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Buckley S, Leresche F, Norris K, Rosario-Ortiz FL. Role of Direct and Sensitized Photolysis in the Photomineralization of Dissolved Organic Matter and Model Chromophores to Carbon Dioxide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:13808-13819. [PMID: 39047179 DOI: 10.1021/acs.est.4c01530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
This study addresses the fundamental processes that drive the photomineralization of dissolved organic matter (DOM) to carbon dioxide (CO2), deconvoluting the role of direct and sensitized photolysis. Here, a suite of DOM isolates and model compounds were exposed to simulated sunlight in the presence of various physical and chemical quenchers to assess the magnitude, rate, and extent of direct and sensitized photomineralization to CO2. Results suggest that CO2 formation occurs in a biphasic kinetic system, with fast production occurring within the first 3 h, followed by slower production thereafter. Notably, phenol model chromophores were the highest CO2 formers and, when conjugated with carboxylic functional groups, exhibited a high efficiency for CO2 formation relative to absorbed light. Simple polycarboxylated aromatic compounds included in this study were shown to be resistant to photomineralization. Quencher results suggest that direct photolysis and excited triplet state sensitization may be largely responsible for CO2 photoproduction in DOM, while singlet oxygen and hydroxyl radical sensitization may play a limited role. After 3 h of irradiation, the CO2 formation rate significantly decreased, and the role of sensitized reactions in CO2 formation increased. Together, the results from this study advance the understanding of the fundamental reactions driving DOM photomineralization to CO2, which is an important part of the global carbon cycle.
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Affiliation(s)
- Shelby Buckley
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Frank Leresche
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Kari Norris
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
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2
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Korak JA, McKay G. Critical review of fluorescence and absorbance measurements as surrogates for the molecular weight and aromaticity of dissolved organic matter. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 39058291 DOI: 10.1039/d4em00183d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Dissolved organic matter (DOM) is ubiquitous in aquatic environments and challenging to characterize due to its heterogeneity. Optical measurements (i.e., absorbance and fluorescence spectroscopy) are popular characterization tools, because they are non-destructive, require small sample volumes, and are relatively inexpensive and more accessible compared to other techniques (e.g., high resolution mass spectrometry). To make inferences about DOM chemistry, optical surrogates have been derived from absorbance and fluorescence spectra to describe differences in spectral shape (e.g., E2:E3 ratio, spectral slope, fluorescence indices) or quantify carbon-normalized optical responses (e.g., specific absorbance (SUVA) or specific fluorescence intensity (SFI)). The most common interpretations relate these optical surrogates to DOM molecular weight or aromaticity. This critical review traces the genesis of each of these interpretations and, to the extent possible, discusses additional lines of evidence that have been developed since their inception using datasets comparing diverse DOM sources or strategic endmembers. This review draws several conclusions. More caution is needed to avoid presenting surrogates as specific to either molecular weight or aromaticity, as these physicochemical characteristics are often correlated or interdependent. Many surrogates are proposed using narrow contexts, such as fractionation of a limited number of samples or dependence on isolates. Further study is needed to determine if interpretations are generalizable to whole-waters. Lastly, there is a broad opportunity to identify why endmembers with low abundance of aromatic carbon (e.g., effluent organic matter, Antarctic lakes) often do not follow systematic trends with molecular weight or aromaticity as observed in endmembers from terrestrial environments with higher plant inputs.
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Affiliation(s)
- Julie A Korak
- Department of Civil, Environmental, and Architectural Engineering, USA.
- Environmental Engineering Program, University of Colorado, Boulder, CO, USA
| | - Garrett McKay
- Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, TX 77843, USA.
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3
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Minakata D. Development of an Elementary Reaction-Based Kinetic Model to Predict the Aqueous-Phase Fate of Organic Compounds Induced by Reactive Free Radicals. Acc Chem Res 2024; 57:1658-1669. [PMID: 38804206 DOI: 10.1021/acs.accounts.4c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
ConspectusAqueous-phase free radicals such as reactive oxygen, halogen, and nitrogen species play important roles in the fate of organic compounds in the aqueous-phase advanced water treatment processes and natural aquatic environments under sunlight irradiation. Predicting the fate of organic compounds in aqueous-phase advanced water treatment processes and natural aquatic environments necessitates understanding the kinetics and reaction mechanisms of initial reactions of free radicals with structurally diverse organic compounds and other reactions. Researchers developed conventional predictive models based on experimentally measured transformation products and determined reaction rate constants by fitting with the time-dependent concentration profiles of species due to difficulties in their measurements of unstable intermediates. However, the empirical treatment of lumped reaction mechanisms had a model prediction limitation with respect to the specific parent compound's fate. We use ab initio and density functional theory quantum chemical computations, numerical solutions of ordinary differential equations, and validation of the outcomes of the model with experiments. Sensitivity analysis of reaction rate constants and concentration profiles enables us to identify an important elementary reaction in formating the transformation product. Such predictive elementary reaction-based kinetics models can be used to screen organic compounds in water and predict their potentially toxic transformation products for a specific experimental investigation.Over the past decade, we determined linear free energy relationships (LFERs) that bridge the kinetic and thermochemical properties of reactive oxygen species such as hydroxyl radicals (HO•), peroxyl radicals (ROO•), and singlet oxygen (1O2); reactive halogen species such as chlorine radicals (Cl•) and bromine radicals (Br•); reactive nitrogen species (NO2•); and carbonate radicals (CO3•-). We used literature-reported experimental rate constants as kinetic information. We considered the theoretically calculated aqueous-phase free energy of activation or reaction to be a kinetic or a thermochemical property, and obtained via validated ab initio or density functional theory-based quantum chemical computations using explicit and implicit solvation models. We determined rate-determining reaction mechanisms involved in reactions by observing robust LFERs. The general accuracy of LFERs to predict aqueous-phase rate constants was within a difference of a factor of 2-5 from experimental values.We developed elementary reaction-based kinetic models and predicted the fate of acetone induced by HO• in an advanced water treatment process and methionine by photochemically produced reactive intermediates in sunlit fresh waters. We provided mechanistic insight into peroxyl radical reaction mechanisms and critical roles in the degradation of acetone and the formation of transformation products. We highlighted different roles of triplet excited states of two surrogate CDOMs, 1O2, and HO•, in methionine degradation. Predicted transformation products were compared to those obtained via benchtop experiments to validate our elementary reaction-based kinetic models. Predicting the reactivities of reactive halogen and nitrogen species implicates our understanding of the formation of potentially toxic halogen- and nitrogen-containing transformation products during water treatment processes and in natural aquatic environments.
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Affiliation(s)
- Daisuke Minakata
- Department of Civil, Environmental, and Geospatial Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
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Du R, Wen J, Huang J, Zhang Q, Shi X, Wang B, Deng S, Yu G. Dissolved organic matter isolates obtained by solid phase extraction exhibit higher absorption and lower photo-reactivity: Effect of components. WATER RESEARCH 2024; 256:121604. [PMID: 38640562 DOI: 10.1016/j.watres.2024.121604] [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: 01/11/2024] [Revised: 03/24/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024]
Abstract
Notable differences in photo-physical and chemical properties were found between bulk water and solid phase extraction (SPE) isolates for dissolved organic matter (DOM). The moieties extracted using modified styrene divinylbenzene cartridges, which predominantly consist of conjugated aromatic molecules like humic acids, contribute mainly to light absorption but exhibit lower quantum yields of fluorescence and photo-produced reactive intermediates (PPRIs). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed lignin as the moieties displaying most significant variance in abundance. In Van Krevelen-Spearman plot, we observed molecules positively or negatively correlated with DOM's optical and photochemical properties (including SUVA254, steady-state concentrations of ·OH, 1O2 quantum yield, etc.) were confined to specific regions, which can be delineated using a threshold modified aromaticity index (AImod) of 0.3. Based on the relationships between optical properties and PPRI production, it is suggested that the energy gap between ground state and excited singlet state (△ES1→S0), governing the inner conversion rate, serves as a determinant for apparent quantum yield of PPRIs in DOM, with intra-molecular charge transfer (CT) interactions potentially playing a pivotal role. Regarding DOM's photoreactivity with pollutants, this study has revealed, for the first time, that protein/amino sugars/amino acids could act as antioxidant groups in addition to phenols on the photolysis of sulfadiazine. These findings provide valuable insights into DOM photochemistry and are expected to stimulate further research in this area.
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Affiliation(s)
- Roujia Du
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jiaqi Wen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jun Huang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Qianxin Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Xiaoyu Shi
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Bin Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Shubo Deng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Gang Yu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing, 100084, China; Advanced Interdisciplinary Institute of Environmental and Ecology, Beijing Normal University, Zhuhai, 519087, China.
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5
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Buckley S, McKay G, Leresche F, Rosario-Ortiz F. Inferring the Molecular Basis for Dissolved Organic Matter Photochemical and Optical Properties. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9040-9050. [PMID: 38743693 DOI: 10.1021/acs.est.3c10881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Despite the widespread use of photochemical and optical properties to characterize dissolved organic matter (DOM), a significant gap persists in our understanding of the relationship among these properties. This study infers the molecular basis for the optical and photochemical properties of DOM using a comprehensive framework and known structural moieties within DOM. Utilizing Suwannee River Fulvic Acid (SRFA) as a model DOM, carboxylated aromatics, phenols, and quinones were identified as dominant contributors to the absorbance spectra, and phenols, quinones, aldehydes, and ketones were identified as major contributors to radiative energy pathways. It was estimated that chromophores constitute ∼63% w/w of dissolved organic carbon in SRFA and ∼47% w/w of overall SRFA. Notably, estimations indicate the pool of fluorescent compounds and photosensitizing compounds in SRFA are likely distinct from each other at wavelengths below 400 nm. This perspective offers a practical tool to aid in the identification of probable chemical groups when interpreting optical and photochemical data and challenges the current "black box" thinking. Instead, DOM photochemical and optical properties can be closely estimated by assuming the DOM is composed of a mixture of individual compounds.
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Affiliation(s)
- Shelby Buckley
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Garrett McKay
- Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
| | - Frank Leresche
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Fernando Rosario-Ortiz
- Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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6
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Du P, Tang K, Yang B, Mo X, Wang J. Reassessing the Quantum Yield and Reactivity of Triplet-State Dissolved Organic Matter via Global Kinetic Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5856-5865. [PMID: 38516968 DOI: 10.1021/acs.est.4c00214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Measuring the quantum yield and reactivity of triplet-state dissolved organic matter (3DOM*) is essential for assessing the impact of DOM on aquatic photochemical processes. However, current 3DOM* quantification methods require multiple fitting steps and rely on steady-state approximations under stringent application criteria, which may introduce certain inaccuracies in the estimation of DOM photoreactivity parameters. Here, we developed a global kinetic model to simulate the reaction kinetics of the hv/DOM system using four DOM types and 2,4,6-trimethylphenol as the probe for 3DOM*. Analyses of residuals and the root-mean-square error validated the exceptional precision of the new model compared to conventional methods. 3DOM* in the global kinetic model consistently displayed a lower quantum yield and higher reactivity than those in local regression models, indicating that the generation and reactivity of 3DOM* have often been overestimated and underestimated, respectively. The global kinetic model derives parameters by simultaneously fitting probe degradation kinetics under different conditions and considers the temporally increasing concentrations of the involved reactive species. It minimizes error propagation and offers insights into the interactions of different species, thereby providing advantages in accuracy, robustness, and interpretability. This study significantly advances the understanding of 3DOM* behavior and provides a valuable kinetic model for aquatic photochemistry research.
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Affiliation(s)
- Penghui Du
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Kexin Tang
- Center of Water Resources and Environment, School of Civil Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Biwei Yang
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Xiaohan Mo
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- School of Urban Planning and Design, Peking University Shenzhen Graduate School, Peking University, Shenzhen, Guangdong 518055, China
| | - Junjian Wang
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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7
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Jiang H, Zhao M, Hong W, Song W, Yan S. Mechanistic and Kinetic Consideration of the Photochemically Generated Oxidative Organic Radicals in Dissolved Black Carbon Solutions under Simulated Solar Irradiation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:760-770. [PMID: 38149879 DOI: 10.1021/acs.est.3c07216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
The photochemically generated oxidative organic radicals (POORs) in dissolved black carbon (DBC) was investigated and compared with that in dissolved organic matter (DOM). POORs generated in DBC solutions exhibited higher one-electron reduction potential values (1.38-1.56 V) than those in DOM solutions (1.22-1.38 V). We found that the photogeneration of POORs from DBC is enhanced with dissolved oxygen (DO) increasing, while the inhibition of POORs is observed in reference to DOM solution. The behavior of the one-electron reducing species (DBC•-/DOM•-) was employed to explain this phenomenon. The experimental results revealed that the DO concentration had a greater effect on DBC•- than on DOM•-. Low DO levels led to a substantial increase in the steady-state concentration of DBC•-, which quenched the POORs via back-electron reactions. Moreover, the contribution of POORs to the degradation of 19 emerging organic contaminants (EOCs) in sunlight-exposed DBC and DOM solutions was estimated. The findings indicate that POORs play an important role in the photodegradation of EOCs previously known to react with triplets, especially in DBC solutions. Compared to DOM solutions, POOR exhibits a lower but considerable contribution to EOC attenuation. This study enhances the understanding of pollutant fate in aquatic environments by highlighting the role of DBC in photochemical pollutant degradation and providing insights into pollutant transformation mechanisms involving POORs.
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Affiliation(s)
- Hongyu Jiang
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
| | - Mengzhe Zhao
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
| | - Wenjie Hong
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
| | - Weihua Song
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
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8
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Kim P, Boothby C, Grassian VH, Continetti RE. Photoinduced Reactions of Nitrate in Aqueous Microdroplets by Triplet Energy Transfer. J Phys Chem Lett 2023; 14:10677-10684. [PMID: 37988598 DOI: 10.1021/acs.jpclett.3c02178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
In-situ Raman spectroscopy of single levitated charged aqueous microdroplets irradiated by dual-beam (266 and 532 nm) lasers demonstrates that the nitrate anion (NO3-) can be depleted in the droplet through an energy transfer mechanism following excitation of sulfanilic acid (SA), a UV-absorbing aromatic organic compound. Upon 266 nm irradiation, a fast decrease of the NO3- concentration was observed when SA is present in the droplet. This photoinduced reaction occurs without the direct photolysis of NO3-. Instead, the rate of NO3- depletion was found to depend on the initial concentration of SA and the pH of the droplet. Based on absorption-emission spectral analysis and excited-state energy calculations, triplet-triplet energy transfer between SA and NO3- is proposed as the underlying mechanism for the depletion of NO3- in aqueous microdroplets. These results suggest that energy transfer mechanisms initiated by light-absorbing organic molecules may play a significant role in NO3- photochemistry.
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Affiliation(s)
- Pyeongeun Kim
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0340, United States
| | - Christian Boothby
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0340, United States
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0340, United States
| | - Robert E Continetti
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0340, United States
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9
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Zhou R, Liu J, Zhou C, Zhang X. Phototransformation of Lignin-related Compounds in Chromophoric Dissolved Organic Matter Solutions. WATER RESEARCH 2023; 245:120586. [PMID: 37717330 DOI: 10.1016/j.watres.2023.120586] [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: 06/17/2023] [Revised: 08/25/2023] [Accepted: 09/04/2023] [Indexed: 09/19/2023]
Abstract
Lignin is a major terrestrial source of chromophoric dissolved organic matter (CDOM), and studying the phototransformation of lignin monomers and their related compounds can enhance our understanding of CDOM intramolecular interactions. Coniferyl aldehyde (Coni) and sinapaldehyde (Sina) form ground-state complexes with CDOM, with equilibrium constants of 7,800 (± 1,800) and 20,000 (± 2,000) M-1, respectively. In comparison, vanillin (Van) exhibits minimal affinity for CDOM complexation. The bimolecular reaction rate constants between singlet oxygen (1O2) and these phenolic carbonyl compounds ranged from 0.46 (± 0.02) to 1.8 (± 0.1) × 107 M-1s-1, which is approximately one order of magnitude lower than their reaction rate constants (0.51 (± 0.02)-1.25 (± 0.02) × 108 M-1s-1) with the triplet excited state of CDOM (3CDOM*). In acidic CDOM solutions (pH 5.0), 1O2, H2O2, and organic peroxyl radicals had negligible impact on the transformation. Comparing the initial transformation rate in the presence and in the absence of NaN3 or furfuryl alcohol led to an overestimation of the contribution of 1O2 to the transformation of Van, Coni, or Sina. 3CDOM* scavengers could not fully inhibit the transformation of Coni or Sina. The remaining transformation is considered to arise from either the unquenched intra-CDOM phase 3CDOM* or a fraction of Coni⊂CDOM or Sina⊂CDOM complex, which underwent intramolecular photoinduced chemical reactions.
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Affiliation(s)
- Ruiya Zhou
- School of Resources and Environmental Science, Wuhan University, Wuhan, 430079, P.R. China
| | - Juan Liu
- School of Resources and Environmental Science, Wuhan University, Wuhan, 430079, P.R. China
| | - Chi Zhou
- Hubei Water Resources Research Institute, Wuhan, 430070, P.R. China.
| | - Xu Zhang
- School of Resources and Environmental Science, Wuhan University, Wuhan, 430079, P.R. China.
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10
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Kong Q, Ye L, Pan Y, Zhou Y, Lei Y, Zeng Z, Chen S, Yao L, Zhang X, Westerhoff P, Yang X. Photochemical Transformation of Free Chlorine Induced by Triplet State Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37428984 DOI: 10.1021/acs.est.3c02458] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Photolysis of free chlorine is an increasingly recognized approach for effectively inactivating microorganisms and eliminating trace organic contaminants. However, the impact of dissolved organic matter (DOM), which is ubiquitous in engineered water systems, on free chlorine photolysis is not yet well understood. In this study, triplet state DOM (3DOM*) was found to cause the decay of free chlorine for the first time. By using laser flash photolysis, the scavenging rate constants of triplet state model photosensitizers by free chlorine at pH 7.0 were determined to be in the range of (0.26-3.33) × 109 M-1 s-1. 3DOM*, acting as a reductant, reacted with free chlorine at an estimated reaction rate constant of 1.22(±0.22) × 109 M-1 s-1 at pH 7.0. This study revealed an overlooked pathway of free chlorine decay during UV irradiation in the presence of DOM. Besides the DOM's light screening ability and scavenging of radicals or free chlorine, 3DOM* played an important role in the decay of free chlorine. This reaction pathway accounted for a significant proportion of the decay of free chlorine, ranging from 23 to 45%, even when DOM concentrations were below 3 mgC L-1 and a free chlorine dose of 70 μM was present during UV irradiation at 254 nm. The generation of HO• and Cl• from the oxidation of 3DOM* by free chlorine was confirmed by electron paramagnetic resonance and quantified by chemical probes. By inputting the newly observed pathway in the kinetics model, the decay of free chlorine in UV254-irradiated DOM solution can be well predicted.
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Affiliation(s)
- Qingqing Kong
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Lei Ye
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yanheng Pan
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yangjian Zhou
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yu Lei
- Key Laboratory of Photochemistry, Institute of Chemistry Chinese Academy of Sciences, Beijing National Laboratory for Molecular Sciences, Beijing 100190, China
| | - Zihan Zeng
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Siqi Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Liaoliao Yao
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Xinran Zhang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287-3005, United States
| | - Xin Yang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
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11
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Wang J, Zhang X, Fan L, Su L, Zhao YH. Photolysis mechanism of eleven insecticides under simulated sunlight irradiation: Kinetics, pathway and QSAR. CHEMOSPHERE 2023; 334:138968. [PMID: 37211161 DOI: 10.1016/j.chemosphere.2023.138968] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/23/2023]
Abstract
Insecticides are widely used in crop protection against insects and frequently detected in aquatic environment. Photolysis kinetics are directly related with exposure assessment and risk assessment. However, the photolysis mechanism of neonicotinoid insecticides with different structures has not been studied and compared systematically in the literature. In this paper, the photolysis rate constants in water were determined for eleven insecticides under irradiation of simulated sunlight. At the same time, the photolysis mechanism and effect of dissolved organic matter (DOM) on their photolysis were studied. The results showed that photolysis rates of eleven insecticides vary in a large range. The photolysis rates of nitro-substituted neonicotinoids and butenolide insecticide are much faster than that of cyanoimino-substituted neonicotinoids and sulfoximine insecticide. The ROS scavenging activity assays reveal that direct photolysis dominates the degradation of seven insecticides and, on the other hand, self-sensitized photolysis dominates four insecticides. The shading-effect from DOM can reduce the direct photolysis rates, on the other hand, ROSs generated by triplet-state DOM (3DOM*) can also accelerate photolysis of insecticides. According to the photolytic products identified from HPLC-MS, these eleven insecticides have different photolysis pathways. Six insecticides are degraded from the removal of nitro group from their parent compounds and four insecticides are degraded through ·OH reaction or singlet oxygen (1O2) reaction. QSAR (quantitative structure-activity relationship) analysis showed that photolysis rate was directly related to the energy gap between the highest occupied molecular orbital to the lowest unfilled molecular orbital (Egap = ELUMO-EHOMO) and dipole moment (δ). These two descriptors reflect the chemical stability and reactivity of insecticides. The pathways developed from identified products and the molecular descriptors of QSAR models can well verify the photolysis mechanisms of eleven insecticides.
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Affiliation(s)
- Jia Wang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Xujia Zhang
- Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin, 150025, China
| | - Lingyun Fan
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China; Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin, 150025, China
| | - Limin Su
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Yuan H Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, 130117, China.
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12
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Chen X, Wang J, Wu H, Zhu Z, Zhou J, Guo H. Trade-off effect of dissolved organic matter on degradation and transformation of micropollutants: A review in water decontamination. JOURNAL OF HAZARDOUS MATERIALS 2023; 450:130996. [PMID: 36867904 DOI: 10.1016/j.jhazmat.2023.130996] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/24/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The degradation of micropollutants by various treatments is commonly affected by the ubiquitous dissolved organic matter (DOM) in the water environment. To optimize the operating conditions and decomposition efficiency, it is necessary to consider the impacts of DOM. DOM exhibits varied behaviors in diverse treatments, including permanganate oxidation, solar/ultraviolet photolysis, advanced oxidation processes, advanced reduction process, and enzyme biological treatments. Besides, the different sources (i.e., terrestrial and aquatic, etc) of DOM, and operational circumstances (i.e., concentration and pH) fluctuate different transformation efficiency of micropollutants in water. However, so far, systematic explanations and summaries of relevant research and mechanism are rare. This paper reviewed the "trade-off" performances and the corresponding mechanisms of DOM in the elimination of micropollutants, and summarized the similarities and differences for the dual roles of DOM in each of the aforementioned treatments. Inhibition mechanisms typically include radical scavenging, UV attenuation, competition effect, enzyme inactivation, reaction between DOM and micropollutants, and intermediates reduction. Facilitation mechanisms include the generation of reactive species, complexation/stabilization, cross-coupling with pollutants, and electron shuttle. Moreover, electron-drawing groups (i.e., quinones, ketones functional groups) and electron-supplying groups (i.e., phenols) in the DOM are the main contributors to its trade-off effect.
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Affiliation(s)
- Xingyu Chen
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Jingquan Wang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Han Wu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Zhuoyu Zhu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Jianfei Zhou
- National Engineering Research Center of Clean Technology in Leather Industry, Sichuan University, Chengdu 610065, China.
| | - Hongguang Guo
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Industrial Technology Research Institute of Sichuan University, Yibin 644000, China.
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13
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Ma L, Worland R, Tran T, Anastasio C. Evaluation of Probes to Measure Oxidizing Organic Triplet Excited States in Aerosol Liquid Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6052-6062. [PMID: 37011016 DOI: 10.1021/acs.est.2c09672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Oxidizing triplet excited states of organic matter (3C*) drive numerous reactions in fog/cloud drops and aerosol liquid water (ALW). Quantifying oxidizing triplet concentrations in ALW is difficult because 3C* probe loss can be inhibited by the high levels of dissolved organic matter (DOM) and copper in particle water, leading to an underestimate of triplet concentrations. In addition, illuminated ALW contains high concentrations of singlet molecular oxygen (1O2*), which can interfere with 3C* probes. Our overarching goal is to find a triplet probe that has low inhibition by DOM and Cu(II) and low sensitivity to 1O2*. To this end, we tested 12 potential probes from a variety of compound classes. Some probes are strongly inhibited by DOM, while others react rapidly with 1O2*. One of the probe candidates, (phenylthiol)acetic acid (PTA), seems well suited for ALW conditions, with mild inhibition and fast rate constants with triplets, but it also has weaknesses, including a pH-dependent reactivity. We evaluated the performance of both PTA and syringol (SYR) as triplet probes in aqueous extracts of particulate matter. While PTA is less sensitive to inhibition than SYR, it results in lower triplet concentrations, possibly because it is less reactive with weakly oxidizing triplets.
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Affiliation(s)
- Lan Ma
- Department of Land, Air, and Water Resources, University of California, Davis, California 95616, United States
| | - Reed Worland
- Department of Land, Air, and Water Resources, University of California, Davis, California 95616, United States
| | - Theo Tran
- Department of Land, Air, and Water Resources, University of California, Davis, California 95616, United States
| | - Cort Anastasio
- Department of Land, Air, and Water Resources, University of California, Davis, California 95616, United States
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14
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Du R, Zhang Q, Leresche F, Zhong M, Chen P, Huang J, Deng S, Rosario-Ortiz FL, Yu G. The determination and prediction of the apparent reaction rates between excited triplet-state DOM and selected PPCPs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163117. [PMID: 37044337 DOI: 10.1016/j.scitotenv.2023.163117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 04/14/2023]
Abstract
To determine and predict the reaction rate between 3DOM* and PPCPs in various water bodies, this study defines a reaction rate coefficient ( [Formula: see text] ) to describe the reaction between 3DOM* and PPCPs. As the values also included the inhibition effect of DOM's antioxidant moieties, the calculation of [Formula: see text] is inconsistent with that of a bimolecular rate constant via the steady-state kinetic method. The [Formula: see text] values of 12 selected PPCPs were determined in two DOM solutions and ten DOM-containing water samples collected from typical surface water bodies in Beijing. The Pearson coefficients between nine predictors including the absorbance ratio (E2/E3), specific absorption coefficient at 254 nm (SUVA254), fluorescence index (FI), biological index (BIX), humification index (HIX), pH, total organic carbon (TOC), total fluorescence intensity (TFI) and TOC normalized TFI (TFI/TOC) and [Formula: see text] were examined. Correlation patterns for sulfonamides, β-blockers and diclofenac supported the electron transfer pathway, and was distinctly different from those appeared for FQs where quenching effect played a main part. TFI and TFI/TOC were recognized as the most useful surrogates in empirically predicting [Formula: see text] . For PPCPs that went through the electron transfer pathway, [Formula: see text] could be well fit to the Rehm-Weller model assuming a proportional relationship between TFI and △Get. For FQs, [Formula: see text] was found to linearly correlated with TFI/TOC. The [Formula: see text] values determined in this study enrich the database of PPCPs photolysis parameters, and the correlation analysis provides reference for forecasting PPCPs fate in the aquatic environment.
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Affiliation(s)
- Roujia Du
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Qianxin Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Frank Leresche
- Department of Civil, Environmental and Architectural Engineering, University of Colorado, Boulder, CO 80309, United States
| | - Mengmeng Zhong
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ping Chen
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Jun Huang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Shubo Deng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental and Architectural Engineering, University of Colorado, Boulder, CO 80309, United States
| | - Gang Yu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control, School of Environment, Tsinghua University, Beijing 100084, China; Advanced Interdisciplinary Institute of Environmental and Ecology, Beijing Normal University, Zhuhai 519000, China.
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15
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Wan D, Wang J, Chen T, Xiang W, Selvinsimpson S, Chen Y. Effect of disinfection on the photoreactivity of effluent organic matter and photodegradation of organic contaminants. WATER RESEARCH 2022; 219:118552. [PMID: 35550969 DOI: 10.1016/j.watres.2022.118552] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/28/2022] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
Chlorine, UV254, and ozone are three typical processes commonly used for wastewater disinfection, which could change the photoreactivity of dissolved organic matter (DOM) in effluents of wastewater treatment plants (WWTPs). The photoinduced reactive species (RS) from DOM, primarily including the excited triplet state of DOM (3DOM*), singlet oxygen (1O2), and hydroxyl radical (•OH), play important roles in the attenuation of contaminants. However, the effect of disinfection processes on the photosensitized degradation of contaminants is poorly understood. This paper presents the first evidence that 3DOM*, 1O2, and •OH interaction with three typical contaminants (diphenhydramine, cimetidine, and N,N-diethyl-m-toluamide (DEET)) was largely impacted by DOM after disinfection. The results of electron spin resonance (ESR) spectrometry and laser flash photolysis (LFP) experiments demonstrated that the chlorination increased the formation rate of 3DOM* and 1O2, while UV254 irradiation and ozonation decreased the formation rate of these RS. All these three disinfection processes promoted the photoproduction of •OH and increased the photodegradation rate constants (kobs) of DEET by 26-361%. The kobs of diphenhydramine, cimetidine, and DEET correlated positively with the formation rate of 3DOM*, 1O2, and •OH, respectively. The bimolecular reaction rate constant of 3DOM* with diphenhydramine increased by ∼41% after chlorination. These findings suggest that disinfection processes altered the photogeneration of RS from DOM, which significantly impacts the fate of trace pollutants in aquatic environments.
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Affiliation(s)
- Dong Wan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Jie Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Tong Chen
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | - Weiming Xiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China
| | | | - Yong Chen
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
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16
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Gao J, Nunes RF, O'Shea K, Saylor GL, Bu L, Kang YG, Duan X, Dionysiou DD, Luo S. UV/Sodium percarbonate for bisphenol A treatment in water: Impact of water quality parameters on the formation of reactive radicals. WATER RESEARCH 2022; 219:118457. [PMID: 35537369 DOI: 10.1016/j.watres.2022.118457] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 04/09/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Reported herein is an investigation of the impact of water quality parameters on the formation of carbonate radical anion (CO3•-) and hydroxyl radical (HO•) in UV/sodium percarbonate (UV/SPC) system versus in UV/hydrogen peroxide (UV/H2O2) system for bisphenol A (BPA) degradation in water. Pathways of CO3•- oxidation of BPA were proposed in this study based on the evolution of direct transformation products of BPA. Observed in this study, the degradation of BPA in the UV/SPC system was slower than that in the UV/H2O2 system in the secondary effluents collected from a local wastewater treatment plant due to the significant impact of coexisting constituents in the matrices on the former system. Single water quality parameter (e.g., solution pH, common anion, or natural organic matter) affected radical formations and BPA degradation in the UV/SPC system in a way similar to that in the UV/H2O2 system. Namely, the rise of solution pH decreased the steady state concentration of HO• resulting in a decrease in the observed pseudo first-order rate constant of BPA (kobs). Chloride anion and sulfate anion played a negligible role over the examined concentrations; nitrate anion slightly suppressed the reaction at the concentration of 20 mM; bicarbonate anion decreased the steady state concentrations of both CO3•- and HO• exerting significant inhibition on BPA degradation. Different extents of HO• scavenging were observed for different types of natural organic matter in the order of fulvic acid > mixed NOM > humic acid. However, the impact was generally less pronounced on BPA degradation in the UV/SPC system than that in the UV/H2O2 system due to the existence of CO3•-. The results of this study provide new insights into the mechanism of CO3•- based oxidation and new scientific information regarding the impact of water quality parameters on BPA degradation in the sytems of UV/SPC and UV/H2O2 from the aspect of reactive radical formation, which have reference value for UV/SPC application in wastewater treatment.
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Affiliation(s)
- Jiong Gao
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Roberta Frinhani Nunes
- Department of Chemical Engineering, Escola Politécnica, University of São Paulo, tr. 3, São Paulo 380, Brazil
| | - Kevin O'Shea
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Greg L Saylor
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Lingjun Bu
- Department of Water Engineering and Science, Hunan University, Hunan, Changsha 410082, China
| | - Yu-Gyeong Kang
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Xiaodi Duan
- Key Laboratory of Organic Compound Pollution Control Engineering (MOE), School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
| | - Shenglian Luo
- College of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, Jiangxi 330036, China
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17
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Mangalgiri K, Cheng Z, Cervantes S, Spencer S, Liu H. UV-based advanced oxidation of dissolved organic matter in reverse osmosis concentrate from a potable water reuse facility: A Parallel-Factor (PARAFAC) analysis approach. WATER RESEARCH 2021; 204:117585. [PMID: 34478993 DOI: 10.1016/j.watres.2021.117585] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/07/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
Disposal of reverse osmosis concentrate (ROC) from advanced water purification facilities is a challenge associated with the implementation of reverse osmosis-based treatment of municipal wastewater effluent for potable reuse. In particular, the dissolved organic matter (DOM) present in ROC diminishes the quality of the receiving water upon environmental disposal and affects the toxicity, fate, and transport of organic contaminants. This study investigates UV-based advanced oxidation processes (UV-AOPs) for treating DOM in ROC using a Parallel Factor Analysis (PARAFAC) approach. DOM composition and degradation were tested in UV-only and three UV-AOPs using hydrogen peroxide (H2O2), free chlorine (Cl2), and persulfate (S2O82-). The four-component PARAFAC model consisted of two terrestrial humic-like components (CUVH and CVisH), a wastewater/nutrient tracer component (CNuTr), and a protein-like (tyrosine-like) component (CPrTy). Based on the observed loss in the maximum fluorescence intensity of the components, DOM degradation was determined to be dependent on UV fluence, oxidant dose, and dilution factor of the ROC (i.e., bulk DOM concentration). CVisH was most the photolabile component in the UV-only system, followed by CNuTr, CPrTy, and CUVH, respectively. Furthermore, UV-H2O2 and UV-S2O82- displayed faster overall reaction kinetics compared to UV-Cl2. The degradation trends suggested that CNuTr and CPrTy consisted of chemical moieties that were susceptible to reactive oxygen species (HO•) but not reactive chlorine species; whereas, CVisH was sensitive to all reactive species generated in the three UV-AOPs. Compared to other components, CPrTy was recalcitrant in all treatment scenarios tested. Calculations using chemical probe-based analysis also confirmed these trends in the reactivity of DOM components. The outcomes of this study form a foundation for characterizing ROC reactivity in UV-AOP treatment technologies, to ultimately improve the sustainability of water reuse systems.
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Affiliation(s)
- Kiranmayi Mangalgiri
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Zhiwen Cheng
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States; School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
| | - Sheila Cervantes
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Samantha Spencer
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States
| | - Haizhou Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States; Program of Environmental Toxicology, University of California, Riverside, CA 92521, United States.
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18
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Zweigle J, Bugsel B, Schmitt M, Zwiener C. Electrochemical Oxidation of 6:2 Polyfluoroalkyl Phosphate Diester-Simulation of Transformation Pathways and Reaction Kinetics with Hydroxyl Radicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:11070-11079. [PMID: 34327989 DOI: 10.1021/acs.est.1c02106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Polyfluoroalkyl phosphate diesters (diPAPs) are widely used for paper and cardboard impregnation and discharged via waste streams from production processes and consumer products. To improve the knowledge about the environmental fate of diPAPs, electrochemical oxidation (EO) was used to characterize the transformation pathways and reaction kinetics. 6:2 diPAP was transformed electrochemically to perfluorocarboxylic acids (C5-C7 PFCAs) and two intermediates (6:2 fluorotelomer carboxylic acid, FTCA, and 6:2 fluorotelomer unsaturated carboxylic acid, FTUCA). EO of potential intermediates 6:2 monoPAP and 6:2 fluorotelomer alcohol (FTOH) showed similar transformation products but with different ratios. We show that 6:2 diPAP is initiated by OH radical (•OH) reactions, as evidenced by the measured steady-state concentrations of •OH with the probe molecule terephthalic acid, quenching experiments, and pH dependency of the reaction. PFHpA was the main product of 6:2 diPAP oxidation, and it was formed in a pseudo-first-order reaction for which a bimolecular rate constant was estimated to be k O • H , diPAP form PFHpA = 9.4(±1.4) × 107 M-1 s-1 by an initial rate approach. This can be utilized to estimate the environmental half-life of 6:2 diPAP for the reaction with •OH and the formation kinetics of persistent PFCAs.
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Affiliation(s)
- Jonathan Zweigle
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany
| | - Boris Bugsel
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany
| | - Markus Schmitt
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany
| | - Christian Zwiener
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, Tübingen 72076, Germany
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19
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Wan D, Wang J, Dionysiou DD, Kong Y, Yao W, Selvinsimpson S, Chen Y. Photogeneration of Reactive Species from Biochar-Derived Dissolved Black Carbon for the Degradation of Amine and Phenolic Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8866-8876. [PMID: 34165300 DOI: 10.1021/acs.est.1c01942] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Due to agricultural waste combustion and large-scale biochar application, biochar-derived dissolved black carbon (DBC) is largely released into surface waters. The photogeneration of reactive species (RS) from DBC plays an important role in organic pollutant degradation. However, the mechanistic interactions between RS and pollutants are poorly understood. Here, we investigated the formation of DBC triplet states (3DBC*), singlet oxygen (1O2), and hydroxyl radical (•OH) in straw biochar-derived DBC solutions and photodegradation of typical pharmaceuticals and personal care products (PPCPs). Laser flash photolysis and electron spin resonance spectrometry showed that DBC exhibited higher RS quantum yields than some well-studied dissolved organic matter. The RS caused rapid degradation of atenolol, diphenhydramine, and propylparaben, selected as target PPCPs in this study. The 3DBC* contributed primarily to the oxidation of selected PPCPs via one-electron-transfer interaction, with average reaction rate constants of 1.15 × 109, 1.41 × 109, and 0.51 × 109 M-1 s-1, respectively. •OH also participated in the degradation and accounted for approximately 2.7, 2.5, and 18.0% of the total removal of atenolol, diphenhydramine, and propylparaben, respectively. Moreover, the photodegradation products were identified using high-resolution mass spectrometry, which further confirmed the electron transfer and •OH oxidation mechanisms. These findings suggest that DBC from the combustion process of agricultural biomass can efficiently induce the photodegradation of organic pollutants under sunlight in aquatic environments.
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Affiliation(s)
- Dong Wan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Jie Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Dionysios D Dionysiou
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Yaqian Kong
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Wanying Yao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | | | - Yong Chen
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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20
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Schmitt M, Wack K, Glaser C, Wei R, Zwiener C. Separation of Photochemical and Non-Photochemical Diurnal In-Stream Attenuation of Micropollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8908-8917. [PMID: 34110816 DOI: 10.1021/acs.est.1c02116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
For a better process understanding of in-stream attenuation of trace organic contaminants (TrOCs), quantitative comparisons between field studies under different environmental conditions and controlled laboratory experiments are important to separate different processes. However, this is hampered by the challenge to transfer kinetics from the laboratory to different field conditions due to the lack of good quantitative measures to account for different boundary conditions. For phototransformation, in situ light conditions in a river are difficult to determine because light is reduced, for instance, by absorption, scattering on suspended particles, and shading effects. In this study, we present an approach to separate photochemical from non-photochemical diurnal in-stream attenuation based on rate constants relative to diclofenac, as a reference compound, to account for the difference in the in situ light conditions combined with laboratory experiments. 12 out of 45 detected target TrOCs showed a diurnal attenuation at a selected river stretch. A non-photochemical process, potentially biotransformation, was responsible for the diurnal attenuation of bisoprolol, metoprolol, O-desmethylvenlafaxine, tramadol, and venlafaxine. Attenuation of amisulpride, flufenamic acid, hydrochlorothiazide, naproxen, and xipamide can be quantitatively explained by phototransformation, partially for sotalol. Attenuation rate constants of hydrochlorothiazide at different field sites from this study and from published data range over 2 orders of magnitude. Differences can be quantitatively explained by different light exposures but not by water chemical parameters.
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Affiliation(s)
- Markus Schmitt
- Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
| | - Katja Wack
- Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
| | - Clarissa Glaser
- Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
| | - Ran Wei
- Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
| | - Christian Zwiener
- Center for Applied Geoscience, University of Tübingen, Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
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21
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Wan D, Wang H, Sharma VK, Selvinsimpson S, Dai H, Luo F, Wang C, Chen Y. Mechanistic Investigation of Enhanced Photoreactivity of Dissolved Organic Matter after Chlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8937-8946. [PMID: 34165279 DOI: 10.1021/acs.est.1c02704] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chlorine is commonly used in disinfection processes in wastewater treatment plants prior to discharge of the effluents into receiving waters. Effluent organic matter and humic substances constitute up to 90% of dissolved organic matter (DOM) in receiving water, which induces photogeneration of reactive species (RS) such as excited triplet state of DOM (3DOM*), singlet oxygen (1O2), and hydroxyl radical (•OH). The RS plays an important role in the attenuation of trace pollutants. However, the effect of chlorine disinfection on the photoreactivity of the DOM has remained unclear. Here, we investigated the physicochemical properties and subsequent RS variation after chlorination of DOM. Solid-state 13C cross-polarization/magic angle-spinning NMR and Fourier transform ion cyclotron resonance mass spectrometry verified that the aromaticity, electron-donating capacity (EDC), and average molecular weight of DOM decreased markedly after chlorination. It was found for the first time that the photoproduction of 3DOM*, 1O2, and •OH increased markedly after chlorination of DOM upon irradiation of simulated sunlight. The quantum yields of 3DOM*, 1O2, and •OH were positively correlated with E2/E3 (ratio of the absorbance at 254 to 365 nm) while negatively correlated with EDC before and after chlorination. These findings highlight the synergetic effect of chlorine disinfection on the photosensitization of DOM under irradiation of sunlight, which will promote the removal of trace pollutants in surface waters.
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Affiliation(s)
- Dong Wan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Haiyue Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Virender K Sharma
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, Texas 77843, United States
| | | | - Hongliang Dai
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Fan Luo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Chengjun Wang
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, P. R. China
| | - Yong Chen
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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22
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Felber T, Schaefer T, He L, Herrmann H. Aromatic Carbonyl and Nitro Compounds as Photosensitizers and Their Photophysical Properties in the Tropospheric Aqueous Phase. J Phys Chem A 2021; 125:5078-5095. [PMID: 34096724 DOI: 10.1021/acs.jpca.1c03503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Secondary organic aerosol formation in the atmospheric aqueous/particulate phase by photosensitized reactions is currently subject to uncertainties. To understand the impact of photosensitized reactions, photophysical and -chemical properties of photosensitizers, kinetic data, and reaction mechanisms of these processes are required. The photophysical properties of acetophenones, benzaldehydes, benzophenones, and naphthalenes were investigated in aqueous solution using laser flash excitation. Quantum yields of excited photosensitizers were determined giving values between 0.06-0.80 at 298 K and pH = 5. Molar absorption coefficients (εmax(3PS*) = (0.8-13) × 104 L mol-1 cm-1), decay rate constants in water (k1st = (9.4 ± 0.5) × 102 to (2.2 ± 0.1) × 105 s-1), and quenching rate constants with oxygen (kq(O2) = (1.7 ± 0.1-4.4 ± 0.4) × 109 L mol-1 s-1) of the excited triplet states were determined at 298 K and pH = 5. Photosensitized reactions of carboxylic acids and alkenes show second-order rate constants in the range of (37 ± 7.0-0.55 ± 0.1) × 104 and (27 ± 5.0-0.04 ± 0.01) × 108 L mol-1 s-1. The results show that different compound classes act differently as a photosensitizer and can be a sink for certain organic compounds in the atmospheric aqueous phase.
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Affiliation(s)
- Tamara Felber
- Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Thomas Schaefer
- Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Lin He
- Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hartmut Herrmann
- Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstrasse 15, 04318 Leipzig, Germany
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23
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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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24
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Remke SC, von Gunten U, Canonica S. Enhanced transformation of aquatic organic compounds by long-lived photooxidants (LLPO) produced from dissolved organic matter. WATER RESEARCH 2021; 190:116707. [PMID: 33373945 DOI: 10.1016/j.watres.2020.116707] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
Dissolved organic matter (DOM) plays a crucial role in the photochemical transformation of organic contaminants in natural aquatic systems. The present study focuses on the characterization of a specific effect previously observed for electron-rich phenols, consisting in an acceleration of the DOM-photosensitized transformation of target compounds at low concentrations (< 1 µM). This effect was hypothesized to be caused by DOM-derived "long-lived" photooxidants (LLPO). Pseudo-first-order rate constants for the transformation of several phenols, anilines, sulfonamide antibiotics and phenylureas photosensitized by Suwannee River fulvic acid were determined under steady-state irradiation using the UVA and visible wavelengths from a medium-pressure mercury lamp. A significant enhancement (by a factor of 2.4 - 16) of the first-order transformation rate constant of various electron-rich target compounds was observed for an initial concentration of 0.1 μM compared to 5 μM . This effect points to a relevant reactivity of these compounds with LLPO. For phenols and anilines the enhancement effect occurred only above certain standard one-electron oxidation potentials. From these data series the standard one-electron reduction potential of LLPO was estimated to be in the range of 1.0 - 1.3 V versus the standard hydrogen electrode. LLPO are proposed to mainly consist of phenoxyl radicals formed by photooxidation of electron-poor phenolic moieties of the DOM. The plausibility of this hypothesis was successfully tested by studying the photosensitized transformation kinetics of 3,4-dimethoxyphenol in aqueous solutions containing a model photosensitizer (2-acetonaphthone) and a model electron-poor phenol (4-cyanophenol) as DOM surrogates.
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Affiliation(s)
- Stephanie C Remke
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), GC A2 454, Station 18, CH-1015 Lausanne, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), GC A2 454, Station 18, CH-1015 Lausanne, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland.
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25
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Felber T, Schaefer T, Herrmann H. Five-Membered Heterocycles as Potential Photosensitizers in the Tropospheric Aqueous Phase: Photophysical Properties of Imidazole-2-carboxaldehyde, 2-Furaldehyde, and 2-Acetylfuran. J Phys Chem A 2020; 124:10029-10039. [PMID: 33202138 DOI: 10.1021/acs.jpca.0c07028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosensitized reactions of organic compounds in the atmospheric aqueous and particle phase might be potential sources for secondary organic aerosol (SOA) formation, addressed as aqueous SOA. However, data regarding the photophysical properties of photosensitizers, their kinetics, as well as reaction mechanisms of such processes in the aqueous/particle phase are scarce. The present study investigates the determination of the photophysical properties of imidazole-2-carboxaldehyde, 2-furaldehyde, and 2-acetylfuran as potential photosensitizers using laser flash excitation in aqueous solution. Quantum yields of the formation of the excited photosensitizers were obtained by a scavenging method with thiocyanate, resulting in values between 0.86 and 0.96 at 298 K and pH = 5. The time-resolved absorbance spectra of the excited photosensitizers were measured, and their molar attenuation coefficients were determined ranging between (0.30 and 1.4) × 104 L mol-1 cm-1 at their absorbance maxima (λmax = 335-440 nm). Additionally, the excited photosensitizers are quenched by water and molecular oxygen, resulting in quenching rate constants of k1st = (1.0 ± 0.2-1.8 ± 0.2) × 105 s-1 and kq(O2) = (2.1 ± 0.2-2.7 ± 0.2) × 109 L mol-1 s-1, respectively.
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Affiliation(s)
- Tamara Felber
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Thomas Schaefer
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hartmut Herrmann
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstrasse 15, 04318 Leipzig, Germany
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26
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Khare P, Machesky J, Soto R, He M, Presto AA, Gentner DR. Asphalt-related emissions are a major missing nontraditional source of secondary organic aerosol precursors. SCIENCE ADVANCES 2020; 6:6/36/eabb9785. [PMID: 32917599 PMCID: PMC7467703 DOI: 10.1126/sciadv.abb9785] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/21/2020] [Indexed: 05/14/2023]
Abstract
Asphalt-based materials are abundant and a major nontraditional source of reactive organic compounds in urban areas, but their emissions are essentially absent from inventories. At typical temperature and solar conditions simulating different life cycle stages (i.e., storage, paving, and use), common road and roofing asphalts produced complex mixtures of organic compounds, including hazardous pollutants. Chemically speciated emission factors using high-resolution mass spectrometry reveal considerable oxygen and reduced sulfur content and the predominance of aromatic (~30%) and intermediate/semivolatile organic compounds (~85%), which together produce high overall secondary organic aerosol (SOA) yields. Emissions rose markedly with moderate solar exposure (e.g., 300% for road asphalt) with greater SOA yields and sustained SOA production. On urban scales, annual estimates of asphalt-related SOA precursor emissions exceed those from motor vehicles and substantially increase existing estimates from noncombustion sources. Yet, their emissions and impacts will be concentrated during the hottest, sunniest periods with greater photochemical activity and SOA production.
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Affiliation(s)
- Peeyush Khare
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511, USA
| | - Jo Machesky
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511, USA
- Solutions for Energy, Air, Climate and Health (SEARCH), School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA
| | - Ricardo Soto
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511, USA
| | - Megan He
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511, USA
| | - Albert A Presto
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Drew R Gentner
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511, USA.
- Solutions for Energy, Air, Climate and Health (SEARCH), School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA
- Max Planck Institute for Chemistry, Mainz 55128, Germany
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27
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Ribeiro CP, Gamelas SR, Faustino MA, Gomes AT, Tomé JP, Almeida A, Lourenço LM. Unsymmetrical cationic porphyrin-cyclodextrin bioconjugates for photoinactivation of Escherichia coli. Photodiagnosis Photodyn Ther 2020; 31:101788. [DOI: 10.1016/j.pdpdt.2020.101788] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/06/2020] [Accepted: 04/20/2020] [Indexed: 01/23/2023]
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28
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Pan Y, Ruan X, Garg S, Waite TD, Lei Y, Yang X. Copper Inhibition of Triplet-Sensitized Phototransformation of Phenolic and Amine Contaminants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:9980-9989. [PMID: 32687340 DOI: 10.1021/acs.est.0c01693] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Excited triplet states of natural organic matter (3NOM*) are important reactive intermediates in phototransformation of organic contaminants in sunlit waters. The main goal of this study was to explore the influence of Cu on triplet-sensitized transformation rates of 20 selected phenolic and amine contaminants. Fourteen of the compounds examined exhibited a marked decrease in their 4-carboxybenzophenone (CBBP)-mediated phototransformation rate in the presence of trace amounts of Cu(II) (25-500 nM). Both mathematical modeling of these rate data and transient absorption spectroscopy measurements support the hypothesis that the decrease in the rate and extent of phototransformation of organic contaminants is due to the reduction of radical intermediates of the contaminants by photochemically formed Cu(I). The Cu-induced inhibition of oxidation of organic contaminants photosensitized by Suwannee River NOM (SRNOM) could also take place in the presence of nanomolar concentrations of Cu. The inhibitory effect of Cu on the oxidation rates of amine contaminants in SRNOM solutions was found to be significantly weaker compared to that in CBBP solutions, but little difference was observed on depletion of phenols. This behavior was attributed to the intrinsic inhibitory effect of the antioxidant moieties present in NOM on phototransformation of amine compounds, partially neutralizing the potential for further Cu inhibition.
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Affiliation(s)
- Yanheng Pan
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiaoxue Ruan
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Shikha Garg
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - T David Waite
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yu Lei
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
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29
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McKay G. Emerging investigator series: critical review of photophysical models for the optical and photochemical properties of dissolved organic matter. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:1139-1165. [PMID: 32270849 DOI: 10.1039/d0em00056f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Optical measurements (absorbance and fluorescence) are widely used to track dissolved organic matter (DOM) quantity and quality in natural and engineered systems. Despite many decades of research on the optical properties of DOM, there is a lack of understanding with regards to the underlying photophysical model that is the basis for these optical properties. This review both summarizes advances to date on the photophysical properties of DOM and seeks to critically evaluate the photophysical models for DOM optical properties. Recent studies have refined the quantitative understanding of DOM photophysical properties such as excited state lifetimes and energies, rates of different photophysical processes, and quantum yields. Considering fundamental models, more clarity is needed on whether DOM photophysical processes are due to a superposition of non-interacting components (superposition model), or whether a portion of optical signals can be ascribed to electronically interacting moieties, for example in the form of electron donor-acceptor complexes (charge transfer model). Multiple studies over more than two decades have provided evidence for the charge transfer model. Questions have been raised, however, about the broad applicability of the charge transfer model. The charge transfer and superposition model are critically reviewed in light of this current research. Recommendations are given for future studies to help clarify the accuracy of these competing photophysical models.
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Affiliation(s)
- Garrett McKay
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA.
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30
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Zhou Q, Zhang X, Zhou C. Transformation of amino acid tyrosine in chromophoric organic matter solutions: Generation of peroxide and change of bioavailability. CHEMOSPHERE 2020; 245:125662. [PMID: 31864059 DOI: 10.1016/j.chemosphere.2019.125662] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/07/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Studying the photochemical transformation mechanism of dissolved free amino acids (DFAA) in chromophoric dissolved organic matter (CDOM) solution facilitates the understanding of DFAA's environmental fate and bioavailability change upon solar irradiation in natural surface waters. Tyrosine oxidation product (Tyr-OH) was synthesized to quantify the primary transformation product (tyrosine peroxide, Tyr-OOH) in CDOM solution. Both reactions between superoxide radical anion (O2-) and tyrosine radical (Tyr) and between singlet oxygen (1O2) and tyrosine (Tyr) yield Tyr-OOH, which is subsequently transformed into Tyr-OH. The reaction between O2- and Tyr not only generated Tyr-OOH but also caused the regeneration of Tyr. O2- and 1O2 contributed 30-44% to Tyr's transformation in CDOM solutions at pH 8.0, in which 1O2 oxidation accounted for 6-11%. The contribution of O2- to Tyr's phototransformation process was the difference between the total contribution of O2- and 1O2 and the individual contribution of 1O2. Compared with the fast assimilation of Tyr, Tyr-OH was stable in natural water under dark incubation, indicating that phototransformation decreased the bioavailability of Tyr.
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Affiliation(s)
- Qing Zhou
- Department of Environmental Science, School of Resources and Environmental Science, Wuhan University, Wuhan, 430079, PR China.
| | - Xu Zhang
- Department of Environmental Science, School of Resources and Environmental Science, Wuhan University, Wuhan, 430079, PR China.
| | - Chi Zhou
- Hubei Water Resources Research Institute, Hubei Water Resources and Hydropower Science and Technology Promotion Center Wuhan, 430070, PR China.
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31
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A Critical View of the Application of the APEX Software (Aqueous Photochemistry of Environmentally-Occurring Xenobiotics) to Predict Photoreaction Kinetics in Surface Freshwaters. Molecules 2019; 25:molecules25010009. [PMID: 31861417 PMCID: PMC7017383 DOI: 10.3390/molecules25010009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/09/2019] [Accepted: 12/11/2019] [Indexed: 02/01/2023] Open
Abstract
The APEX (aqueous photochemistry of environmentally occurring xenobiotics) software computes the phototransformation kinetics of compounds that occur in sunlit surface waters. It is free software based on Octave, and was originally released in 2014. Since then, APEX has proven to be a remarkably flexible platform, allowing for the addressing of several environmental problems. However, considering APEX as a stand-alone software is not conducive to exploiting its full potentialities. Rather, it is part of a whole ecosystem that encompasses both the software and the laboratory protocols that allow for the measurement of substrate photoreactivity parameters. Coherently with this viewpoint, the present paper shows both how to use APEX, and how to experimentally derive or approximately assess the needed input data. Attention is also given to some issues that might provide obstacles to users, including the extension of APEX beyond the simple systems for which it was initially conceived. In particular, we show how to use APEX to deal with compounds that undergo acid–base equilibria, and with the photochemistry of systems such as stratified lakes, lakes undergoing evaporation, and rivers. Hopefully, this work will provide a reference for the smooth use of one of the most powerful instruments for the modeling of photochemical processes in freshwater environments. All authors have read and agreed to the published version of the manuscript.
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32
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Carena L, Puscasu CG, Comis S, Sarakha M, Vione D. Environmental photodegradation of emerging contaminants: A re-examination of the importance of triplet-sensitised processes, based on the use of 4-carboxybenzophenone as proxy for the chromophoric dissolved organic matter. CHEMOSPHERE 2019; 237:124476. [PMID: 31404736 DOI: 10.1016/j.chemosphere.2019.124476] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/24/2019] [Accepted: 07/27/2019] [Indexed: 06/10/2023]
Abstract
The photoreactions sensitised by the excited triplet states of chromophoric dissolved organic matter (3CDOM*) are very important in the photochemical attenuation of emerging contaminants in natural waters. Until quite recently, anthraquinone-2-sulphonate (AQ2S) was the only available CDOM proxy molecule to estimate the contaminant reaction kinetics with 3CDOM*, under steady-state irradiation conditions. Unfortunately, the AQ2S triplet state (3AQ2S*) is considerably more reactive than average 3CDOM*. We have recently developed an alternative protocol based on 4-carboxybenzophenone (CBBP), the triplet state of which (3CBBP*) is less reactive compared to 3AQ2S*. Here we show that in the case of ibuprofen (IBP), paracetamol (APAP) and clofibric acid (CLO), the reaction rate constants with 3CBBP* are more reasonable as 3CDOM* reactivity estimates than those obtained by using AQ2S. In contrast, similar rate constants are measured for the reaction of atrazine (ATZ) with either 3AQ2S* or 3CBBP*. Moreover, the reactivity of ATZ with both 3AQ2S* and 3CBBP* is very similar to that with 3CDOM*, available through a literature estimate. The possibility to validate the ATZ-3CBBP* reactivity estimate against the 3CDOM* data, and to accurately predict the reported IBP and CLO field lifetime, support the suitability of CBBP as CDOM proxy. The replacement of AQ2S with CBBP as proxy molecule does not reverse the qualitative prediction, according to which 3CDOM* would be the main process involved in the photodegradation of the studied contaminants in waters with high dissolved organic carbon (DOC). However, the CBBP-based data prompt for an important reconsideration of the estimated lifetimes at high DOC.
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Affiliation(s)
- Luca Carena
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125, Torino, Italy
| | - Cezara G Puscasu
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125, Torino, Italy
| | - Silvia Comis
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125, Torino, Italy
| | - Mohamed Sarakha
- Institut de Chimie de Clermont-Ferrand, Clermont Université, Université Blaise Pascal, F-63177, Aubière, France
| | - Davide Vione
- Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125, Torino, Italy.
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33
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Ossola R, Schmitt M, Erickson PR, McNeill K. Furan Carboxamides as Model Compounds To Study the Competition between Two Modes of Indirect Photochemistry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9594-9603. [PMID: 31335132 DOI: 10.1021/acs.est.9b02895] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Singlet oxygen (1O2) and triplet chromophoric dissolved organic matter (3CDOM*) are photochemically produced reactive intermediates responsible for the photodegradation of several micropollutants in the sunlit surface waters. However, elucidating the mechanism of reactions involving both 1O2 and 3CDOM* can be complicated by the deeply interconnected nature of these two reactive species. In this work, we synthesized a series of model compounds inspired by the chemical structure of fenfuram, a fungicide used in the 1980s, and used them to investigate structure-reactivity relationships in photodegradation reactions involving 1O2 and 3CDOM*. A combination of steady-state and time-resolved approaches was employed to successfully predict the extent of 1O2-induced degradation. Conversely, the prediction of triplet-induced reactivity was complicated by the presence of repair mechanisms whose extent and relative importance were difficult to predict. The results of our work indicate that bimolecular rate constants measured via time-resolved techniques alone are not sufficient to accurately predict environmental half-lives, as intrinsic differences in the reaction mechanism can amplify the importance of secondary degradation pathways.
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Affiliation(s)
- Rachele Ossola
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Markus Schmitt
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Paul R Erickson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
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34
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Schmitt M, Moor KJ, Erickson PR, McNeill K. Sorbic Acid as a Triplet Probe: Reactivity of Oxidizing Triplets in Dissolved Organic Matter by Direct Observation of Aromatic Amine Oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8087-8096. [PMID: 31269391 DOI: 10.1021/acs.est.9b01789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sorbic acid (2,4-hexadienoic acid; HDA) isomerization is frequently used to probe triplet-state dissolved organic matter (3CDOM*) reactivity, but there remain open questions about the reaction kinetics of 3CDOM* with HDA due to the difficulties of directly measuring 3CDOM* quenching rate constants. Using our recently developed approach based on observing the radical cation of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) formed through oxidation of TMPD by 3CDOM*, we studied 3CDOM* quenching kinetics with HDA monitored via transient absorption spectroscopy. A competition kinetics-based approach utilizing formation yields of TMPD•+ was developed, validated with model sensitizers, and used to determine bimolecular rate constants between 3CDOM* oxidants and HDA for diverse DOM isolates and natural waters samples, yielding values in the range of (2.4-7.7) × 108 M-1 s-1. The unquenchable fraction of TMPD-oxidizing triplets showed that, on average, 41% of 3CDOM* oxidants cannot be quenched by HDA. Conversely, cycloheptatriene quenched nearly all TMPD•+-forming triplets in CDOM, suggesting that most 3CDOM* oxidants possess energies greater than 150 kJ mol-1. Comparing results with our companion study, we found slight, but noticeable differences in the 3CDOM* quenching rate constants by HDA and unquenchable triplet fractions determined by oxidation of TMPD and energy transfer to O2 (1O2 formation) methods.
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Affiliation(s)
- Markus Schmitt
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kyle J Moor
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Paul R Erickson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
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Moor KJ, Schmitt M, Erickson PR, McNeill K. Sorbic Acid as a Triplet Probe: Triplet Energy and Reactivity with Triplet-State Dissolved Organic Matter via 1O 2 Phosphorescence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8078-8086. [PMID: 31268694 DOI: 10.1021/acs.est.9b01787] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sorbic acid (2,4-hexadienoic acid; HDA) is commonly used as a probe and quencher for triplet-excited chromophoric dissolved organic matter (3CDOM*), an important transient species in natural waters, yet much remains unknown about its reactivity with 3CDOM* and its triplet energy. To better understand the quenching behavior of HDA, we measured HDA quenching rate constants for various humic substance isolates and whole waters with singlet oxygen (1O2) phosphorescence and determined the triplet energy of HDA. Low-temperature phosphorescence measurements determined the triplet energy of HDA to be 217 kJ mol-1, whereas a complementary method based on triplet quenching kinetics found a triplet energy of 184 ± 7 kJ mol-1. Time-resolved 1O2 phosphorescence measurements yielded different HDA quenching rate constants depending on the fitting method. Using an approach that considered the reactivity of the entire triplet pool produced values of (∼1-10) × 108 M-1 s-1, while an approach that considered only the reactivity of the high-energy triplets output higher rate constants ((∼7-30) × 108 M-1 s-1). In addition, the model based on high-energy triplet reactivity found that ∼30-60% of 3CDOM* is not quenched by HDA. Findings from this study provide a more comprehensive view on the use of HDA as a probe for 3CDOM*.
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Affiliation(s)
- Kyle J Moor
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Markus Schmitt
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Paul R Erickson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
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O'Connor M, Helal SR, Latch DE, Arnold WA. Quantifying photo-production of triplet excited states and singlet oxygen from effluent organic matter. WATER RESEARCH 2019; 156:23-33. [PMID: 30903967 DOI: 10.1016/j.watres.2019.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/22/2019] [Accepted: 03/08/2019] [Indexed: 05/21/2023]
Abstract
The organic matter present in wastewater effluents (EfOM), is likely to have different properties than the organic matter present in the receiving water. The properties of EfOM will affect the fate of contaminants of emerging concern because EfOM is a source of photochemically produced reactive intermediates (PPRIs) capable of transforming contaminants. Effluent water samples were taken seasonally from sixteen wastewater treatment plants in Minnesota and two effluent dominated rivers in California and Arizona. Samples (n = 94) were tested for water chemistry, light absorption characteristics, and excited state triplet organic matter (3EfOM∗) and singlet oxygen (1O2) production. Based on analysis of spectral parameters, EfOM had higher molecular weight and lower aromatic content than organic matter present in stormwaters from Minnesota, which are representative of human-impacted natural organic matter (NOM) containing waters. The second order rate constant for the reaction of the 3EfOM∗ probe 2,4,6-trimethylephenol (kT,TMP) for the effluents was 7.79 (±3.03) × 108 M-1s-1, and this value was used to calculate apparent quantum yields for 3EfOM∗ production, which ranged from 0.006 to 0.114. The quantum yield for the production of singlet oxygen ranged from 0.007 to 0.064. Processes in the wastewater treatment train, season, and water chemistry parameters did not serve as predictors of 3EfOM∗ or 1O2 production. Among the parameters measured, Spearman rank correlations were strongest between quantum yields of 1O2 and 3EfOM∗ and E2/E3 (absorption at 250 nm/absorption at 365 nm). This relationship, however, is weaker than that previously observed for NOM. The efficiency of 1O2 production from 3EfOM∗ was 54%. Results indicate that 2,4,6-trimethylphenol samples nearly all of the triplets in EfOM that have sufficient energy to produce 1O2, which may not be the case for NOM.
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Affiliation(s)
- Meghan O'Connor
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota-Twin Cities, 500 Pillsbury Dr. SE, Minneapolis, MN, 55455, USA
| | - Samantha R Helal
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota-Twin Cities, 500 Pillsbury Dr. SE, Minneapolis, MN, 55455, USA
| | - Douglas E Latch
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA, 98122, USA
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota-Twin Cities, 500 Pillsbury Dr. SE, Minneapolis, MN, 55455, USA.
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Leresche F, McKay G, Kurtz T, von Gunten U, Canonica S, Rosario-Ortiz FL. Effects of Ozone on the Photochemical and Photophysical Properties of Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5622-5632. [PMID: 31022348 DOI: 10.1021/acs.est.8b06410] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study focused on the effects of ozonation on the photochemical and photophysical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in DOM absorbance was observed in parallel with an increase in singlet oxygen (1O2) and fluorescence quantum yields (Φ1O2 and ΦF). The increase in Φ1O2 was attributed to the formation of quinone-like moieties during ozonation of the phenolic moieties of DOM, while the increase in ΦF can be explained by a significant decrease in the internal conversion rate of the first excited singlet state of the DOM (1DOM*). It is a consequence of an increase in the average energy of the first electronic transition (S1 → S0) that was assessed using the wavelength of maximum fluorescence emission (λF,max). Furthermore, ozonation did not affect the ratio of the apparent steady-state concentrations of excited triplet DOM (3DOM*) and 1O2, indicating that ozonation does not affect the efficiency of 1O2 production from 3DOM*. The consequences of these changes for the phototransformation rates of micropollutants in surface waters were examined using photochemical model calculations. The decrease in DOM absorbance caused by ozonation leads to an enhancement of direct photolysis rates due to the increased transparency of the water. Rates of indirect photooxidation induced by 1O2 and 3DOM* slightly decrease after ozonation.
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Affiliation(s)
- Frank Leresche
- Department of Civil, Environmental and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Garrett McKay
- Department of Civil, Environmental and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Tyler Kurtz
- Department of Civil, Environmental and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Überlandstrasse 133 , CH-8600 Dübendorf , Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC) , Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Überlandstrasse 133 , CH-8600 Dübendorf , Switzerland
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
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Pflug NC, Schmitt M, McNeill K. Development of N-Cyclopropylanilines to Probe the Oxidative Properties of Triplet-State Photosensitizers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4813-4822. [PMID: 30912935 DOI: 10.1021/acs.est.9b00416] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Anilines have been shown to be especially susceptible to single-electron oxidation by excited triplet-state photosensitizers (3sens*), and thus, are good potential candidates to probe the oxidative properties of triplet-state chromophoric dissolved organic matter (3CDOM*). However, steady-state experiments tend to underestimate their rate of oxidation by 3CDOM* due to radical cation quenching (i.e., aniline•+ → aniline) by antioxidant moieties present in DOM. We envisioned the potential utility of N-cyclopropylaniline (CPA) to overcome this limitation, as it is known to undergo spontaneous, irreversible cyclopropyl ring-opening after an initial single-electron oxidation. To test this, first a set of CPA analogs was synthesized and then paired with a model sensitizer and antioxidant, or various DOM isolates, to examine their reactivity and susceptibility to antioxidant quenching during steady-state photolysis experiments. Next, time-resolved measurements of CPA and CPA analog oxidation were obtained by laser flash photolysis through direct observation of 3sens* and radical cations of CPA and CPA analogs. Finally, CPA photolysis products were isolated by semi-preparative high-performance liquid chromatography and identified by nuclear magnetic resonance spectroscopy. Outcomes of this work, including oxidation bimolecular rate constants of CPA and CPA analogs (∼9 × 108 to 4 × 109 M-1 s-1), radical cation lifetimes of CPA and its analogs (140-580 ns), and identified ring-opened products, support the usefulness of cyclopropylanilines as single-electron transfer probes in photosensitized aqueous solutions.
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Affiliation(s)
- Nicholas C Pflug
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , 8092 Zurich Switzerland
| | - Markus Schmitt
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , 8092 Zurich Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , 8092 Zurich Switzerland
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Zhao J, Zhang X, Zhu R, Su T, Phillips DL. Photophysical Properties Controlled by Substituents with Lone-Pair Electrons at the Ortho- or Para-Positions of Fluoroquinolone Antibiotics. J Phys Chem B 2019; 123:3156-3162. [PMID: 30900898 DOI: 10.1021/acs.jpcb.8b10859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ortho- or para-substituents of NH2 or N-alkyl-containing lone-pair electrons were found to change the energy levels and transition configurations of the highest occupied molecular orbital for some fluoroquinolone-based antibiotics (FQs) and can significantly influence the electronic structure, intermolecular hydrogen bonding, internal conversion, and fluorescence and intersystem crossing efficiencies of FQs in acetonitrile or aqueous solution after photoexcitation. These findings provide new insights that can help in the molecular design strategies to regulate the photophysical properties of photosensitive medicines, photodynamic therapy reagents, and energy conversion materials that contain similar aromatic carbonyl structures.
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Affiliation(s)
- Jianfeng Zhao
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong 11111 , P. R. China
| | - Xiting Zhang
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong 11111 , P. R. China
| | - Ruixue Zhu
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong 11111 , P. R. China.,School of Physical Science and Technology , Shanghai Tech University , Shanghai 201210 , P. R. China
| | - Tao Su
- Department of Molten Salt Chemistry and Engineering, Shanghai Institute of Applied Physics , Chinese Academy of Sciences , 2019, Jia Luo Road , Jiading District, Shanghai 201800 , P. R. China
| | - David Lee Phillips
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong 11111 , P. R. China
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Wang J, Chen J, Qiao X, Wang Y, Cai X, Zhou C, Zhang Y, Ding G. DOM from mariculture ponds exhibits higher reactivity on photodegradation of sulfonamide antibiotics than from offshore seawaters. WATER RESEARCH 2018; 144:365-372. [PMID: 30053627 DOI: 10.1016/j.watres.2018.07.043] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 07/14/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
Mariculture activities and river inputs lead to coastal seawaters with DOM levels that are comparable to or even higher than those in terrestrial water bodies. However, effects of seawater DOM, and especially of DOM occurring in areas impacted by mariculture, on photodegradation of organic micropollutants, are largely unknown. In this study, simulated sunlight irradiation experiments were performed to probe the effects of DOM extracted from mariculture impacted seawaters and from offshore areas, on photodegradation of three sulfonamide antibiotics (SAs). Results show that the SAs are transformed mainly by indirect photodegradation induced by triplet excited DOM (3DOM*). Compared with DOM from the more pristine coastal waters, the DOM from mariculture impacted areas undergoes less photobleaching, contains higher percentage of humic-like materials and higher proportions of aromatic and carbonyl structures. Thus, the DOM from mariculture areas exhibits higher rates of light absorption, higher formation quantum yields of 3DOM*, higher 3DOM* steady-state concentrations and higher reactivity on photodegradation of the SAs. Photochemistry of the seawater DOM is different from that reported for freshwater lake DOM. This study highlights the importance of probing the effects of DOM from coastal seawaters on photodegradation of organic micropollutants since coastal seawaters are sinks of many aquatic pollutants.
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Affiliation(s)
- Jieqiong Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China.
| | - Xianliang Qiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Yan Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Xiyun Cai
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Chengzhi Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China
| | - Yaoling Zhang
- Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China
| | - Guanghui Ding
- College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
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Erickson PR, Moor KJ, Werner JJ, Latch DE, Arnold WA, McNeill K. Singlet Oxygen Phosphorescence as a Probe for Triplet-State Dissolved Organic Matter Reactivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9170-9178. [PMID: 30024152 DOI: 10.1021/acs.est.8b02379] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Triplet-state chromophoric dissolved organic matter (3CDOM*) plays an important role in aquatic photochemistry, yet much remains unknown about the reactivity of these intermediates. To better understand the kinetic behavior and reactivity of 3CDOM*, we have developed an indirect observation method based on monitoring time-resolved singlet oxygen (1O2) phosphorescence kinetics. The underpinning principle of our approach relies on the fact that O2 quenches almost all triplets with near diffusion limited rate constants, resulting in the formation of 1O2, which is kinetically linked to the precursors. A kinetic model relating 1O2 phosphorescence kinetics to triplet excited states produced from isolated humic substances and in whole natural-water samples (hereafter referred to as 3CDOM*) was developed and used to determine rate constants governing 3CDOM* natural lifetimes and quenching by oxygen and 2,4,6-trimethylphenol (TMP), a common triplet probe molecule. 3CDOM* was found to exhibit smaller O2 and TMP quenching rate constants, ∼9 × 108 and ∼8 × 108 M-1 s-1, respectively, compared with model sensitizers, such as aromatic ketones. Findings from this report shed light on the fundamental photochemical properties of CDOM in organic matter isolates and whole waters and will help refine photochemical models to more accurately predict pollutant fate in the environment.
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Affiliation(s)
- Paul R Erickson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Kyle J Moor
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Jeffrey J Werner
- Chemistry Department , SUNY , Cortland , New York 13045 , United States
| | - Douglas E Latch
- Department of Chemistry , Seattle University , Seattle , Washington 98122 , United States
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science , ETH Zurich , 8092 Zurich , Switzerland
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McKay G, Korak JA, Rosario-Ortiz FL. Temperature Dependence of Dissolved Organic Matter Fluorescence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9022-9032. [PMID: 30028602 DOI: 10.1021/acs.est.8b00643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The temperature dependence of organic matter fluorescence apparent quantum yields (Φf) was measured for a diverse set of organic matter isolates (i.e., marine aquatic, microbial aquatic, terrestrial aquatic, and soil) in aqueous solution and for whole water samples to determine apparent activation energies ( Ea) for radiationless decay processes of the excited singlet state. Ea was calculated from temperature dependent Φf data obtained by steady-state methods using a simplified photophysical model and the Arrhenius equation. All aquatic-derived isolates, all whole water samples, and one soil-derived fulvic acid isolate exhibited temperature dependent Φf values, with Ea ranging from 5.4 to 8.4 kJ mol-1 at an excitation wavelength of 350 nm. Conversely, soil humic acid isolates exhibited little or no temperature dependence in Φf. Ea varied with excitation wavelength in most cases, typically exhibiting a decrease between 350 and 500 nm. The narrow range of Ea values observed for these samples when compared to literature Ea values for model fluorophores (∼5-30 kJ mol-1) points to a similar photophysical mechanism for singlet excited states nonradiative inactivation across organic matter isolates of diverse source and character. In addition, this approach to temperature dependent fluorescence analysis provides a fundamental, physical basis, in contrast to existing empirical relationships, for correcting online fluorescence sensors for temperature effects.
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Affiliation(s)
- Garrett McKay
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Julie A Korak
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado , Boulder , Colorado 80309 , United States
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