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102
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Shaikh N, Taujale S, Zhang H, Artyushkova K, Ali AMS, Cerrato JM. Spectroscopic Investigation of Interfacial Interaction of Manganese Oxide with Triclosan, Aniline, and Phenol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10978-10987. [PMID: 27668521 DOI: 10.1021/acs.est.6b02673] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigated the reaction of manganese oxide [MnOx(s)] with phenol, aniline, and triclosan in batch experiments using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and aqueous chemistry measurements. Analyses of XPS high-resolution spectra suggest that the Mn(III) content increased 8-10% and the content of Mn(II) increased 12-15% in the surface of reacted MnOx(s) compared to the control, indicating that the oxidation of organic compounds causes the reduction of MnOx(s). Fitting of C 1s XPS spectra suggests an increase in the number of aromatic and aliphatic bonds for MnOx(s) reacted with organic compounds. The presence of 2.7% Cl in the MnOx(s) surface after reaction with triclosan was detected by XPS survey scans, while no Cl was detected in MnOx-phenol, MnOx-aniline, and MnOx-control. Raman spectra confirm the increased intensity of carbon features in MnOx(s) samples that reacted with organic compounds compared to unreacted MnOx(s). These spectroscopy results indicate that phenol, aniline, triclosan, and related byproducts are associated with the surface of MnOx(s)-reacted samples. The results from this research contribute to a better understanding of interactions between MnOx(s) and organic compounds that are relevant to natural and engineered environments.
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Affiliation(s)
- Nabil Shaikh
- Department of Civil Engineering, University of New Mexico , MSC01 1070, Albuquerque, New Mexico 87131, United States
| | - Saru Taujale
- Department of Civil and Environmental Engineering, Temple University , 1947 North 12th Street, Philadelphia, Pennsylvania 19122, United States
| | - Huichun Zhang
- Department of Civil and Environmental Engineering, Temple University , 1947 North 12th Street, Philadelphia, Pennsylvania 19122, United States
| | - Kateryna Artyushkova
- Department of Chemical Engineering, University of New Mexico , MSC01 1120, Albuquerque, New Mexico 87131, United States
| | - Abdul-Mehdi S Ali
- Department of Earth and Planetary Sciences, University of New Mexico , MSC03 2040, Albuquerque, New Mexico 87131, United States
| | - José M Cerrato
- Department of Civil Engineering, University of New Mexico , MSC01 1070, Albuquerque, New Mexico 87131, United States
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103
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Chen J, Chen X, Xu Z, Xu WJ, Li JJ, Jia HP, Chen J. Syntheses of Hierarchical MnO2viaH2O2Selectively Reducing KMnO4for Catalytic Combustion of Toluene. ChemistrySelect 2016. [DOI: 10.1002/slct.201600921] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jin Chen
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Xi Chen
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Zhen Xu
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Wen-Jian Xu
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Juan-Juan Li
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Hong-Peng Jia
- Center for Excellence in Urban Atmospheric Environment; and Key Laboratory of Urban Pollutant Conversion; Institute of Urban Environment; Chinese Academy of Sciences; Xiamen 361021 China
| | - Jing Chen
- State Key Laboratory of Structural Chemistry; Fujian Institute of Research on the Structure of Matter; Chinese Academy of Sciences; Fuzhou 350002 China
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104
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Mahdi Najafpour M, Jafarian Sedigh D, Maedeh Hosseini S, Zaharieva I. Treated Nanolayered Mn Oxide by Oxidizable Compounds: A Strategy To Improve the Catalytic Activity toward Water Oxidation. Inorg Chem 2016; 55:8827-32. [DOI: 10.1021/acs.inorgchem.6b01334] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohammad Mahdi Najafpour
- Department of Chemistry, and Center of
Climate Change and Global Warming, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Davood Jafarian Sedigh
- Department of Chemistry, and Center of
Climate Change and Global Warming, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Seyedeh Maedeh Hosseini
- Department of Chemistry, and Center of
Climate Change and Global Warming, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Ivelina Zaharieva
- Freie Universität Berlin, Fachbereich Physik, Arnimallee
14, D-14195 Berlin, Germany
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105
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Im J, Löffler FE. Fate of Bisphenol A in Terrestrial and Aquatic Environments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8403-16. [PMID: 27401879 DOI: 10.1021/acs.est.6b00877] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Bisphenol A (2,2-bis[4-hydroxyphenyl]propane, BPA), the monomer used to produce polycarbonate plastic and epoxy resins, is weakly estrogenic and therefore of environmental and human health interest. Due to the high production volumes and disposal of products made from BPA, polycarbonate plastic and epoxy resins, BPA has entered terrestrial and aquatic environments. In the presence of oxygen, diverse taxa of bacteria, fungi, algae and even higher plants metabolize BPA, but anaerobic microbial degradation has not been documented. Recent reports demonstrated that abiotic processes mediate BPA transformation and mineralization in the absence of oxygen, indicating that BPA is susceptible to degradation under anoxic conditions. This review summarizes biological and nonbiological processes that lead to BPA transformation and degradation, and identifies research needs to advance predictive understanding of the longevity of BPA and its transformation products in environmental systems.
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Affiliation(s)
- Jeongdae Im
- Department of Microbiology, University of Massachusetts , Amherst, Massachusetts 01002, United States
| | - Frank E Löffler
- Center for Environmental Biotechnology, University of Tennessee , Knoxville, Tennessee 37996, United States
- Department of Microbiology, University of Tennessee , Knoxville, Tennessee 37996, United States
- Department of Civil and Environmental Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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106
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Tong F, Gu X, Gu C, Xie J, Xie X, Jiang B, Wang Y, Ertunc T, Schäffer A, Ji R. Stimulation of Tetrabromobisphenol A Binding to Soil Humic Substances by Birnessite and the Chemical Structure of the Bound Residues. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6257-6266. [PMID: 27223831 DOI: 10.1021/acs.est.5b06265] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Studies have shown the main fate of the flame retardant tetrabromobisphenol A (TBBPA) in soils is the formation of bound residues, and mechanisms on it are less-understood. This study investigated the effect of birnessite (δ-MnO2), a naturally occurring oxidant in soils, on the formation of bound residues. (14)C-labeled TBBPA was used to investigate the pH dependency of TBBPA bound-residue formation to two soil humic acids (HAs), Elliott soil HA and Steinkreuz soil HA, in the presence of δ-MnO2. The binding of TBBPA and its transformation products to both HAs was markedly increased (3- to 17-fold) at all pH values in the presence of δ-MnO2. More bound residues were formed with the more aromatic Elliott soil HA than with Steinkreuz soil HA. Gel-permeation chromatography revealed a uniform distribution of the bound residues within Steinkreuz soil HA and a nonuniform distribution within Elliott soil HA. (13)C NMR spectroscopy of (13)C-TBBPA residues bound to (13)C-depleted HA suggested that in the presence of δ-MnO2, binding occurred via ester and ether and other types of covalent bonds besides HA sequestration. The insights gained in this study contribute to an understanding of the formation of TBBPA bound residues facilitated by δ-MnO2.
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Affiliation(s)
| | | | | | | | | | | | | | - Tanya Ertunc
- Institute for Environmental Research, RWTH Aachen University , D-52056 Aachen, Germany
| | - Andreas Schäffer
- Institute for Environmental Research, RWTH Aachen University , D-52056 Aachen, Germany
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107
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Salter-Blanc AJ, Bylaska EJ, Lyon MA, Ness SC, Tratnyek PG. Structure-Activity Relationships for Rates of Aromatic Amine Oxidation by Manganese Dioxide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:5094-5102. [PMID: 27074054 DOI: 10.1021/acs.est.6b00924] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
New energetic compounds are designed to minimize their potential environmental impacts, which includes their transformation and the fate and effects of their transformation products. The nitro groups of energetic compounds are readily reduced to amines, and the resulting aromatic amines are subject to oxidation and coupling reactions. Manganese dioxide (MnO2) is a common environmental oxidant and model system for kinetic studies of aromatic amine oxidation. In this study, a training set of new and previously reported kinetic data for the oxidation of model and energetic-derived aromatic amines was assembled and subjected to correlation analysis against descriptor variables that ranged from general purpose [Hammett σ constants (σ(-)), pKas of the amines, and energies of the highest occupied molecular orbital (EHOMO)] to specific for the likely rate-limiting step [one-electron oxidation potentials (Eox)]. The selection of calculated descriptors (pKa, EHOMO, and Eox) was based on validation with experimental data. All of the correlations gave satisfactory quantitative structure-activity relationships (QSARs), but they improved with the specificity of the descriptor. The scope of correlation analysis was extended beyond MnO2 to include literature data on aromatic amine oxidation by other environmentally relevant oxidants (ozone, chlorine dioxide, and phosphate and carbonate radicals) by correlating relative rate constants (normalized to 4-chloroaniline) to EHOMO (calculated with a modest level of theory).
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Affiliation(s)
- Alexandra J Salter-Blanc
- Institute of Environmental Health, Oregon Health & Science University , 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Eric J Bylaska
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - Molly A Lyon
- Institute of Environmental Health, Oregon Health & Science University , 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Stuart C Ness
- Institute of Environmental Health, Oregon Health & Science University , 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Paul G Tratnyek
- Institute of Environmental Health, Oregon Health & Science University , 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
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108
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Wang Z, Zhu W, Qiu Y, Yi X, von dem Bussche A, Kane A, Gao H, Koski K, Hurt R. Biological and environmental interactions of emerging two-dimensional nanomaterials. Chem Soc Rev 2016; 45:1750-80. [PMID: 26923057 PMCID: PMC4820079 DOI: 10.1039/c5cs00914f] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Two-dimensional materials have become a major focus in materials chemistry research worldwide with substantial efforts centered on synthesis, property characterization, and technological application. These high-aspect ratio sheet-like solids come in a wide array of chemical compositions, crystal phases, and physical forms, and are anticipated to enable a host of future technologies in areas that include electronics, sensors, coatings, barriers, energy storage and conversion, and biomedicine. A parallel effort has begun to understand the biological and environmental interactions of synthetic nanosheets, both to enable the biomedical developments and to ensure human health and safety for all application fields. This review covers the most recent literature on the biological responses to 2D materials and also draws from older literature on natural lamellar minerals to provide additional insight into the essential chemical behaviors. The article proposes a framework for more systematic investigation of biological behavior in the future, rooted in fundamental materials chemistry and physics. That framework considers three fundamental interaction modes: (i) chemical interactions and phase transformations, (ii) electronic and surface redox interactions, and (iii) physical and mechanical interactions that are unique to near-atomically-thin, high-aspect-ratio solids. Two-dimensional materials are shown to exhibit a wide range of behaviors, which reflect the diversity in their chemical compositions, and many are expected to undergo reactive dissolution processes that will be key to understanding their behaviors and interpreting biological response data. The review concludes with a series of recommendations for high-priority research subtopics at the "bio-nanosheet" interface that we hope will enable safe and successful development of technologies related to two-dimensional nanomaterials.
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Affiliation(s)
| | | | | | - Xin Yi
- School of Engineering, USA.
| | | | - Agnes Kane
- Department of Pathology and Laboratory Medicine, USA. and Institute for Molecular and Nanoscale Innovation, USA
| | | | - Kristie Koski
- Department of Chemistry, Brown University, Providence, RI 02912, USA.
| | - Robert Hurt
- School of Engineering, USA. and Institute for Molecular and Nanoscale Innovation, USA
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109
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Li H, Joshi SR, Jaisi DP. Degradation and Isotope Source Tracking of Glyphosate and Aminomethylphosphonic Acid. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:529-38. [PMID: 26689867 DOI: 10.1021/acs.jafc.5b04838] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Glyphosate [N-(phosphonomethyl) glycine], an active ingredient of the herbicide Roundup, and its main metabolite, aminomethylphosphonic acid (AMPA), have been frequently reported to be present in soils and other environments and thus have heightened public concerns on their potential adverse effects. Understanding the fate of these compounds and differentiating them from other naturally occurring compounds require a toolbox of methods that can go beyond conventional methods. Here, we applied individual isotope labeling technique whereby each compound or mineral involved in the glyphosate and AMPA degradation reaction was either synthesized or chosen to have distinct (18)O/(16)O ratios so that the source of incorporated oxygen in the orthophosphate generated and corresponding isotope effect during C-P bond cleavage could be identified. Furthermore, we measured original isotope signatures of a few commercial glyphosate sources to identify their source-specific isotope signatures. Our degradation kinetics results showed that the rate of glyphosate degradation was higher than that of AMPA in all experimental conditions, and both the rate and extent of degradation were lowest under anoxic conditions. Oxygen isotope ratios (δ(18)OP) of orthophosphate generated from glyphosate and AMPA degradation suggested that one external oxygen atom from ambient water, not from dissolved oxygen or mineral, was incorporated into orthophosphate with the other three oxygen atoms inherited from the parent molecule. Interestingly, δ(18)OP values of all commercial glyphosate products studied were found to be the lightest among all orthophosphates known so far. Furthermore, isotope composition was found to be unaffected due to variable degradation kinetics, light/dark, and oxic/anoxic conditions. These results highlight the importance of phosphate oxygen isotope ratios as a nonconventional tool to potentially distinguish glyphosate sources and products from other organophosphorus compounds and orthophosphate in the environment.
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Affiliation(s)
- Hui Li
- Department of Plant and Soil Sciences, University of Delaware , Newark, Delaware 19716, United States
| | - Sunendra R Joshi
- Department of Plant and Soil Sciences, University of Delaware , Newark, Delaware 19716, United States
| | - Deb P Jaisi
- Department of Plant and Soil Sciences, University of Delaware , Newark, Delaware 19716, United States
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110
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Grebel JE, Charbonnet JA, Sedlak DL. Oxidation of organic contaminants by manganese oxide geomedia for passive urban stormwater treatment systems. WATER RESEARCH 2016; 88:481-491. [PMID: 26521218 DOI: 10.1016/j.watres.2015.10.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/10/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
To advance cost-effective strategies for removing trace organic contaminants from urban runoff, the feasibility of using manganese oxides as a geomedia amendment in engineered stormwater infiltration systems to oxidize organic contaminants was evaluated. Ten representative organic chemicals that have previously been detected in urban stormwater were evaluated for reactivity in batch experiments with birnessite. With respect to reactivity, contaminants could be classified as: highly reactive (e.g., bisphenol A), moderately reactive (e.g., diuron) and unreactive (e.g., tris(2-chloro-1-propyl)phosphate). Bisphenol A and diuron reacted with birnessite to produce a suite of products, including ring-cleavage products for bisphenol A and partially dechlorinated products for diuron. Columns packed with manganese oxide-coated sand were used evaluate design parameters for an engineered infiltration system, including necessary contact times for effective treatment, as well as the impacts of stormwater matrix variables, such as solution pH, concentration of natural organic matter and major anions and cations. The manganese oxide geomedia exhibited decreased reactivity when organic contaminants were oxidized, especially in the presence of divalent cations, bicarbonate, and natural organic matter. Under typical conditions, the manganese oxides are expected to retain their reactivity for 25 years.
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Affiliation(s)
- Janel E Grebel
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt), Department of Civil & Environmental Engineering, University of California, Berkeley, CA, USA
| | - Joseph A Charbonnet
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt), Department of Civil & Environmental Engineering, University of California, Berkeley, CA, USA
| | - David L Sedlak
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt), Department of Civil & Environmental Engineering, University of California, Berkeley, CA, USA.
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111
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Ratti M, Canonica S, McNeill K, Bolotin J, Hofstetter TB. Isotope Fractionation Associated with the Indirect Photolysis of Substituted Anilines in Aqueous Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12766-12773. [PMID: 26418612 DOI: 10.1021/acs.est.5b03119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Organic micropollutants containing aniline substructures are susceptible to different light-induced transformation processes in aquatic environments and water treatment operations. Here, we investigated the magnitude and variability of C and N isotope fractionation during the indirect phototransformation of four para-substituted anilines in aerated aqueous solutions. The model photosensitizers, namely 9,10-anthraquinone-1,5-disulfonate and methylene blue, were used as surrogates for dissolved organic matter chromophores generating excited triplet states in sunlit surface waters. The transformation of aniline, 4-CH3-, 4-OCH3-, and 4-Cl-aniline by excited triplet states of the photosensitizers was associated with inverse and normal N isotope fractionation, whereas C isotope fractionation was negligible. The apparent 15N kinetic isotope effects (AKIE) were almost identical for both photosensitizers, increased from 0.9958±0.0013 for 4-OCH3-aniline to 1.0035±0.0006 for 4-Cl-aniline, and correlated well with the electron donating properties of the substituent. N isotope fractionation is pH-dependent in that H+ exchange reactions dominate below and N atom oxidation processes above the pKa value of the substituted aniline's conjugate acid. Correlations of C and N isotope fractionation for indirect phototransformation were different from those determined previously for the direct photolysis of chloroanilines and offer new opportunities to distinguish between abiotic degradation pathways.
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Affiliation(s)
- Marco Ratti
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
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112
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Simanova AA, Peña J. Time-Resolved Investigation of Cobalt Oxidation by Mn(III)-Rich δ-MnO2 Using Quick X-ray Absorption Spectroscopy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:10867-76. [PMID: 26236964 DOI: 10.1021/acs.est.5b01088] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Manganese oxides are important environmental oxidants that control the fate of many organic and inorganic species including cobalt. We applied ex situ quick X-ray absorption spectroscopy (QXAS) to determine the time evolution of Co(II) and Co(III) surface loadings and their respective average surface speciation in Mn(III)-rich δ-MnO2 samples at pH 6.5 and loadings of 0.01-0.20 mol Co mol(-1) Mn. In this Mn oxide, which contained few unoccupied vacancies but abundant Mn(III) at edge and interlayer sites, Co(II) sorption and oxidation started at the particle edges. We found no evidence for Co(II) oxidation by interlayer Mn(III) or Mn(III, IV) adjacent to vacancy sites at <10 min. After 10 min, basal surface sites were implicated due to slow Co oxidation by interlayer Mn(III) and reactive sites formed upon removal of interlayer Mn(III), such that 50-60% of the sorbed Co was incorporated into the MnO2 sheets or adsorbed at vacancy sites by 12 h. Our findings indicate that the redox reactivity of surface sites depends on Mn valence and crystallographic location, with Mn(III) at the edges being the most effective oxidant at short reaction times and Mn(III,IV) in the MnO2 sheet contributing at longer reaction times.
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Affiliation(s)
- Anna A Simanova
- Institute of Earth Surface Dynamics, University of Lausanne , CH-1015 Lausanne, Switzerland
| | - Jasquelin Peña
- Institute of Earth Surface Dynamics, University of Lausanne , CH-1015 Lausanne, Switzerland
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113
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Ding J, Su M, Wu C, Lin K. Transformation of triclosan to 2,8-dichlorodibenzo-p-dioxin by iron and manganese oxides under near dry conditions. CHEMOSPHERE 2015; 133:41-46. [PMID: 25880455 DOI: 10.1016/j.chemosphere.2015.03.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 03/25/2015] [Accepted: 03/27/2015] [Indexed: 06/04/2023]
Abstract
Triclosan (TCS) is a broad-spectrum antibacterial agent widely used in household and personal care products and is frequently detected in the environment. Previous studies have shown that TCS could be converted to the more toxic compound 2,8-dichlorodibenzo-p-dioxins (2,8-DCDD) in photochemical reactions and incineration processes. In this study, we demonstrated the formation of 2,8-DCDD from the oxidation of TCS by α-FeOOH and a natural manganese oxides (MnOx) sand. Experiments at room temperature and under near dry conditions showed that Fe and Mn oxides readily catalyzed the conversion of TCS to 2,8-DCDD and other products. Approximately 5.5% of TCS was transformed to 2,8-DCDD by α-FeOOH in 45 d and a higher conversion percentage (6.7%) was observed for MnOx sand in 16d. However, the presence of water in the samples significantly inhibited the formation of 2,8-DCDD. Besides 2,8-DCDD, 2,4-dichlorphenol (2,4-DCP), 4-chlorobenzene-1,2-diol, 2-chloro-5-(2,4-dichlorophenoxy)benzene-1,4-diol, and 2-chloro-5-(2,4-dichlorophenoxy)-1,4-benzoquinone were identified in the reactions. The possible pathways for the formation of reaction products were proposed. This study suggests that Fe and Mn oxides-mediated transformation of TCS under near dry conditions might be another potential pathway for the formation of 2,8-DCDD in the natural environment.
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Affiliation(s)
- Jiafeng Ding
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Mian Su
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Cuiwei Wu
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Kunde Lin
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China; College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
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114
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