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Bai X, Yang Q, Guo Y, Hao B, Zhang R, Duan R, Li J. Alkyl halide formation from degradation of carboxylic acids in the presence of Fe(III) and halides under light irradiation. WATER RESEARCH 2023; 235:119842. [PMID: 36921357 DOI: 10.1016/j.watres.2023.119842] [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: 12/01/2022] [Revised: 02/23/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
Advanced oxidation processes (AOPs) have been widely used in water and wastewater treatment and have shown excellent performance in remediating contaminated water. However, their oxidation byproducts, including halogenated organics, have recently attracted increasing attention. Alkyl halides are among the most important environmental pollutants in nature. Here, we report a Fenton-like reaction in which alkyl halides can form during the photodegradation of aliphatic carboxylic acids in the presence of Fe(III) and halides. Chloromethane, chloroethane, and 1-chloropropane were produced from the degradation of acetic acid, propionic acid and n-butyric acid, respectively. CH3Cl, CH2Cl2 and CHCl3 were all identified as the products of acetic acid with the yields of approximately 5.1%, 0.2% and 0.005%, respectively. It was demonstrated that hydroxyl radicals, halogen radicals and alkyl radicals were involved in the formation of alkyl halides. A possible mechanism of chloromethane formation was proposed based on the results. In real samples of saline water, the addition of carboxylic acid and Fe(III) significantly promoted the generation of CH3Cl under xenon lamp irradiation. The results indicated that the coexistence of Fe(III), halides and carboxylic acids enhanced the photochemical release of alkyl halides. The reactions described in this paper may contribute to knowledge on the mechanism of halogenated byproduct formation during AOPs.
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Affiliation(s)
- Xueling Bai
- Department of Chemistry, China Agricultural University, Beijing, 100193 China
| | - Qian Yang
- Department of Chemistry, China Agricultural University, Beijing, 100193 China
| | - Yang Guo
- Department of Chemistry, China Agricultural University, Beijing, 100193 China
| | - Baoqiang Hao
- Department of Chemistry, China Agricultural University, Beijing, 100193 China
| | - Renyuan Zhang
- Department of Chemistry, China Agricultural University, Beijing, 100193 China
| | - Ran Duan
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Li
- Department of Chemistry, China Agricultural University, Beijing, 100193 China.
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2
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Yuan X, Zhang D, Liang C, Zhang X. Spontaneous Reduction of Transition Metal Ions by One Electron in Water Microdroplets and the Atmospheric Implications. J Am Chem Soc 2023; 145:2800-2805. [PMID: 36705987 DOI: 10.1021/jacs.3c00037] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Freshman chemistry teaches that Fe3+ and Cu2+ ions are stable in water solutions, but their reduced forms, Fe2+ and Cu+, cannot exist in water as the major oxidation state due to the fast oxidation by O2 and/or disproportionation. Contrary to these well-known facts, significant fractions of dissolved Fe and Cu species exist in their reduced oxidation states in atmospheric water such as deliquesced aerosols, clouds, and fog droplets. Current knowledge attributes these phenomena to the stabilization of the lower oxidation states by the complexation of ligands and the various photochemical or thermal pathways that can reduce the higher oxidation states. In this study, by spraying the water solutions of transition metal ions into microdroplets, we show the results of the spontaneous reduction of ligated Fe(III) and Cu(II) species into Fe(II) and Cu(I) species, presenting a previously unknown source of reduced transition metal ions in atmospheric water. It is the spontaneously generated electrons in water microdroplets that are responsible for the reduction. Control experiments in the atmosphere and in a glove box filled with precisely controlled gaseous contents reveal that O2, CO2, and NO2 are the major competitors for the electrons, forming O2-, HCO2-, and NO2-, respectively. Taking these findings together, we opine that microdroplet chemistry might play significant but previously underestimated roles in atmospheric redox chemistry.
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Affiliation(s)
- Xu Yuan
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Dongmei Zhang
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Chiyu Liang
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China
| | - Xinxing Zhang
- College of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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Wu Y, Qiu T, Wang Y, Liu H, Sun W, Dong W, Mailhot G. Application of a microbial siderophore desferrioxamine B in sunlight/Fe 3+/persulfate system: from the radical formation to the degradation of atenolol at neutral pH. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:36782-36788. [PMID: 32572744 DOI: 10.1007/s11356-020-09692-2] [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: 02/22/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
The present work reported a modified persulfate activation process with a microbial siderophore named desferrioxamine B (DFOB). DFOB was a natural complexing agent and could complex with Fe3+ strongly. The photochemical reactivity of Fe(III)-DFOB was studied. Fe2+ and HO• were produced from Fe(III)-DFOB photolysis. Furthermore, the degradation of atenolol (ATL) was followed in light/persulfate (PS)/Fe(III)-DFOB system. The main oxidative radicals were SO4•- in this system. The results of pH effect showed that there was no obviously fluctuation on ATL degradation efficiency with the pH increased from 2.5 to 8.4. Moreover, kSO4•-,DFOB was determined by laser flash photolysis (LFP) experiments. DFOB had positive effect on Fe2+ formation but negative effect on ATL degradation due to the high react rate constant between DFOB and SO4•-. The effects of chloride and carbonate ion were also investigated. The results in this study proposed the reaction mechanism of the modified persulfate activation process, and it could be applied in neutral and weak-alkaline pH range.
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Affiliation(s)
- Yanlin Wu
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
- Institut de Chimie de Clermont-Ferrand, SIGMA Clermont, Université Clermont Auvergne, CNRS, F-63000, Clermont-Ferrand, France.
| | - Tian Qiu
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China
| | - Yu Wang
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China
| | - Huihui Liu
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China
| | - Weiqiang Sun
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China
| | - Wenbo Dong
- Department of Environmental Science & Engineering, Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai, 200433, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Gilles Mailhot
- Institut de Chimie de Clermont-Ferrand, SIGMA Clermont, Université Clermont Auvergne, CNRS, F-63000, Clermont-Ferrand, France
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4
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Xu X, Chen J, Zhu C, Li J, Sui X, Liu L, Sun J. Fog composition along the Yangtze River basin: Detecting emission sources of pollutants in fog water. J Environ Sci (China) 2018; 71:2-12. [PMID: 30195679 DOI: 10.1016/j.jes.2017.09.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 09/15/2017] [Accepted: 09/18/2017] [Indexed: 06/08/2023]
Abstract
To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Wuhan during November 2015. Fifteen fog water samples were collected by using a three-stage Caltech Active Strand Cloud water Collector (CASCC). The three-stage CASCC was mounted on the board of a ship. PH, electrical conductivity (EC), H2O2, HCHO, S(IV), ten inorganic ions, seven organicacids and sixteen trace metal elements were measured in this study. The pH of fog water samples ranged from weakly acidic (pH4.3) to weakly alkaline (pH7.05) and the EC ranged from 32.4 to 436.3μS/cm. The main cations in fog water were NH4+ and Ca2+, accounting for 12.35% and 29.07% of those inorganic ions, respectively. In addition, SO42- and NO3- contributed to 25.52% and 12.93% to total anion concentrations respectively. Moreover, the dominant kinds of organicacids were formate and oxalate, occupying 45.28% and 28.03% of the total organicacids, respectively. For trace metal elements in fog samples, Al, Fe, Zn, and Ba revealed 34.6%, 16.4%, 19.3%, and 20.9% contributions to these sixteen trace element concentrations, respectively. The results indicated that pollutants were mainly from human activities, including fossil fuel combustion, biomass burning, steel-making, stone quarrying and sand digging. Besides, natural sources including natural background levels and long-range transport of sea salt particles also aggravated the pollution levels in the fog events along the Yangtze River.
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Affiliation(s)
- Xianmang Xu
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China
| | - Jianmin Chen
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China.
| | - Chao Zhu
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China
| | - Jiarong Li
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China
| | - Xiao Sui
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China
| | - Lu Liu
- School of Environmental Science and Engineering, Environment Research Institute, Shandong University, Jinan 250100, China
| | - Jianfeng Sun
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
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Singh DK, Gupta T. Role of ammonium ion and transition metals in the formation of secondary organic aerosol and metallo-organic complex within fog processed ambient deliquescent submicron particles collected in central part of Indo-Gangetic Plain. CHEMOSPHERE 2017; 181:725-737. [PMID: 28478233 DOI: 10.1016/j.chemosphere.2017.04.080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 04/15/2017] [Accepted: 04/18/2017] [Indexed: 06/07/2023]
Abstract
In this study we observed the role of ammonium ion (NH4+) and transition metals (Fe, Mn, Cr, and Cu) present in ambient submicron particles in stabilizing and enhancing the yield of water soluble organic carbon (WSOC). A good correlation of WSOC with transition metals and NH4+ was found (R2 = 0.87 and 0.71), respectively within foggy episode collected ambient PM1 (particles having aerodynamic diameter ≤1.0 μm) suggesting plausibleness of alternate oxidation (primarily various carbonyls into their respective organic acids, esters and other derivatives.) and aging mechanisms. Molar concentration of ammonium ion was observed to be exceeded over and above to require in neutralizing the sulphate and nitrate which further hints its role in the neutralization, stabilization and enhancement of subset of WSOC such as water soluble organic acids. Transition metals were further apportioned using enrichment factor analysis. The source of Fe, Mn, and Cr was found to be crustal and Cu was tagged to anthropogenic origin. This study also described the plausible role of significant predictors (Fe and Cu) in the secondary organic aerosol (SOA) formation through effect of Fenton chemistry. Mass-to-charge ratio of identified oxalic acid from our published recent field study (carried out from same sampling location) was used for understanding the possible metallo-organic complex with Fe supports the substantial role of Fe in SOA formation in the deliquescent submicron particles facilitated by aqueous-phase chemistry.
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Affiliation(s)
- Dharmendra Kumar Singh
- Chubu Institute for Advanced Studies, Chubu University, Kasugai-shi, Aichi, 487-8501, Japan.
| | - Tarun Gupta
- Department of Civil Engineering, Center for Environmental Science and Engineering, Indian Institute of Technology Kanpur, 208016, India.
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6
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Chu B, Liggio J, Liu Y, He H, Takekawa H, Li SM, Hao J. Influence of metal-mediated aerosol-phase oxidation on secondary organic aerosol formation from the ozonolysis and OH-oxidation of α-pinene. Sci Rep 2017; 7:40311. [PMID: 28059151 PMCID: PMC5216392 DOI: 10.1038/srep40311] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/02/2016] [Indexed: 12/12/2022] Open
Abstract
The organic component is the most abundant fraction of atmospheric submicron particles, while the formation mechanisms of secondary organic aerosol (SOA) are not fully understood. The effects of sulfate seed aerosols on SOA formation were investigated with a series of experiments carried out using a 9 m3 smog chamber. The presence of FeSO4 or Fe2(SO4)3 seed aerosols decreased SOA yields and increased oxidation levels in both ozonolysis and OH-oxidation of α-pinene compared to that in the presence of ZnSO4 or (NH4)2SO4. These findings were explained by metal-mediated aerosol-phase oxidation of organics: reactive radicals were generated on FeSO4 or Fe2(SO4)3 seed aerosols and reacted further with the organic mass. This effect would help to explain the high O/C ratios of organics in ambient particles that thus far cannot be reproduced in laboratory and model studies. In addition, the gap in the SOA yields between experiments with different seed aerosols was more significant in OH-oxidation experiments compared to ozonolysis experiments, while the gap in estimated O/C ratios was less obvious. This may have resulted from the different chemical compositions and oxidation levels of the SOA generated in the two systems, which affect the branching ratio of functionalization and fragmentation during aerosol oxidation.
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Affiliation(s)
- Biwu Chu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.,Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - John Liggio
- Air Quality Research Division, Environment Canada, Toronto, Ontario M3H5T4, Canada
| | - Yongchun Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.,Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.,Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hideto Takekawa
- Toyota Central Research and Development Laboratory, Nagakute, Aichi 480-1192, Japan
| | - Shao-Meng Li
- Air Quality Research Division, Environment Canada, Toronto, Ontario M3H5T4, Canada
| | - Jiming Hao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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7
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Wu L, Liu Q, Tong S, Jing B, Wang W, Guo Y, Ge M. Mechanism and Kinetics of Heterogeneous Reactions of Unsaturated Organic Acids on α-Al 2 O 3 and CaCO 3. Chemphyschem 2016; 17:3515-3523. [PMID: 27504908 DOI: 10.1002/cphc.201600668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Indexed: 11/05/2022]
Abstract
Heterogeneous reactions have a vital role in the atmosphere due to their significant effects on the evolution of atmospheric aerosols, which in turn contribute to air pollution. However, the mechanism and kinetics of these processes involving unsaturated organic acids, important types of volatile organic compounds, are still unclear. In this work, the heterogeneous uptake of two representative atmospheric unsaturated organic acids (acrylic acid and methacrylic acid) on mineral aerosols including α-Al2 O3 and CaCO3 are investigated using a Knudsen cell reactor and an in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) reactor. The corresponding reaction pathways are proposed from the DRIFTS analysis. In addition, the initial uptake coefficients of unsaturated organic acids and their heterogeneous fate are obtained for the first time. Our results suggest that heterogeneous reactions on α-Al2 O3 and CaCO3 can be important sinks for acrylic acid and methacrylic acid, as well as possible contributors to the organic coating found on atmospheric aerosols, especially in high-pollution events.
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Affiliation(s)
- Lingyan Wu
- State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing, 100081, P.R. China
| | - Qifan Liu
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P.R.China
| | - Shengrui Tong
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Bo Jing
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Weigang Wang
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yucong Guo
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Maofa Ge
- Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P.R.China.,CAS Center for Excellence in Urban Atmospheric Environment (CEUAE), Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, P. R. China
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Pöschl U, Shiraiwa M. Multiphase chemistry at the atmosphere-biosphere interface influencing climate and public health in the anthropocene. Chem Rev 2015; 115:4440-75. [PMID: 25856774 DOI: 10.1021/cr500487s] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ulrich Pöschl
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Manabu Shiraiwa
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
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Marris H, Deboudt K, Flament P, Grobéty B, Gieré R. Fe and Mn oxidation states by TEM-EELS in fine-particle emissions from a Fe-Mn alloy making plant. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:10832-10840. [PMID: 24000787 DOI: 10.1021/es400368s] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fine particles were sampled both inside the chimneys and in the near-field of an Fe-Mn-alloy manufacturing plant. The transfer from one point to another point in the environment, as well as the bioavailability and toxicity of these two metals, depend above all on their speciation. The oxidation states of iron and manganese in the collected particles were determined by using transmission electron microscopy coupled with electron energy-loss spectroscopy (TEM-EELS). The mineralogical identity of these metal-rich particles was determined by selected area electron diffraction (SAED) coupled with energy-dispersive X-ray spectroscopy (EDX). This study shows that both iron and manganese in metallic particles are prone to oxidation reactions via gas/particle conversion mechanisms, which take place in the flue gases within the smoke stacks. This phenomenon is more pronounced for the smallest Fe-rich particles. However, no further change of oxidation state of the two elements was observed in the near-field of the plant, after emission into the atmosphere (within <2000 m of the smoke stacks). The oxidation states of iron and manganese remain mainly between +II and +III, which is probably due to short residence time of these particles in the pollution plume.
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Affiliation(s)
- Hélène Marris
- Université du Littoral Côte d'Opale , Laboratoire de Physico-Chimie de l'Atmosphère (LPCA), Bâtiment MREI2, 189A avenue Maurice Schumann, 59140 Dunkerque, France
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Sorooshian A, Wang Z, Coggon MM, Jonsson HH, Ervens B. Observations of sharp oxalate reductions in stratocumulus clouds at variable altitudes: organic acid and metal measurements during the 2011 E-PEACE campaign. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:7747-56. [PMID: 23786214 DOI: 10.1021/es4012383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This work examines organic acid and metal concentrations in northeastern Pacific Ocean stratocumulus cloudwater samples collected by the CIRPAS Twin Otter between July and August 2011. Correlations between a suite of various monocarboxylic and dicarboxylic acid concentrations are consistent with documented aqueous-phase mechanistic relationships leading up to oxalate production. Monocarboxylic and dicarboxylic acids exhibited contrasting spatial profiles reflecting their different sources; the former were higher in concentration near the continent due to fresh organic emissions. Concentrations of sea salt crustal tracer species, oxalate, and malonate were positively correlated with low-level wind speed suggesting that an important route for oxalate and malonate entry in cloudwater is via some combination of association with coarse particles and gaseous precursors emitted from the ocean surface. Three case flights show that oxalate (and no other organic acid) concentrations drop by nearly an order of magnitude relative to samples in the same vicinity. A consistent feature in these cases was an inverse relationship between oxalate and several metals (Fe, Mn, K, Na, Mg, Ca), especially Fe. By means of box model studies we show that the loss of oxalate due to the photolysis of iron oxalato complexes is likely a significant oxalate sink in the study region due to the ubiquity of oxalate precursors, clouds, and metal emissions from ships, the ocean, and continental sources.
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Affiliation(s)
- Armin Sorooshian
- Chemical and Environmental Engineering, University of Arizona , Tucson, Arizona 85721, USA.
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11
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Oakes M, Rastogi N, Majestic BJ, Shafer M, Schauer JJ, Edgerton ES, Weber RJ. Characterization of soluble iron in urban aerosols using near-real time data. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012532] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Rubasinghege G, Lentz RW, Scherer MM, Grassian VH. Simulated atmospheric processing of iron oxyhydroxide minerals at low pH: roles of particle size and acid anion in iron dissolution. Proc Natl Acad Sci U S A 2010; 107:6628-33. [PMID: 20360560 PMCID: PMC2872379 DOI: 10.1073/pnas.0910809107] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A number of recent studies have shown that iron dissolution in Fe-containing dust aerosol can be linked to source material (mineral or anthropogenic), mineralogy, and iron speciation. All of these factors need to be incorporated into atmospheric chemistry models if these models are to accurately predict the impact of Fe-containing dusts into open ocean waters. In this report, we combine dissolution measurements along with spectroscopy and microscopy to focus on nanoscale size effects in the dissolution of Fe-containing minerals in low-pH environments and the importance of acid type, including HNO(3), H(2)SO(4), and HCl, on dissolution. All of these acids are present in the atmosphere, and dust particles have been shown to be associated with nitrate, sulfate, and/or chloride. These measurements are done under light and dark conditions so as to simulate and distinguish between daytime and nighttime atmospheric chemical processing. Both size (nano- versus micron-sized particles) and anion (nitrate, sulfate, and chloride) are found to play significant roles in the dissolution of alpha-FeOOH under both light and dark conditions. The current study highlights these important, yet unconsidered, factors in the atmospheric processing of iron-containing mineral dust aerosol.
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13
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Riemer N, West M, Zaveri RA, Easter RC. Simulating the evolution of soot mixing state with a particle‐resolved aerosol model. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011073] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Borer P, Sulzberger B, Hug SJ, Kraemer SM, Kretzschmar R. Wavelength-dependence of photoreductive dissolution of lepidocrocite (gamma-FeOOH) in the absence and presence of the siderophore DFOB. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:1871-1876. [PMID: 19368185 DOI: 10.1021/es801353t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Photoreductive dissolution of lepidocrocite (gamma-FeOOH) in the presence/absence of the siderophore desferrioxamine B (DFOB) was investigated at different wavelengths. At pH 3 in the absence of DFOB, Fe(II) formation rates normalized to the photon flux increased with decreasing wavelengths below 515 nm, consistent with enhanced Fe(II) formation at lower wavelengths by photolysis of surface Fe(III)-hydroxo groups or by surface scavenging of photoelectrons generated in the semiconducting bulk. In the presence of DFOB at pH 3, photoreductive dissolution rates, normalized to the photon flux, increased more strongly with decreasing wavelengths below 440 nm. We hypothesize that acid-catalyzed hydrolysis of DFOB generates degradation products that form photoreactive surface complexes leading to an increase in photodissolution rates at low pH. At pH 8 in the presence of DFOB, normalized photodissolution rates had a maximum in the spectral window 395-435 nm and were significantly smaller at lower wavelengths, suggesting that adsorbed DFOB is directly involved in the reduction of surface Fe(III) by a light-induced ligand-to-metal charge-transfer reaction within the surface Fe(III)-DFOB complex. The strong response in the visible light suggests that photoreductive dissolution of iron (hydr)oxides promoted by siderophores with hydroxamic acid groups may occur deep into in the euphotic zone of oceans.
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Affiliation(s)
- Paul Borer
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Uberlandstrasse 133, 8600 Dübendorf, Switzerland.
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15
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Alexander B, Park RJ, Jacob DJ, Gong S. Transition metal-catalyzed oxidation of atmospheric sulfur: Global implications for the sulfur budget. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010486] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Wang L, Zhang C, Mestankova H, Wu F, Deng N, Pan G, Bolte M, Mailhot G. Photoinduced degradation of 2,4-dichlorophenol in water: influence of various Fe(iii) carboxylates. Photochem Photobiol Sci 2009; 8:1059-65. [DOI: 10.1039/b902607j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Gaubeur I, Avila-Terra LHS, Masini JC, Suárez-Iha MEV. Spectrophotometric flow injection methods for zinc determination in pharmaceutical and biological samples. ANAL SCI 2008; 23:1227-31. [PMID: 17928672 DOI: 10.2116/analsci.23.1227] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Zinc ions form a yellow complex with di-2-pyridyl ketone salicyloylhydrazone (DPKSH). This complex showed maximum absorption at 376 nm, and it was used to develop spectrophotometric flow injection methods for Zn(II) determination in different samples. Two types of flow systems were proposed. In the first system, a linear analytical curve was obtained in a concentration range from 0.217 to 4.60 mg L(-1) Zn(II), with a detection limit of 48.8 microg L(-1). In the second system, a minicolumn packed with an anion exchanger resin was used to concentrate Zn(II) as a chlorocomplex, and a linear analytical curve within a concentration range from 0.0824 to 2.06 mg L(-1) Zn(II) was obtained, having a detection limit of 13.9 microg L(-1). The developed methods were applied to biological and pharmaceutical samples, and a great compliance was observed by comparing the results with ones obtained by an atomic absorption technique.
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Affiliation(s)
- Ivanise Gaubeur
- Centro de Ciéncias Naturais e Humanas, Universidade Federal do ABC, Rua Catequese, 242, 09090-400, Santo André, São Paulo, Brazil.
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18
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Affiliation(s)
- Dave T. F. Kuo
- a Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street, Toronto, Ontario, Canada
| | - Donald W. Kirk
- a Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street, Toronto, Ontario, Canada
| | - Charles Q. Jia
- a Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street, Toronto, Ontario, Canada
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19
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Herckes P, Leenheer JA, Collett JL. Comprehensive characterization of atmospheric organic matter in Fresno, California fog water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:393-9. [PMID: 17310697 DOI: 10.1021/es0607988] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Fogwater collected during winter in Fresno (CA) was characterized by isolating several distinct fractions and characterizing them by infrared and nuclear magnetic resonance (NMR) spectroscopy. More than 80% of the organic matter in the fogwater was recovered and characterized. The most abundant isolated fractions were those comprised of volatile acids (24% of isolated carbon) and hydrophilic acids plus neutrals (28%). Volatile acids, including formic and acetic acid, have been previously identified as among the most abundant individual species in fogwater. Recovered hydrophobic acids exhibited some properties similar to aquatic fulvic acids. An insoluble particulate organic matter fraction contained a substantial amount of biological material, while hydrophilic and transphilic fractions also contained material suggestive of biotic origin. Together, these fractions illustrate the important contribution biological sources make to organic matter in atmospheric fog droplets. The fogwater also was notable for containing a large amount of organic nitrogen present in a variety of species, including amines, nitrate esters, peptides, and nitroso compounds.
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Affiliation(s)
- Pierre Herckes
- Arizona State University, Department of Chemistry and Biochemistry, Tempe, Arizona 85287-1604, USA
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20
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Okada K, Kuroki Y, Nakama Y, Arakaki T, Tanahara A. Wavelength dependence of Fe(ll) photoformation in the water-soluble fraction of aerosols collected in Okinawa, Japan. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2006; 40:7790-5. [PMID: 17256529 DOI: 10.1021/es061649s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We studied photoformation of Fe(II) in the water-soluble fractions (WSFs) of bulk aerosol particles collected in Okinawa, Japan, using radiation at wavelengths of 313, 334, 366, and 405 nm. Fe(II) photoformation quickly reached a steady state within 5 min of irradiation at all wavelengths. The steady-state Fe(II) concentrations were 85+/-13% (n = 39) of the total dissolved Fe (TDFe) concentrations in the WSF solutions. Apparent quantum yields of Fe(II) photoformation were determined based on total absorbance of the WSF solutions, and the means (+/-1 S.D.) were 0.019 (+/-0.034), 0.021 (+/-0.031), 0.014 (+/-0.023), and 0.010 (+/-0.025) at 313, 334, 366, and 405 nm, respectively. Comparison of the observed rates of Fe(II) photoformation for the WSF solutions and the calculated rates from the known Fe(II)-forming compounds suggested that Fe(oxalate)2- could account for the observed Fe(II) photoformation rates if the Fe(oxalate)2- concentration is sufficiently high (>20% of [Fe(III)]o). Furthermore, our study showed that the calculated wavelength dependence of Fe(ll) photoformation from Fe(oxalate)2- was consistent with that of Fe(II) photoformation observed in the WSF solutions. The results obtained here have implications to daytime Fe(III)/ Fe(II) cycles in the atmospheric water droplet.
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Affiliation(s)
- Kouichirou Okada
- Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru Nishihara-cho, Okinawa 903-0213, Japan
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21
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Ermakov AN, Larin IK, Ugarov AA, Purmal AP. Size effects in the catalysis of atmospheric oxidation of SO2 by iron ions. KINETICS AND CATALYSIS 2006. [DOI: 10.1134/s0023158406060036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Ababneh FA, Scott SL, Al-Reasi HA, Lean DRS. Photochemical reduction and reoxidation of aqueous mercuric chloride in the presence of ferrioxalate and air. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 367:831-9. [PMID: 16690102 DOI: 10.1016/j.scitotenv.2006.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Revised: 02/13/2006] [Accepted: 02/14/2006] [Indexed: 05/06/2023]
Abstract
In this study, ferric oxalate is used to represent the photosensitive Fe(III) complexes as well as the diacid compounds which are at significant concentrations in cloud and rain droplets. Because of the common carboxylate functional group; ferric oxalate is also used as a model to represent humic substances found in natural water. UVA irradiation of aqueous acidic mercuric chloride (pH 1-4) in the presence of an excess of ferrioxalate results in partial reduction of the mercuric ion to elemental mercury. The pseudo-first-order rate constant "kobs" for the photoreduction reaction is pH-dependent as is the yield of residual Hg(II). When exposed to visible irradiation the rate is about 10 times slower and no reaction was observed in the dark. The inferred mechanism of photoreduction involves the reaction of Hg(II) with a secondary photoproduct, the strongly reducing radical anion CO2-*. In the presence of dissolved oxygen, competition for CO2-* between Hg(II) and O2 reduces the rate and efficiency of mercuric ion reduction. The O2-*/HO2 products do not reduce Hg(II). On the contrary, their disproportionation leads to the formation of H2O2 which causes a re-oxidation of Hg(0) at pH values of <or=4. Chloride ion decreases the rate of the reduction of Hg(II).
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Affiliation(s)
- Fuad A Ababneh
- Department of Chemistry, P.O. Box 450 Station A, University of Ottawa, Ottawa, Canada ON K1N 6N5
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23
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Mancinelli V, Decesari S, Facchini MC, Fuzzi S, Mangani F. Partitioning of metals between the aqueous phase and suspended insoluble material in fog droplets. ACTA ACUST UNITED AC 2006; 95:275-90. [PMID: 16477936 DOI: 10.1002/adic.200590033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper discusses the partitioning of metals (K, Na, Ca, Mg, Al, Cu, Fe, Pb and Zn) between the aqueous phase and the suspended insoluble material in fog samples collected in the Po Valley during two extensive fields campaigns. Metals represent on average 11% of the mass of suspended insoluble matter, while the main component is carbon (both organic carbon, OC = 35%, and black carbon, BC = 8%). The unaccounted suspended matter mass is very high, on average 46%, and is attributable to non metallic species, such as O and N and of Si. The principal metals in the insoluble suspended fraction are Fe and Al (2-5%), while the contributions of other metals (Na, Mg, Cu, Pb and Zn) are lower than 1%. Ca and K exhibited high blank values and could not be detected above blank detection limit threshold. The main components in the aqueous phase are NO3- (34%), WSOC (23%), SO4(2-) (18%) and NH4+ (19%), while trace metals and remaining cations and anions accounted for less than 1% of solute mass. The main dissolved trace metals in fog droplets are Zn, Al and Fe, while the main metallic cations are Na and Ca. Fe and Al are the only metals preferentially distributed in the suspended insoluble matter of fog droplets (partitioning ratio respectively 37% and 33%). All other metals are mostly dissolved in the aqueous phase (mean partitioning ratios of Mg, Pb, Zn, Cu and Na are 69%, 70%, 77%, 81% and 87%). These findings are in agreement with literature data on metal speciation in cloud and rain samples. The dependence of partitioning ratios on pH is investigated for the different metals, with only Al showing a clear partitioning ratio decrease with increasing pH. Conversely, the other metals show no dependence or a complex and highly variable behaviour. The partitioning ratio of iron (mean 37%) observed in the Po Valley fog samples is much higher than the water extractable iron in aerosol particles (typically 1-2 %): this fact can be explained by differences in the aerosol sources and composition among sites and by chemical processes in the aqueous phase, such as complexation and redox reactions involving organic ligands (oxalate, or other organic acids as humic-like organic matter) which may promote Fe solubility.
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Affiliation(s)
- Valeriana Mancinelli
- Facoltà di Scienze Ambientali, Università degli studi di Urbino, Campus Scientifico ex Sogesta località Crocicchia, 61029 Urbino, Italy
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24
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Deguillaume L, Leriche M, Desboeufs K, Mailhot G, George C, Chaumerliac N. Transition metals in atmospheric liquid phases: sources, reactivity, and sensitive parameters. Chem Rev 2005; 105:3388-431. [PMID: 16159157 DOI: 10.1021/cr040649c] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Laurent Deguillaume
- Laboratoire de Météorologie Physique, Centre National de la Recherche Scientifique, Université Blaise Pascal, 24 avenue des Landais, 63177 Aubière Cedex, France.
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25
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Willey JD, Whitehead RF, Kieber RJ, Hardison DR. Oxidation of Fe(II) in rainwater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:2579-85. [PMID: 15884352 DOI: 10.1021/es0404522] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Photochemically produced Fe(II) is oxidized within hours under environmentally realistic conditions in rainwater. The diurnal variation between photochemical production and reoxidation of Fe(II) observed in our laboratory accurately mimics the behavior of ferrous iron observed in field studies where the highest concentrations of dissolved Fe(ll) occur in afternoon rain during the period of maximum sunlight intensity followed by gradually decreasing concentrations eventually returning to early morning pre-light values. The experimental work presented here, along with the results of kinetics studies done by others, suggests thatthe primary process responsible for the decline in photochemically produced Fe(II) concentrations is oxidation by hydrogen peroxide. This reaction is first order with respect to both the concentrations of Fe(II) and H2O2. The second-order rate constant determined for six different authentic rain samples varied over an order of magnitude and was always less than or equal to the rate constant determined for this reaction in simple acidic solutions. Oxidation of photochemically produced ferrous iron by other oxidants including molecular oxygen, ozone, hydroxyl radical, hydroperoxyl/superoxide radical, and hexavalent chromium were found to be insignificant under the conditions present in rainwater. This study shows that Fe(II) occurs as at least two different chemical species in rain; photochemically produced Fe(II) that is oxidized over time periods of hours, and a background Fe(II) that is protected against oxidation, perhaps by organic complexation, and is stable against oxidation for days. Because the rate of oxidation of photochemically produced Fe(II) does not increase with increasing rainwater pH, the speciation of this more labile form of Fe(II) is also not controlled by simple hydrolysis reactions.
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Affiliation(s)
- J D Willey
- Department of Chemistry, University of North Carolina at Wilmington, Wilmington, North Carolina 28403-3297, USA.
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26
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Kieber RJ, Skrabal SA, Smith BJ, Willey JD. Organic complexation of Fe(II) and its impact on the redox cycling of iron in rain. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:1576-83. [PMID: 15819212 DOI: 10.1021/es040439h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
More than 80% of the iron(II) present in a dilute (pH 4.5) H2SO4 solution was oxidized by hydrogen peroxide (3 microM) in 24 h, whereas in rainwater Fe(II) remained stable for days indicating that a complexed form of Fe(II) exists in rainwater that protects it against oxidation. When a rain sample was irradiated for 2 h with simulated sunlight, there was a 57 nM increase in Fe(II) resulting from photoreduction of organic Fe(III) complexes. Once irradiation ceased, the photoproduced Fe(II) rapidly oxidized back to its initial concentration of 32 nM prior to irradiation, but not to zero. These photochemical studies demonstrate that during the daytime when sunlight is present there are dynamic interconversions between complexed and uncomplexed Fe(II) and Fe(III) species in rainwater. During the night, after the photochemically produced Fe(II) is reoxidized to Fe(III), virtually all remaining Fe(II) is complexed by ligands which resist further oxidation. Rain samples oxidized under intense UV light lost their ability to stabilize Fe(II), suggesting the ligands stabilizing Fe(II) are organic compounds destroyed by UV-irradiation. Additional UV-irradiation studies demonstrated that on average 25% of the Fe-complexing ligands in rainwater are extremely strong and cannot be detected by spectrophotometric analysis using ferrozine. The stability of organically complexed Fe(II) has important implications for the bioavailability of rainwater-derived Fe in the surface ocean.
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Affiliation(s)
- R J Kieber
- Department of Chemistry and Biochemistry, University of North Carolina at Wilmington, Wilmington, North Carolina 28403-3297, USA.
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27
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Synthesis, characterization, thermodynamic and thermal studies of Zn(II) complexes with di-2-pyridyl ketone salicyloylhydrazone. Polyhedron 2004. [DOI: 10.1016/j.poly.2004.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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28
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Rivera-Figueroa AM, Sumner AL, Finlayson-Pitts BJ. Laboratory studies of potential mechanisms of renoxification of tropospheric nitric acid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:548-554. [PMID: 12630471 DOI: 10.1021/es020828g] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Laboratory studies of the heterogeneous reactions between HNO3 in thin water films on silica surfaces and gaseous NO, CO, CH4, and SO2, proposed as potential "renoxification" mechanisms in the atmosphere, are reported. Transmission FTIR was used to monitor reactants and products on the silica surface and in the gas phase as a function of time. No reaction of CO, CH4, or SO2 was observed; upper limits to the reaction probabilities (gamma(rxn)) are < or = 10(-10) for CO and SO2 and < or = 10(-12) for CH4. However, the reaction of HNO3 with NO does occur with a lower limit for the reaction probability of gammaNO > or = (6 +/- 2) x 10(-9) (2s). The experimental evidence shows that the chemistry is insensitive to whether the substrate is pure silica or borosilicate glass. Nitric acid in its molecular form, and not the nitrate anion form, was shown to be the reactive species, and NH4NO3 was shown not to react with NO. The HNO3-NO reaction could be a significant means of renoxification of nitric acid on the surfaces of buildings and soils in the boundary layer of polluted urban atmospheres. This chemistry may help to resolve some discrepancies between model-predicted ozone and field observations in polluted urban atmospheres.
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Affiliation(s)
- A M Rivera-Figueroa
- Department of Chemistry, University of California at Irvine, Irvine, California 92697-2025, USA
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29
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Ervens B. CAPRAM 2.4 (MODAC mechanism): An extended and condensed tropospheric aqueous phase mechanism and its application. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jd002202] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Herckes P, Lee T, Trenary L, Kang G, Chang H, Collett JL. Organic matter in central California radiation fogs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2002; 36:4777-4782. [PMID: 12487299 DOI: 10.1021/es025889t] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Organic matter was studied in radiation fogs in the San Joaquin Valley of California during the California Regional Particulate Air Quality Study (CRPAQS). Total organic carbon (TOC) concentrations ranged from 2 to 40 ppm of C. While most organic carbon was found in solution as dissolved organic carbon (DOC), 23% on average was not dissolved inside the fog drops. We observe a clear variation of organic matter concentration with droplet size. TOC concentrations in small fog drops (<17 microm) were a factor of 3, on average, higher than TOC concentrations in larger drops. As much as half of the dissolved organic matter was determined to have a molecular weight higher than 500 Da. Deposition fluxes of organic matter in fog drops were high (0.5-4.3 microg of C m(-2) min(-1)), indicating the importance of fog processing as a vector for removal of organic matter from the atmosphere. Deposition velocities of organic matter, however, were usually found to be lower than deposition velocities for fogwater, consistent with the enrichment of the organic matter in smaller fog drops with lower terminal settling velocities.
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Affiliation(s)
- Pierre Herckes
- Atmospheric Science Department, Colorado State University, Fort Collins, Colorado 80523, USA
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31
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Shaked Y, Erel Y, Sukenik A. Phytoplankton-mediated redox cycle of iron in the epilimnion of Lake Kinneret. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2002; 36:460-467. [PMID: 11871562 DOI: 10.1021/es010896n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The biological-mediated redox cycle of Fe was studied in the epilimnion of Lake Kinneret (Sea of Galilee), a mesotrophic lake in Israel. Multi-annual lake water sampling and incubation experiments were carried out to study Fe(III) reduction by natural phytoplankton populations and their possible role in inhibiting Fe(II) oxidation. The reduction characteristics of the dinoflagellate Peridinium gatunense, the dominant lake alga, were further examined in the laboratory. The steady-state concentration of Fe(II) calculated from the assessed reduction and oxidation rates was compared with Fe(II) measured in the lake in order to evaluate the significance of these processes to the lake Fe redox cycle. Nanomolar concentrations of Fe(II) were measured in the oxygenated, high pH, upper water layer of the lake throughout the year. Reduction rates of Fe by natural phytoplankton assemblages ranged between 0.1 and 10 nM/h. The highest reduction rates, determined in dinoflagellate-dominated lake waters, coincided with the highest concentrations of Fe(II) measured simultaneously in the lake. Iron(II) oxidation rates calculated from the measured lake Fe(II) and the obtained reduction rates were significantly slower than published abiotic Fe(II) oxidation rates. Indeed, Fe(II) oxidation rates measured in algal-enriched lake water were 30-fold slowerthan Fe(II) oxidation rates in natural water, demonstrating the potential for Fe(II) stabilization by the lake phytoplankton.
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Affiliation(s)
- Yeala Shaked
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Givat Ram, Israel.
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32
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Johansen AM, Siefert RL, Hoffmann MR. Chemical composition of aerosols collected over the tropical North Atlantic Ocean. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900024] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zhang H, Bartlett RJ. Light-induced disappearance of nitrite in the presence of iron (III). CHEMOSPHERE 2000; 40:411-418. [PMID: 10665407 DOI: 10.1016/s0045-6535(99)00295-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Understanding of rapid disappearance of nitrite in natural waters and its impact on nitrogen natural cycling has remained limited. We found that NO2- disappeared rapidly in pH 3.2 aqueous Fe(III) solutions both in sunlight and in 356 nm light. Quantum yields of the NO2- loss at 356 nm were 0.049-0.14 for initial levels of 10-80 microns NO2- and 200 microns Fe(III). The NO2- loss (at 356 nm) followed apparent first-order kinetics. The rate constants were 1.3 x 10(-3) (40 microns NO2-) and 4.1 x 10(-4) s-1 (80 microns NO2-) for 100 microns Fe(III), and 2.3 x 10(-3) (40 microns NO2-) and 7.5 x 10(-4) s-1 (80 microns NO2(-1)) for 200 microns Fe(III) (t1/2 = 8.7, 27.9, 5.1, and 15.3 min, respectively). The rate constants were directly proportional to [Fe(III)]0 and inversely proportional to [NO2-]0. Agreement between the rate constants obtained experimentally and those calculated mechanistically supports the hypothesis that NO2- was oxidized to NO2 by .OH radicals from photolysis of FeOH2+ complexes, and at high [NO2-]0 (e.g., 80 microns) relative to [Fe(III)]0, hydrolysis of NO2 or N2O4 to form NO3- and NO2- could be significant. This study showed that light and Fe(III)-induced oxidation of NO2- (rate = approximately 10(-1)-10(-2) microns s-1) was more rapid than its direct photolysis (rate = approximately 10(-4) microns s-1), and the photolysis could be a significant source of .OH radicals only in cases where the Fe(III) level is much lower than the NO2- level ([Fe(III)]/[NO2-] < 1/80). This study suggests that the light and Fe(III)-induced oxidation of NO2- would be one potential important pathway responsible for the rapid transformation of NO2- in acidic surface waters, especially those affected by acid-mine drainage or volcanic activities. This study also may be of interest for modeling certain acidic atmospheric water environments.
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Affiliation(s)
- H Zhang
- Department of Plant and Soil Science, University of Vermont, Bulington 05405-0082, USA.
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GAUBEUR I, ROSSI MV, IHA K, SUÁREZ-IHA MEV. Amphoteric behavior of di-2-pyridyl ketone benzoylhydrazone in ethanol-water mixtures. ECLÉTICA QUÍMICA 2000. [DOI: 10.1590/s0100-46702000000100006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The ligand di-2-pyridyl ketone benzoylhydrazone (DPKBH) is widely used for the determination of transition metal ions in environmental samples. Due to its low solubility in water it is used in aqueous-ethanol (1:1) solvent and for higher sensitivity the pH must be properly adjusted. The properties of DPKBH solutions must be known at different ethanol-water percentages in order to achieve higher sensitivity and/or selectivity for metal analysis. The acid-base behavior of this reagent in aqueous-ethanol solvent and the dissociation/ionization constants (pK1 and pK2) of DPKBH have been determined in different aqueous-ethanol solvent mixtures (10, 20, 30 and 50 % V/V of ethanol) from potentiometric titrations at 25.0 ± 0.1° C. As the amount of ethanol increases from 10 to 30% the pK1 and pK2 values increased, but they decreased in 50% of the organic solvent. The results are correlated with the medium composition and its effects.
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Affiliation(s)
| | | | - Koshun IHA
- Instituto Tecnológico da Aeronáutica, Brazil
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35
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Speciation of Fe(II) and Fe(III) with Chromogenic Mixed Reagents by Principal-Component Regression. Microchem J 1999. [DOI: 10.1006/mchj.1999.1796] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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36
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Siefert RL, Johansen AM, Hoffmann MR. Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Labile-Fe(II) and other trace metals. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd100067] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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37
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Lin CJ, Pehkonen SO. Oxidation of elemental mercury by aqueous chlorine (HOCl/OCl−): Implications for tropospheric mercury chemistry. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jd02304] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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38
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Kreidenweis SM, Zhang Y, Taylor GR. The effects of clouds on aerosol and chemical species production and distribution: 2. Chemistry model description and sensitivity analysis. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jd00775] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kleeman MJ, Cass GR, Eldering A. Modeling the airborne particle complex as a source-oriented external mixture. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jd01261] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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40
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Eldering A, Cass GR. Source-oriented model for air pollutant effects on visibility. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95jd02928] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Siefert RL, Webb SM, Hoffmann MR. Determination of photochemically available iron in ambient aerosols. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jd00857] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Anastasio C, Faust BC, Allen JM. Aqueous phase photochemical formation of hydrogen peroxide in authentic cloud waters. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/94jd00085] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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