoring of a temperate beech forest stand. The iodine cycle was first characterized in terms of stocks by measuring its concentrations in: tree, litterfall, humus, soil, rainfall, throughfall, stemflow and soil solutions. Main annual fluxes (requirement, uptake and internal transfers) and forest input-output budget were also estimated using conceptual model calculations. Our findings show that: (i) soil is the main I reservoir accounting for about 99.9% of ecosystem total stock; (ii) iodine uptake by tree represents a minor fraction of the available pool in soil (<0.2%); (iii) iodine allocation between tree compartments involves low immobilization in wood and restricted location in the roots; (iv) translocation of excess iodine towards senescing foliage appears as an elimination process for trees, and (v) litterfall is a major pathway in the I biological cycling. In our soil conditions, the input - output budget shows that the ecosystem behaves as a potential source of I for groundwater.
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Affiliation(s)
- Marine Roulier
- Institute of Radioecological Protection and Nuclear Safety (IRSN), PSE-ENV, SRTE, LR2T, CE Cadarache, 13115 Saint Paul les Durance Cedex, France; CNRS/Univ. Pau & Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000 Pau, France.
| | - Maïté Bueno
- CNRS/Univ. Pau & Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000 Pau, France.
| | - Yves Thiry
- Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex, France.
| | - Frédéric Coppin
- Institute of Radioecological Protection and Nuclear Safety (IRSN), PSE-ENV, SRTE, LR2T, CE Cadarache, 13115 Saint Paul les Durance Cedex, France.
| | - Paul-Olivier Redon
- Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex, France.
| | - Isabelle Le Hécho
- CNRS/Univ. Pau & Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000 Pau, France.
| | - Florence Pannier
- CNRS/Univ. Pau & Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, UMR 5254, Avenue du Président Angot, 64000 Pau, France.
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Shin J, von Gunten U, Reckhow DA, Allard S, Lee Y. Reactions of Ferrate(VI) with Iodide and Hypoiodous Acid: Kinetics, Pathways, and Implications for the Fate of Iodine during Water Treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7458-7467. [PMID: 29856214 DOI: 10.1021/acs.est.8b01565] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Oxidative treatment of iodide-containing waters can form toxic iodinated disinfection byproducts (I-DBPs). To better understand the fate of iodine, kinetics, products, and stoichiometries for the reactions of ferrate(VI) with iodide (I-) and hypoiodous acid (HOI) were determined. Ferrate(VI) showed considerable reactivities to both I- and HOI with higher reactivities at lower pH. Interestingly, the reaction of ferrate(VI) with HOI ( k = 6.0 × 103 M-1 s-1 at pH 9) was much faster than with I- ( k = 5.6 × 102 M-1 s-1 at pH 9). The main reaction pathway during treatment of I--containing waters was the oxidation of I- to HOI and its further oxidation to IO3- by ferrate(VI). However, for pH > 9, the HOI disproportionation catalyzed by ferrate(VI) became an additional transformation pathway forming I- and IO3-. The reduction of HOI by hydrogen peroxide, the latter being produced from ferrate(VI) decomposition, also contributes to the I- regeneration in the pH range 9-11. A kinetic model was developed that could well simulate the fate of iodine in the ferrate(VI)-I- system. Overall, due to a rapid oxidation of I- to IO3- with short-lifetimes of HOI, ferrate(VI) oxidation appears to be a promising option for I-DBP mitigation during treatment of I--containing waters.
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Affiliation(s)
- Jaedon Shin
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology (GIST) , Gwangju 61005 , Republic of Korea
- Curtin Water Quality Research Centre, Department of Chemistry , Curtin University , GPO Box U1987 , Perth , Western Australia 6845 , Australia
| | - Urs von Gunten
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133 , CH-8600 Duebendorf , Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC) , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - David A Reckhow
- Department of Civil and Environmental Engineering , University of Massachusetts , Amherst Massachusetts 01003 , United States
| | - Sebastien Allard
- Curtin Water Quality Research Centre, Department of Chemistry , Curtin University , GPO Box U1987 , Perth , Western Australia 6845 , Australia
| | - Yunho Lee
- School of Earth Sciences and Environmental Engineering , Gwangju Institute of Science and Technology (GIST) , Gwangju 61005 , Republic of Korea
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Hao Z, Wang J, Yin Y, Cao D, Liu J. Abiotic formation of organoiodine compounds by manganese dioxide induced iodination of dissolved organic matter. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 236:672-679. [PMID: 29438953 DOI: 10.1016/j.envpol.2018.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 06/08/2023]
Abstract
Iodination of dissolved organic matter (DOM) initiated by manganese oxide may represent an important source of organoiodine compounds (OICs) for iodide-containing waters. Here, Suwannee River natural organic matter was selected as model DOM, the OICs formation in simulated freshwater samples from iodinated DOM induced by manganese oxide (δ-MnO2) was investigated at different pHs and concentrations of iodide and δ-MnO2 by using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). While no OIC was observed in DOM control samples without δ-MnO2, hundreds of OICs were detected in the presence of δ-MnO2, suggesting the enhanced role of δ-MnO2 played in DOM iodination. The relative abundance was defined as the value of dividing the peak intensity of OICs by the highest m/z peak intensity constantly occurred in each mass spectrum, and selected as a parameter for partly reflecting the real level of OICs. The relative abundance of most OICs were around or greater than 1%, and several OICs with higher relative abundance were identified as diiodo-5-hydroxy-4-cyclopentene-1,3-dione, diiodomethane and diiodoacetic acid. The numbers of the formed OICs increased with the increase concentrations of iodide/δ-MnO2 and the decrease of pH, and nearly all OICs formed at lower levels of iodide/δ-MnO2 and/or higher pH were overlapped by that at higher levels of iodide/δ-MnO2 and/or lower pH, indicating the reliability of FT-ICR MS analysis techniques and data processing method. The OICs were formed mainly from the iodination of typical lignin-like and tannin-like compounds, as well as the precursor compounds with higher relative abundance through substitution reactions. Our findings demonstrate that the OICs formation by δ-MnO2-initiated DOM iodination should receive more attention and the concentration, exact structure and toxicity of the OICs need to be further investigated.
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Affiliation(s)
- Zhineng Hao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
| | - Juan Wang
- Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Yongguang Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
| | - Dong Cao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China
| | - Jingfu Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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15
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Li J, Zhou H, Wang Y, Xie X, Qian K. Sorption and speciation of iodine in groundwater system: The roles of organic matter and organic-mineral complexes. JOURNAL OF CONTAMINANT HYDROLOGY 2017; 201:39-47. [PMID: 28495233 DOI: 10.1016/j.jconhyd.2017.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 04/06/2017] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
Characterizing the properties of main host of iodine in soil/sediment and the geochemical behaviors of iodine species are critical to understand the mechanisms of iodine mobilization in groundwater systems. Four surface soil and six subsurface sediment samples were collected from the iodine-affected area of Datong basin in northern China to conduct batch experiments and to evaluate the effects of NOM and/or organic-mineral complexes on iodide/iodate geochemical behaviors. The results showed that both iodine contents and kf-iodate values had positive correlations with solid TOC contents, implying the potential host of NOM for iodine in soil/sediment samples. The results of chemical removal of easily extracted NOM indicated that the NOM of surface soils is mainly composed of surface embedded organic matter, while sediment NOM mainly occurs in the form of organic-mineral complexes. After the removal of surface sorbed NOM, the decrease in kf-iodate value of treated surface soils indicates that surface sorbed NOM enhances iodate adsorption onto surface soil. By contrast, kf-iodate value increases in several H2O2-treated sediment samples, which was considered to result from exposed rod-like minerals rich in Fe/Al oxyhydroxide/oxides. After chemical removal of organic-mineral complexes, the lowest kf-iodate value for both treated surface soils and sediments suggests the dominant role of organic-mineral complexes on controlling the iodate geochemical behavior. In comparison with iodate, iodide exhibited lower affinities on all (un)treated soil/sediment samples. The understanding of different geochemical behaviors of iodine species helps to explain the occurrence of high iodine groundwater with iodate and iodide as the main species in shallow (oxidizing conditions) and deep (reducing conditions) groundwater.
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Affiliation(s)
- Junxia Li
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
| | - Hailing Zhou
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
| | - Yanxin Wang
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China.
| | - Xianjun Xie
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
| | - Kun Qian
- State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, China
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Allard S, Gutierrez L, Fontaine C, Croué JP, Gallard H. Organic matter interactions with natural manganese oxide and synthetic birnessite. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 583:487-495. [PMID: 28126279 DOI: 10.1016/j.scitotenv.2017.01.120] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 06/06/2023]
Abstract
Redox reactions of inorganic and organic contaminants on manganese oxides have been widely studied. However, these reactions are strongly affected by the presence of natural organic matter (NOM) at the surface of the manganese oxide. Interestingly, the mechanism behind NOM adsorption onto manganese oxides remains unclear. Therefore, in this study, the adsorption kinetics and equilibrium of different NOM isolates to synthetic manganese oxide (birnessite) and natural manganese oxide (Mn sand) were investigated. Natural manganese oxide is composed of both amorphous and well-crystallised Mn phases (i.e., lithiophorite, birnessite, and cryptomelane). NOM adsorption on both manganese oxides increased with decreasing pH (from pH7 to 5), in agreement with surface complexation and ligand exchange mechanisms. The presence of calcium enhanced the rate of NOM adsorption by decreasing the electrostatic repulsion between NOM and Mn sand. Also, the adsorption was limited by the diffusion of NOM macromolecules through the Mn sand pores. At equilibrium, a preferential adsorption of high molecular weight molecules enriched in aromatic moieties was observed for both the synthetic and natural manganese oxide. Hydrophobic interactions may explain the adsorption of organic matter on manganese oxides. The formation of low molecular weight UV absorbing molecules was detected with the synthetic birnessite, suggesting oxidation and reduction processes occurring during NOM adsorption. This study provides a deep insight for both environmental and engineered systems to better understand the impact of NOM adsorption on the biogeochemical cycle of manganese.
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Affiliation(s)
- Sébastien Allard
- Institut de Chimie des Milieux et des Matériaux IC2MP UMR 7285 CNRS Université de Poitiers, ENSIP, 1 rue Marcel Doré TSA 41105, 86 073 Poitiers Cedex 9, France; Curtin Water Quality Research Center, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Leonardo Gutierrez
- Curtin Water Quality Research Center, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; Facultad del Mar y Medio Ambiente, Universidad del Pacifico, Guayaquil, Ecuador
| | - Claude Fontaine
- Institut de Chimie des Milieux et des Matériaux IC2MP- UMR 7285 CNRS Université de Poitiers, Equipe Hydrasa, 5 rue Albert Turpain, 86022 Poitiers Cedex, France
| | - Jean-Philippe Croué
- Institut de Chimie des Milieux et des Matériaux IC2MP UMR 7285 CNRS Université de Poitiers, ENSIP, 1 rue Marcel Doré TSA 41105, 86 073 Poitiers Cedex 9, France; Curtin Water Quality Research Center, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - Hervé Gallard
- Institut de Chimie des Milieux et des Matériaux IC2MP UMR 7285 CNRS Université de Poitiers, ENSIP, 1 rue Marcel Doré TSA 41105, 86 073 Poitiers Cedex 9, France
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17
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Guan C, Jiang J, Luo C, Pang S, Jiang C, Ma J, Jin Y, Li J. Transformation of Iodide by Carbon Nanotube Activated Peroxydisulfate and Formation of Iodoorganic Compounds in the Presence of Natural Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:479-487. [PMID: 27982571 DOI: 10.1021/acs.est.6b04158] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, we interestingly found that peroxydisulfate (PDS) could be activated by a commercial multiwalled carbon nanotube (CNT) material via a nonradical pathway. Iodide (I-) was quickly and almost completely oxidized to hypoiodous acid (HOI) in the PDS/CNT system over the pH range of 5-9, but the further transformation to iodate (IO3-) was negligible. A kinetic model was proposed, which involved the formation of reactive PDS-CNT complexes, and then their decomposition into sulfate anion (SO42-) via inner electron transfer within the complexes or by competitively reacting with I-. Several influencing factors (e.g., PDS and CNT dosages, and solution pH) on I- oxidation kinetics by this system were evaluated. Humic acid (HA) decreased the oxidation kinetics of I-, probably resulting from its inhibitory effect on the interaction between PDS and CNT to form the reactive complexes. Moreover, adsordable organic iodine compounds (AOI) as well as specific iodoform and iodoacetic acid were appreciably produced in the PDS/CNT/I- system with HA. These results demonstrate the potential risk of producing toxic iodinated organic compounds in the novel PDS/CNT oxidation process developed very recently, which should be taken into consideration before its practical application in water treatment.
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Affiliation(s)
- Chaoting Guan
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
| | - Jin Jiang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
| | - Congwei Luo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
| | - Suyan Pang
- Key Laboratory of Green Chemical Engineering and Technology of College of Heilongjiang Province, College of Chemical and Environmental Engineering, Harbin University of Science and Technology , Harbin 150040, China
| | - Chengchun Jiang
- School of Civil and Environmental Engineering, Shenzhen Polytechnic , Shenzhen 518055, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
| | - Yixin Jin
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
| | - Juan Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, 150090, China
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Huguet M, Simon V, Gallard H. Transformation of paracetamol into 1,4-benzoquinone by a manganese oxide bed filter. JOURNAL OF HAZARDOUS MATERIALS 2014; 271:245-51. [PMID: 24632488 DOI: 10.1016/j.jhazmat.2014.02.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/31/2014] [Accepted: 02/11/2014] [Indexed: 05/13/2023]
Abstract
This study investigates the transformation of paracetamol (PRC) by a granular manganeseoxide in a column bed reactor. Paracetamol was quantitatively transformed into p-benzoquinone(BZQ) for empty bed residence times (EBRT) <5 min at pH 6.0. For 5mM MOPS (3-morpholinopropane-1-sulfonic acid) and pH 7.0, the mean removal yield of PRC was 77% for initial PRC concentrations ranging from 0.1 to 50 μM. Conversion of PRC and formation of BZQ decreased when pH increased from 6 to 8. Dimer of PRC was observed at pH 7.0, which could explain the lower conversion into BZQ when pH increased. The presence of organic buffer MOPS and natural organic matter (NOM) reduced the oxidation of PRC because of competition reactions for active sites. The formation of the toxic BZQ metabolite was reduced in presence of NOM because of cross-coupling reactions between phenoxyl radicals and NOM. Results suggest that manganese oxide bed filter can be used to remove pharmaceutical compounds including phenolic moiety in their structure.
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Affiliation(s)
- Mélissa Huguet
- Université de Poitiers - CNRS UMR 7285 IC2MP - ENSIP, 1 rue Marcel Doré, Poitiers Cedex 86022, France.
| | - Virginie Simon
- Université de Poitiers - CNRS UMR 7285 IC2MP - ENSIP, 1 rue Marcel Doré, Poitiers Cedex 86022, France.
| | - Hervé Gallard
- Université de Poitiers - CNRS UMR 7285 IC2MP - ENSIP, 1 rue Marcel Doré, Poitiers Cedex 86022, France.
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Allard S, Gallard H. Abiotic formation of methyl iodide on synthetic birnessite: a mechanistic study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 463-464:169-175. [PMID: 23803501 DOI: 10.1016/j.scitotenv.2013.05.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 05/20/2013] [Accepted: 05/24/2013] [Indexed: 06/02/2023]
Abstract
Methyl iodide is a well-known volatile halogenated organic compound that contributes to the iodine content in the troposphere, potentially resulting in damage to the ozone layer. Most methyl iodide sources derive from biological activity in oceans and soils with very few abiotic mechanisms proposed in the literature. In this study we report that synthetic manganese oxide (birnessite δ-MnO2) can catalyze the formation of methyl iodide in the presence of natural organic matter (NOM) and iodide. Methyl iodide formation was only observed at acidic pH (4-5) where iodide is oxidized to iodine and NOM is adsorbed on δ-MnO2. The effect of δ-MnO2, iodide and NOM concentrations, nature of NOM and ionic strength was investigated. High concentrations of methyl iodide were formed in experiments conducted with the model compound pyruvate. The Lewis acid property of δ-MnO2 leads to a polarization of the iodine molecule, and catalyzes the reaction with natural organic matter. As manganese oxides are strong oxidants and are ubiquitous in the environment, this mechanism could significantly contribute to the global atmospheric input of iodine.
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Affiliation(s)
- Sébastien Allard
- Ecole Nationale Supérieure d'Ingénieurs de Poitiers - Université de Poitiers, Institut de Chimie des Milieux et des Matériaux UMR 7285, 1, rue Marcel Doré, 86022 Poitiers Cedex, France.
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Huguet M, Deborde M, Papot S, Gallard H. Oxidative decarboxylation of diclofenac by manganese oxide bed filter. WATER RESEARCH 2013; 47:5400-8. [PMID: 23850215 DOI: 10.1016/j.watres.2013.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 06/07/2013] [Accepted: 06/08/2013] [Indexed: 05/13/2023]
Abstract
Diclofenac (DCF) was eliminated by fast chemical oxidation on natural manganese oxide in a column reactor. Identification of transformation by-products of DCF by HPLC-UV-MS(n) gave evidence of decarboxylation, iminoquinone formation and dimerization. The fast oxidation of DCF is also accompanied by a strong adsorption of organic carbon that was explained by the sorption of dimer products on the surface of manganese oxide. Decarboxylation and dimerization increased the hydrophobic interactions with manganese oxide and reduced the presence of potentially toxic by-products in the effluent. The rate of oxidation was first order with respect to DCF and was slowed down by the presence of organic buffer MOPS (3-morpholinopropane-1-sulfonic acid). The first order rate constant in absence of MOPS was extrapolated by considering a surface site-binding model and MOPS as a co-adsorbate. The rate constant was 0.818 min(-1) at pH 7 and 10 mM NaCl corresponding to empty bed residence time of 50 s only for 50% removal of DCF. Rate constants increased when pH decreased from pH 8.0 to 6.5 and when ionic strength increased. Manganese oxide bed filter can be considered as an alternative treatment for polishing waste water effluent or for remediation of contaminated groundwater.
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Affiliation(s)
- Mélissa Huguet
- Université de Poitiers, CNRS UMR 7285 IC2MP, ENSIP, 1 rue Marcel Doré, 86022 Poitiers Cedex, France.
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Li J, Wang Y, Xie X, Zhang L, Guo W. Hydrogeochemistry of high iodine groundwater: a case study at the Datong Basin, northern China. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2013; 15:848-859. [PMID: 23478640 DOI: 10.1039/c3em30841c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
High iodine concentrations in groundwater have seldom been reported and there have been few systematic studies on high iodine groundwater worldwide. To better understand the sources and processes responsible for iodine enrichment in the groundwater of the Datong Basin, the hydrochemical characteristics of groundwater and geochemical features of aquifer sediments were studied. High iodine groundwater mainly occurs in the center of the Datong Basin with iodine concentrations ranging between 3.31 and 1890 μg L(-1). Most samples with iodine concentrations higher than 500 μg L(-1) are from wells with depths between 75 and 120 m. High pH and a reducing environment are favorable for iodine enrichment in the groundwater, with iodide as the dominant species that accounts for 63.2-99.3% of the total iodine. Sediment samples from a borehole specifically drilled for this study contain 0.18-1.46 mg kg(-1) iodine that is moderately correlated with total organic carbon (TOC). The results of sequential extraction experiments show that iodine is mostly bound to iron oxyhydroxides and organic matter in the sediments. The mobilization processes of iodine are proposed to include reductive dissolution of iron oxyhydroxides and transformations among iodide, iodate and organic iodine driven by microbial activities under alkaline and reducing conditions.
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Affiliation(s)
- Junxia Li
- School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 430074 Wuhan, China
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