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Mamontova EA, Mamontov AA. Persistent Organic Pollutants and Suspended Particulate Matter in Snow of Eastern Siberia in 2009-2023: Temporal Trends and Effects of Meteorological Factors and Recultivation Activities at Former Industrial Area. TOXICS 2023; 12:11. [PMID: 38250967 PMCID: PMC10819055 DOI: 10.3390/toxics12010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Suspended particulate matter (SPM), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCP) were studied in the snow cover at urban and suburban localities in the Irkutsk region, Eastern Siberia for their temporal variations in 2009-2023, daily deposition fluxes (DDFs), and effects of some meteorological factors, as well as the effects of different technogenic activities in the industrial area of the former organochlorine enterprises of Usol'ekhimprom. SPM loads at both stations were found to be at a low level of pollution. The levels of HCB, α + γ-HCH, and ∑p,p'-DDX were lower than Russian maximum permissible levels (MPLs) in drinking water, groundwater, and surface water for household drinking and cultural purposes. The sums of all organochlorine compounds studied in snow were higher than the MPL in freshwater water bodies for fishery purposes. The levels of the DDFs of HCHs, DDTs, and heptachlorinated PCB decreased, di- and trichlorinated PCB levels increased, and HCB levels changed at a polynomial line during 2009-2023. The change in the relative composition of PCBs was found as a result of recultivation activities at the industrial area of the former organochlorine enterprise of Usol'ekhimprom. The air humidity and temperature are the key meteorological factors affecting the DDFs of PCBs and OCPs.
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Liu J, Xue S, Jiang C, Zhang Z, Lin Y. Effect of dissolved organic matter on sulfachloropyridazine photolysis in liquid water and ice. WATER RESEARCH 2023; 246:120714. [PMID: 37837902 DOI: 10.1016/j.watres.2023.120714] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/16/2023]
Abstract
Dissolved organic matter (DOM) is an ubiquitous component of environmental snow and ice, which can absorb light and produce reactive species (RS) and thus is of importance in ice photochemistry. The photodegradation of sulfachloropyridazine (SCP) without and with DOM present in liquid water and ice were investigated in this study. The photodegradation rate constants for SCP without DOM present was enhanced by 52.5 % in ice relative to liquid water, likely due to the enhanced role of SCP self-sensitized RS in ice. DOM significantly promoted SCP photolysis in both liquid water and ice, which was mainly attributed to roles of singlet oxygen (1O2) and triplet excited-state DOM (3DOM*) generated from DOM. 1O2 production from DOM was significantly enhanced in ice relative to liquid water. Hydroxyl radical (•OH) production from DOM in ice was similar to those in liquid water. Enhancement in 3DOM* production in ice was observed at low DOM concentrations. Suwannee River Fulvic Acid (SRFA) and Elliott Soil Humic Acid (ESHA) exhibited differences in RS production in liquid water and ice, as well as in enhancement of 1O2 and 3DOM* produced in ice relative to liquid water. DOM induced reaction pathways of SCP different from those without DOM present, and therefore affected toxicity of SCP photoproducts. There were differences in photodegradation pathways of SCP as well as in toxicity of SCP photoproducts between liquid water and ice.
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Affiliation(s)
- Jiyang Liu
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Shuang Xue
- School of Environmental Science, Liaoning University, Shenyang 110036, China.
| | - Caihong Jiang
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Zhaohong Zhang
- School of Environmental Science, Liaoning University, Shenyang 110036, China
| | - Yingzi Lin
- School of Municipal and Environmental Engineering, Jilin Jianzhu University, Changchun 130118, China
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Carena L, Zoppi B, Sordello F, Fabbri D, Minella M, Minero C. Phototransformation of Vanillin in Artificial Snow by Direct Photolysis and Mediated by Nitrite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37269319 DOI: 10.1021/acs.est.3c01931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The photodegradation of vanillin, as a proxy of methoxyphenols emitted by biomass burning, was investigated in artificial snow at 243 K and in liquid water at room temperature. Nitrite (NO2-) was used as a photosensitizer of reactive oxygen and nitrogen species under UVA light, because of its key photochemical role in snowpacks and atmospheric ice/waters. In snow and in the absence of NO2-, slow direct photolysis of vanillin was observed due to back-reactions taking place in the quasi-liquid layer at the ice-grain surface. The addition of NO2- made the photodegradation of vanillin faster, because of the important contribution of photoproduced reactive nitrogen species in vanillin phototransformation. These species triggered both nitration and oligomerization of vanillin in irradiated snow, as the identified vanillin by-products showed. Conversely, in liquid water, direct photolysis was the main photodegradation pathway of vanillin, even in the presence of NO2-, which had negligible effects on vanillin photodegradation. The results outline the different role of iced and liquid water in the photochemical fate of vanillin in different environmental compartments.
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Affiliation(s)
- Luca Carena
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
| | - Beatrice Zoppi
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
| | - Fabrizio Sordello
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
| | - Debora Fabbri
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
| | - Marco Minella
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
| | - Claudio Minero
- Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy
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Tian C, Lv J, Zhang W, Wang H, Chao J, Chai L, Lin Z. Accelerated Degradation of Microplastics at the Liquid Interface of Ice Crystals in Frozen Aqueous Solutions. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chen Tian
- School of Metallurgy and Environment Central South University Changsha 410083 China
| | - Jiaxin Lv
- School of Environment and Energy Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling South China University of Technology Guangzhou Guangdong 510006 China
| | - Wenchao Zhang
- School of Metallurgy and Environment Central South University Changsha 410083 China
| | - Han Wang
- School of Metallurgy and Environment Central South University Changsha 410083 China
| | - Jin Chao
- School of Metallurgy and Environment Central South University Changsha 410083 China
| | - Liyuan Chai
- School of Metallurgy and Environment Central South University Changsha 410083 China
| | - Zhang Lin
- School of Metallurgy and Environment Central South University Changsha 410083 China
- Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution Changsha 410083 P. R. China
- School of Environment and Energy Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling South China University of Technology Guangzhou Guangdong 510006 China
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Tian C, Lv J, Zhang W, Wang H, Chao J, Chai L, Lin Z. Accelerated Degradation of Microplastics at the Liquid Interface of Ice Crystals in Frozen Aqueous Solutions. Angew Chem Int Ed Engl 2022; 61:e202206947. [PMID: 35642755 DOI: 10.1002/anie.202206947] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Indexed: 12/12/2022]
Abstract
Microplastics (MPs) are one of the emerging contaminants in environmental media, and they have raised great concern because they are resistant to degradation and persist in ecosystems. Although numerous advanced technologies have been developed, suitable technologies are still lacking for degradation of widespread MPs in the natural environment. We have discovered that MPs can be degraded exceptionally rapidly in frozen environments. Taking polystyrene (PS) as an example, its degradation rate in ice (-20 °C) is surprisingly competitive to most artificial technologies. PS particles are trapped and squeezed to achieve excited state (3 PS*) in the narrow space of the liquid layer between ice crystals, which further react with the highly concentrated dioxygen to selectively produce singlet oxygen (1 O2 ). The 1 O2 boosts PS oxidation in the liquid layer thus further causing accelerated degradation at freezing temperature. This finding offers a highly efficient pathway for degradation of MPs and it sheds light on an unusual MPs disposal mechanisms in nature.
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Affiliation(s)
- Chen Tian
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Jiaxin Lv
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Wenchao Zhang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Han Wang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Jin Chao
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Liyuan Chai
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Zhang Lin
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China.,Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, P. R. China.,School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, China
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6
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Ossola R, Jönsson OM, Moor K, McNeill K. Singlet Oxygen Quantum Yields in Environmental Waters. Chem Rev 2021; 121:4100-4146. [PMID: 33683861 DOI: 10.1021/acs.chemrev.0c00781] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Singlet oxygen (1O2) is a reactive oxygen species produced in sunlit waters via energy transfer from the triplet states of natural sensitizers. There has been an increasing interest in measuring apparent 1O2 quantum yields (ΦΔ) of aquatic and atmospheric organic matter samples, driven in part by the fact that this parameter can be used for environmental fate modeling of organic contaminants and to advance our understanding of dissolved organic matter photophysics. However, the lack of reproducibility across research groups and publications remains a challenge that significantly limits the usability of literature data. In the first part of this review, we critically evaluate the experimental techniques that have been used to determine ΦΔ values of natural organic matter, we identify and quantify sources of errors that potentially explain the large variability in the literature, and we provide general experimental recommendations for future studies. In the second part, we provide a qualitative overview of known ΦΔ trends as a function of organic matter type, isolation and extraction procedures, bulk water chemistry parameters, molecular and spectroscopic organic matter features, chemical treatments, wavelength, season, and location. This review is supplemented with a comprehensive database of ΦΔ values of environmental samples.
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Affiliation(s)
- Rachele Ossola
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Oskar Martin Jönsson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Kyle Moor
- Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, 84322 Logan, Utah, United States
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
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Li T, Huang Y, Wei G, Zhang YN, Zhao Y, Crittenden JC, Li C. Quantitative structure-activity relationship models for predicting singlet oxygen reaction rate constants of dissociating organic compounds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 735:139498. [PMID: 32485452 DOI: 10.1016/j.scitotenv.2020.139498] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/26/2020] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
As singlet oxygen (1O2) is ubiquitous in the environment, 1O2-involved oxidation may play an important role in the transformation and fate of organic pollutants. Accordingly, the reaction rate constants (k1O2) of organic compounds with 1O2 are important to determine the environmental fate and persistence assessment of organic pollutants. However, currently there are limited k1O2 data available, especially for organic chemicals with different charged (deprotonated/protonated) forms. Herein three quantitative structure-activity relationship (QSAR) models (one comprehensive model and two models for neutral and deprotonated molecules) were created for predicting aqueous k1O2 values for diversely dissociating molecules. The models include larger datasets (180 chemicals) and have wider applicability domain than previous ones. Molecular structural characteristics (only half-wave potential is present in both models) determining the 1O2 reaction rate of neutral and deprotonated molecules vary greatly. The comparison results of predicting k1O2 values of organic compounds at certain pH conditions show that the combination of the QSAR models for neutral and deprotonated molecules has advantages over the comprehensive QSAR model. This work is the first study to predict k1O2 for a wide variety of neutral and deprotonated molecules and provides an important tool for assessing the fate of organic pollutants in aquatic environments.
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Affiliation(s)
- Tiantian Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yu Huang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Gaoliang Wei
- Key Laboratory of Groundwater Resources and Environment (Ministry of Education), College of New Energy and Environment, Jilin University, Changchun 130021, China
| | - Ya-Nan Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yuanhui Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - John C Crittenden
- Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Chao Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China.
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8
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Menacherry SPM, Min DW, Jeong D, Aravindakumar CT, Lee W, Choi W. Halide-induced dissolution of lead(IV) oxide in frozen solution. JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121298. [PMID: 31585282 DOI: 10.1016/j.jhazmat.2019.121298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/09/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
The dark dissolution behavior of plattnerite (ß-PbO2) was investigated in frozen solutions containing halide ions and compared with those in aqueous solution. The amount of dissolved lead in the frozen solutions varied depending on the solution pH and the kind and concentration of halide ions. The presence of bromide and iodide ions enhanced the dissolution of lead in the aqueous phase, whereas the effect of chloride was insignificant. Compared with the aqueous phase dissolution, ß-PbO2 dissolution in the frozen solution was slightly enhanced in the presence of bromide but suppressed in the presence of iodide. Iodide ions seemed to be relatively more trapped in the bulk ice (ice-crystal lattice) than bromide ions, which might be related to the suppressed dissolution of lead oxide in the presence of iodide. The co-existence of bromide (or iodide) and chloride ions in the frozen solution enhanced the dissolution of lead, which seems to be enabled by an additional reaction pathway involving the formation of mixed halide radicals, whereas such kind of synergistic enhancements were not observed in aqueous solution. The halide-induced lead oxide dissolution in frozen solutions can be related to the behavior of lead ions found in various media of frozen environments.
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Affiliation(s)
- Sunil Paul M Menacherry
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea; School of Environmental Sciences, Mahatma Gandhi University, Kottayam, India
| | - Dae Wi Min
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Daun Jeong
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | | | - Woojin Lee
- Department of Civil and Environmental Engineering, Nazarbayev University, Astana, 010000, Kazakhstan
| | - Wonyong Choi
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
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9
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Su L, Caywood LM, Sivey JD, Dai N. Sunlight Photolysis of Safener Benoxacor and Herbicide Metolachlor as Mixtures on Simulated Soil Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6784-6793. [PMID: 31132254 DOI: 10.1021/acs.est.9b01243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Benoxacor is a safener paired with the high-use herbicide S-metolachlor. Commercial formulations containing both compounds are sprayed onto soil pre-emergence to enhance yields of corn. In this study, we evaluated the sunlight photolysis of metolachlor and benoxacor, individually and as mixtures, in three different reaction environments: in water and on two soil-simulating surfaces (quartz and kaolinite). When irradiated individually, benoxacor degraded at least 19 times faster than metolachlor in each reaction environment, consistent with its higher molar absorptivity within the solar spectrum than metolachlor. When metolachlor and benoxacor were irradiated as mixtures, benoxacor promoted metolachlor degradation on quartz and, to a lesser extent, in water, but not on kaolinite. On quartz, at a benoxacor/metolachlor molar ratio of 0.1:1, metolachlor degraded 1.8 times faster than in the absence of benoxacor; as the benoxacor/metolachlor ratio increased, metolachlor degradation rate also increased. The photolysis rate of benoxacor depended on its initial surface concentration and was promoted by metolachlor. Benoxacor photoproducts were capable of absorbing sunlight and serving as photosensitizers for metolachlor degradation. These results illustrate how a safener can influence the photochemistry of its coformulated herbicide and suggest that such mixture effects should be considered when evaluating the environmental fate of agrochemicals.
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Affiliation(s)
- Lei Su
- Department of Civil, Structural and Environmental Engineering , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
| | - Leandra M Caywood
- Department of Chemical and Materials Engineering , University of Alabama in Huntsville , Huntsville , Alabama 35899 , United States
| | - John D Sivey
- Department of Chemistry , Towson University , Towson , Maryland 21252 , United States
| | - Ning Dai
- Department of Civil, Structural and Environmental Engineering , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
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10
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Menacherry SPM, Kim K, Lee W, Choi CH, Choi W. Ligand-Specific Dissolution of Iron Oxides in Frozen Solutions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13766-13773. [PMID: 30395706 DOI: 10.1021/acs.est.8b04484] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The freezing-enhanced dissolution of iron oxides by various ligands has been recently proposed as a new mechanism that may influence the supply of bioavailable iron in frozen environments. The ligand-induced dissolution of iron oxides is sensitively affected by the kind and concentration of ligands, pH, and kind of iron oxides. While most ligands are thought to be freeze-concentrated in the ice grain boundary region along with iron oxides to enhance the iron dissolution, this study found that some ligands, such as ascorbic acid, suppress the iron dissolution in frozen solution relative to that in aqueous solution. Such ligands are proposed to be preferentially incorporated in the ice lattice bulk and not freeze-concentrated in the liquid-like grain boundary. The experimental analysis estimated that the ionized forms of ligands (e.g., iodide ions) are hardly present in the ice bulk region (<3%) and enhance the iron dissolution in frozen solution (relative to that in aqueous solution), whereas some neutral ligands (e.g., undissociated ascorbic acid) are significantly trapped in the ice bulk (>50%) and suppress the iron dissolution compared to the aqueous counterpart. The present results reveal that the ligand-induced dissolution of iron oxide in frozen solution is not always enhanced relative to aqueous solution but depends upon the kind of ligand and experimental conditions.
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Affiliation(s)
- Sunil Paul M Menacherry
- Division of Environmental Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Korea
| | - Kitae Kim
- Korea Polar Research Institute (KOPRI) , Incheon 21990 , Korea
| | - Woojin Lee
- Department of Civil and Environmental Engineering , Nazarbayev University , Astana 010000 , Kazakhstan
| | - Cheol Ho Choi
- Department of Chemistry , Kyungpook National University , Daegu 41566 , Korea
| | - Wonyong Choi
- Division of Environmental Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Korea
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Hullar T, Magadia D, Anastasio C. Photodegradation Rate Constants for Anthracene and Pyrene Are Similar in/on Ice and in Aqueous Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12225-12234. [PMID: 30251528 DOI: 10.1021/acs.est.8b02350] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Snowpacks contain a variety of chemicals, including organic pollutants such as toxic polycyclic aromatic hydrocarbons (PAHs). While PAHs undergo photodegradation in snow and ice, the rates of these reactions remain in debate. Some studies report that photochemical reactions in snow proceed at rates similar to those expected in a supercooled aqueous solution, but other studies report faster reaction rates, particularly at the air-ice interface (i.e., the quasi-liquid layer, or QLL). In addition, one study reported a surprising nonlinear dependence on photon flux. Here we examine the photodegradation of two common PAHs, anthracene and pyrene, in/on ice and in solution. For a given PAH, rate constants are similar in aqueous solution, in internal liquid-like regions of ice, and at the air-ice interface. In addition, we find the expected linear relationship between reaction rate constant and photon flux. Our results indicate that rate constants for the photochemical loss of PAHs in, and on, snow and ice are very similar to those in aqueous solution, with no enhancement at the air-ice interface.
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Affiliation(s)
- Ted Hullar
- Department of Land, Air and Water Resources , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
| | - Danielle Magadia
- Department of Land, Air and Water Resources , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
- Now at California Department of Food and Agriculture , 3292 Meadowview , Sacramento , California 95832 , United States
| | - Cort Anastasio
- Department of Land, Air and Water Resources , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States
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Bokare AD, Choi W. Singlet-Oxygen Generation in Alkaline Periodate Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:14392-400. [PMID: 26594871 DOI: 10.1021/acs.est.5b04119] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A nonphotochemical generation of singlet oxygen ((1)O2) using potassium periodate (KIO4) in alkaline condition (pH > 8) was investigated for selective oxidation of aqueous organic pollutants. The generation of (1)O2 was initiated by the spontaneous reaction between IO4(-) and hydroxyl ions, along with a stoichiometric conversion of IO4(-) to iodate (IO3(-)). The reactivity of in-situ-generated (1)O2 was monitored by using furfuryl alcohol (FFA) as a model substrate. The formation of (1)O2 in the KIO4/KOH system was experimentally confirmed using electron spin resonance (ESR) measurements in corroboration with quenching studies using azide as a selective (1)O2 scavenger. The reaction in the KIO4/KOH solution in both oxic and anoxic conditions initiated the generation of superoxide ion as a precursor of the singlet oxygen (confirmed by using superoxide scavengers), and the presence of molecular oxygen was not required as a precursor of (1)O2. Although hydrogen peroxide had no direct influence on the FFA oxidation process, the presence of natural organic matter, such as humic and fulvic acids, enhanced the oxidation efficiency. Using the oxidation of simple organic diols as model compounds, the enhanced (1)O2 formation is attributed to periodate-mediated oxidation of vicinal hydroxyl groups present in humic and fulvic constituent moieties. The efficient and simple generation of (1)O2 using the KIO4/KOH system without any light irradiation can be employed for the selective oxidation of aqueous organic compounds under neutral and near-alkaline conditions.
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Affiliation(s)
- Alok D Bokare
- School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea
| | - Wonyong Choi
- School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH) , Pohang 790-784, Korea
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