1
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Zeng Y, Zhang M, Fu Q, Chen N, Wang Y, Zhou D, Fang G. Formation of reactive intermediates in paddy water from different temperature zones for the promotion of abiotic ammonification. WATER RESEARCH 2024; 255:121523. [PMID: 38554632 DOI: 10.1016/j.watres.2024.121523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/15/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024]
Abstract
The paddy field is a hot area of biogeochemical process. The paddy water has a large capacity in photo-generation of reactive intermediates (RIs) due to abundant photosensitive dissolved organic matter (DOM), which is influenced by the spatial heterogeneity of paddy soils but rarely been explored. Our work presents the first investigation of the role of soil properties on photochemistry in paddy water. Soil organic matter (SOM), determined by the temperature, was the dominant factor for the photo-generation of RIs in paddy water of main rice producing areas. The RI concentrations generated with abundant SOM from cool regions are 0.05-8.71 times higher than those for the warm regions in China. The humic-like substance and aromatic-like compounds of DOM plays an essential role in RIs generation, which is abundant in paddy soils rich in SOM from Chinese cool regions. In addition, RIs can efficiently accelerate the photo-ammonification of urea and free amino acids by 15.2 %-164 %, leading to 0.13-0.17 mmol/L/d photo-produced ammonium after fertilization, which is preferentially absorbed by rice. The findings of this study will extend our knowledge of the geochemistry of global paddy field ecosystem. The potential role of RIs in nitrogen cycle should be highlighted in the agroecosystem.
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Affiliation(s)
- Yu Zeng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Mingyang Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qinglong Fu
- School of Environmental Studies, China University of Geoscience, Wuhan 430074, PR China
| | - Ning Chen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Yujun Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Guodong Fang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
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2
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Zhou C, Wu B, Zheng X, Chen B, Chu C. Wavelength-dependent direct and indirect photochemical transformations of organic pollutants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170414. [PMID: 38272084 DOI: 10.1016/j.scitotenv.2024.170414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 01/21/2024] [Accepted: 01/22/2024] [Indexed: 01/27/2024]
Abstract
Sunlight-induced photochemical transformations greatly affect the persistence of organic pollutants in natural environment. Whereas sunlight intensity is well-known to affect pollutant phototransformation rates, the reliance of pollutant phototransformation kinetics on sunlight spectrum remains poorly understood, which may greatly vary under different spatial-temporal, water matrix, and climatic conditions. Here, we systematically assessed the wavelength-dependent direct and indirect phototransformations of 12 organic pollutants. Their phototransformation rates dramatically decreased with light wavelength increasing from 375 to 632 nm, with direct photolysis displaying higher wavelength-dependence than indirect photolysis. Remarkably, UV light dominated both direct (90.4-99.5 %) and indirect (64.6-98.7 %) photochemical transformations of all investigated organic pollutants, despite its minor portion in sunlight spectrum (e.g., 6.5 % on March 20 at the equator). Based on wavelength-dependent rate constant spectrum, the predicted phototransformation rate of chloramphenicol (4.5 ± 0.7 × 10-4 s-1) agreed well with the observed rate under outdoor sunlight irradiation (4.3 ± 0.0 × 10-4 s-1), and there is no significant difference between the predicted rate and the observed rate (p-value = 0.132). Moreover, rate constant and quantum yield coefficient (QYC) spectrum could be applied for facilely investigate the influence of spectral changes on the phototransformation of pollutants under varying spatial-temporal (e.g., season, latitude) and climatic conditions (e.g., cloud cover). Our study highlights the wavelength-dependence of both direct and indirect phototransformation of pollutants, and the UV part of natural sunlight plays a decisive role in the phototransformation of pollutants.
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Affiliation(s)
- Chong Zhou
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Binbin Wu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Xiaoshan Zheng
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Chiheng Chu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
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3
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Cheng K, Zhang L, McKay G. Evaluating the Microheterogeneous Distribution of Photochemically Generated Singlet Oxygen Using Furfuryl Amine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7568-7577. [PMID: 37130219 PMCID: PMC10853930 DOI: 10.1021/acs.est.3c01726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 05/04/2023]
Abstract
Singlet oxygen (1O2) is an important reactive species in natural waters produced during photolysis of dissolved organic matter (DOM). Prior studies have demonstrated that 1O2 exhibits a microheterogeneous distribution, with [1O2] in the interior of DOM macromolecules ∼30 to 1000-fold greater than in bulk solution. The [1O2] profile for DOM-containing solutions has been determined mainly by the use of hydrophobic probes, which are not commercially available. In this study, we employed a dual-probe method combining the widely used hydrophilic 1O2 probe furfuryl alcohol (FFA) and its structural analogue furfuryl amine (FFAm). FFAm exists mainly as a cation at pH <9 and was therefore hypothesized to have an enhanced local concentration in the near-DOM phase, whereas FFA will be distributed homogeneously. The probe pair was used to quantify apparent [1O2] in DOM samples from different isolation procedures (humic acid, fulvic acid, reverse osmosis) and diverse origins (aquatic and terrestrial) as a function of pH and ionic strength, and all samples studied exhibited enhanced reactivity of FFAm relative to FFA, especially at pH 7 and 8. To quantify the spatial distribution of [1O2], we combined electrostatic models with Latch and McNeill's three-phase distribution model. Modeling results for Suwannee River humic acid (SRHA) yield a surface [1O2] of ∼60 pM, which is ∼96-fold higher than the aqueous-phase [1O2] measured with FFA. This value is in agreement with prior reports that determined 1-3 orders of magnitude higher [1O2] in the DOM phase compared to bulk solution. Overall, this work expands the knowledge base of DOM microheterogeneous photochemistry by showing that diverse DOM isolates exhibit this phenomenon. In addition, the dual-probe approach and electrostatic modeling offer a new way to gain mechanistic insight into the spatial distribution of 1O2 and potentially other photochemically produced reactive intermediates.
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Affiliation(s)
- Kai Cheng
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, 3131 TAMU, College Station, Texas 77845, United States
| | - Lizhong Zhang
- Department
of Physics, University of California, Santa
Barbara, Santa
Barbara, California 93106, United States
| | - Garrett McKay
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, 3131 TAMU, College Station, Texas 77845, United States
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4
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Wu B, Liu T, Wang Y, Zhao G, Chen B, Chu C. High Sample Throughput LED Reactor for Facile Characterization of the Quantum Yield Spectrum of Photochemically Produced Reactive Intermediates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16204-16214. [PMID: 34553927 DOI: 10.1021/acs.est.1c04608] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Photochemically produced reactive intermediates (PPRIs) by natural photosensitizers such as chromophoric dissolved organic matter (CDOM) play numerous key roles in aquatic biogeochemical processes. PPRI productions rely on both the intensity and the spectrum of incident sunlight. While the impacts of sunlight intensity on PPRI productions are well-studied, there remains insufficient understanding of the spectrum-dependence of PPRI productions. Here we designed a high sample throughput reactor equipped with monochromatic LED lights for systematic assessments of wavelength-dependent productions of four important PPRI species, i.e., triplet-state excited CDOM (3CDOM*), singlet oxygen (1O2), hydrogen peroxide (H2O2), and hydroxyl radical (•OH), in CDOM solutions. The quantum yields of PPRIs followed the order: 3CDOM* > 1O2 ≫ H2O2 > •OH. Moreover, PPRI quantum yields decreased with the light wavelength increasing from 375 to 490 nm and sharply decreased to zero above 490 nm, while the shapes of quantum yield spectra differed among PPRI species. Simulations on PPRI productions under varying season, latitude, altitude, and cloud cover conditions show that the sunlight spectrum plays a role as equally important as intensity in determining PPRI productions and PPRI-mediated transformations of aquatic nutrients and micropollutants. Therefore, incorporating the spectrum dependence of PPRI productions will advance our understandings of PPRI-driven biogeochemical processes and pollutant dynamics under varying spatial-temporal and climatic conditions. Regarding this, the high sample throughput LED reactor sheds light on a new approach for the facile characterization of PPRI quantum yield spectrum.
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Affiliation(s)
- Binbin Wu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Tian Liu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Yanling Wang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Guoqiang Zhao
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Baoliang Chen
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
| | - Chiheng Chu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China
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5
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Lin CJ, Wang PY, Lin YL, Chang ST, Hsu CS, Wu SP, Wu CH. Nonpolar Side Chains Affect the Photochemical Redox Reactions of Copper(II)-Amino Acid Complexes in Aqueous Solutions. ACS OMEGA 2021; 6:28194-28202. [PMID: 34723017 PMCID: PMC8552463 DOI: 10.1021/acsomega.1c04277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Photochemical redox reactions of Cu(II) complexes of eight amino acid ligands (L) with nonpolar side chains have been systematically investigated in deaerated aqueous solutions. Under irradiation at 313 nm, the intramolecular carboxylate-to-Cu(II) charge transfer within Cu(II)-amino acid complexes leads to Cu(I) formation and the concomitant decomposition of amino acids. All amino acid systems studied here can produce ammonia and aldehydes except proline. For the 1:1 Cu(II) complex species (CuL), the Cu(I) quantum yields at 313 nm (ΦCu(I),CuL) vary by fivefold and in the sequence (0.10 M ionic strength at 25 °C) alanine (0.094) > valine (0.059), leucine (0.059), isoleucine (0.056), phenylalanine (0.057) > glycine (0.052) > methionine (0.032) > proline (0.019). This trend can be rationalized by considering the stability of the carbon-centered radicals and the efficient depopulation of the photoexcited state, both of which are dependent on the side-chain structure. For the 1:2 Cu(II) complex species (CuL2), the Cu(I) quantum yields exhibit a similar trend and are always less than those for CuL. The photoformation rates of ammonia, Cu(I), and aldehydes are in the ratio of 1:2.0 ± 0.2:0.7 ± 0.2, which supports the proposed mechanism. This study suggests that the direct phototransformation of Cu(II)-amino acid complexes may contribute to the bioavailable nitrogen for aquatic microorganisms and cause biological damage on cell surfaces in sunlit waters.
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Affiliation(s)
- Chen-Jui Lin
- Department
of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Po-Yen Wang
- Department
of Civil Engineering, Widener University, Chester, Pennsylvania 19013, United States
| | - Yi-Liang Lin
- Department
of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Sheng-Te Chang
- Department
of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chao-Sheng Hsu
- Department
of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shu-Pao Wu
- Department
of Applied Chemistry, National Yang Ming
Chiao Tung University, Hsinchu 30010, Taiwan
| | - Chien-Hou Wu
- Department
of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute
of Analytical and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
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6
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Ossola R, Jönsson OM, Moor K, McNeill K. Singlet Oxygen Quantum Yields in Environmental Waters. Chem Rev 2021; 121:4100-4146. [PMID: 33683861 DOI: 10.1021/acs.chemrev.0c00781] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Singlet oxygen (1O2) is a reactive oxygen species produced in sunlit waters via energy transfer from the triplet states of natural sensitizers. There has been an increasing interest in measuring apparent 1O2 quantum yields (ΦΔ) of aquatic and atmospheric organic matter samples, driven in part by the fact that this parameter can be used for environmental fate modeling of organic contaminants and to advance our understanding of dissolved organic matter photophysics. However, the lack of reproducibility across research groups and publications remains a challenge that significantly limits the usability of literature data. In the first part of this review, we critically evaluate the experimental techniques that have been used to determine ΦΔ values of natural organic matter, we identify and quantify sources of errors that potentially explain the large variability in the literature, and we provide general experimental recommendations for future studies. In the second part, we provide a qualitative overview of known ΦΔ trends as a function of organic matter type, isolation and extraction procedures, bulk water chemistry parameters, molecular and spectroscopic organic matter features, chemical treatments, wavelength, season, and location. This review is supplemented with a comprehensive database of ΦΔ values of environmental samples.
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Affiliation(s)
- Rachele Ossola
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Oskar Martin Jönsson
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Kyle Moor
- Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, 84322 Logan, Utah, United States
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
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7
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Cai Y, Apell JN, Pflug NC, McNeill K, Bollmann UE. Photochemical fate of medetomidine in coastal and marine environments. WATER RESEARCH 2021; 191:116791. [PMID: 33433334 DOI: 10.1016/j.watres.2020.116791] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 06/12/2023]
Abstract
Medetomidine has been authorized in ship hull paints as an antifouling biocide under the biocidal product regulation in Europe since 2016. Its release into marine systems causes concerns over persistence and toxicity. However, the environmental fate of medetomidine has not been fully investigated. In this study, the photodegradation of medetomidine under natural sunlight conditions was investigated using collected coastal and sea waters. In addition, the phototransformation of medetomidine with reactive species (i.e., singlet oxygen, excited triplet state organic matter, and hydroxyl radicals) under UVA light was examined. Photoproducts were isolated by high-performance liquid chromatography (HPLC), identified by a combination of nuclear magnetic resonance (NMR) spectroscopy and time-of-flight mass spectrometry (qTOF), and reaction mechanisms were proposed. The results show that medetomidine is a neutral base (pKa of protonated form = 7.2) that leads to two different protonation states in the aquatic environment. Photodegradation of neutral medetomidine was dominated by reaction with singlet oxygen, while protonated medetomidine was relatively photostable. The contribution of reactive species to the overall photodegradation of neutral medetomidine was calculated to provide an assessment of phototransformation of medetomidine. The half-live of medetomidine was < 1.5 days in natural waters (pHcoastal = 8.3; pHsea = 8.1) under sunlit near-surface conditions, suggesting that it is not persistent in the aquatic environment. Because medetomidine has a relatively short half-life in sunlit aquatic ecosystems, a number of products, such as 2-(2,3-dimethylphenyl)propanamide, can be formed by photochemical reactions of medetomidine, with unknown consequences for marine and coastal waters.
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Affiliation(s)
- Yi Cai
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Jennifer N Apell
- Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland; Department of Civil and Urban Engineering, New York University Tandon School of Engineering, 6 Metrotech Center, Brooklyn, New York, 11201, USA
| | - Nicholas C Pflug
- Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland
| | - Kristopher McNeill
- Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland
| | - Ulla E Bollmann
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Geological Survey of Denmark and Greenland (GEUS), ØsterVoldgade 10, 1350 Copenhagen, Denmark.
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8
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Egli CM, Stravs MA, Janssen EML. Inactivation and Site-specific Oxidation of Aquatic Extracellular Bacterial Leucine Aminopeptidase by Singlet Oxygen. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14403-14412. [PMID: 33146524 DOI: 10.1021/acs.est.0c04696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Extracellular enzymes are master recyclers of organic matter, and to predict their functional lifetime, we need to understand their environmental transformation processes. In surface waters, direct and indirect photochemical transformation is a known driver of inactivation. We investigated molecular changes that occur along with inactivation in aminopeptidase, an abundant class of extracellular enzymes. We studied the inactivation kinetics and localized oxidation caused by singlet oxygen, 1O2, a major photochemically derived oxidant toward amino acids. Aminopeptidase showed second-order inactivation rate constants with 1O2 comparable to those of free amino acids. We then visualized site-specific oxidation kinetics within the three-dimensional protein and demonstrated that fastest oxidation occurred around the active site and at other reactive amino acids. However, second-order oxidation rate constants did not correlate strictly with the 1O2-accessible surface areas of those amino acids. We inspected site-specific processes by a comprehensive suspect screening for 723,288 possible transformation products. We concluded that histidine involved in zinc coordination at the active site reacted slower than what was expected by its accessibility, and we differentiated between two competing reaction pathways of 1O2 with tryptophan residues. This systematic analysis can be directly applied to other proteins and transformation reactions.
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Affiliation(s)
- Christine M Egli
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zürich 8092, Switzerland
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dubendorf 8600, Switzerland
| | - Michael A Stravs
- Institute of Molecular Systems Biology, ETH Zurich, Zürich 8093, Switzerland
| | - Elisabeth M L Janssen
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dubendorf 8600, Switzerland
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9
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Zhou H, Yan S, Lian L, Song W. Triplet-State Photochemistry of Dissolved Organic Matter: Triplet-State Energy Distribution and Surface Electric Charge Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2482-2490. [PMID: 30758190 DOI: 10.1021/acs.est.8b06574] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Excited triplet states of chromophoric dissolved organic matter (3CDOM*) are highly reactive species in sunlit surface waters and play a critical role in reactive oxygen species (ROS) formation and pollutant attenuation. In the present study, a series of chemical probes, including sorbic acid, sorbic alcohol, sorbic amine, trimethylphenol, and furfuryl alcohol, were employed to quantitatively determine 3CDOM* and 1O2 in various organic matters. Using a high concentration of sorbic alcohol as high-energy triplet states quencher, 3CDOM* can be first distinguished as high-energy triplet states (>250 kJ mol-1) and low-energy triplet states (<250 kJ mol-1). The terrestrial-origin natural organic matter (NOM) was found to mainly consist of low-energy triplet states, while high-energy triplet states were predominant in autochthonous-origin NOM and effluent/wastewater organic matter (EfOM/WWOM). The 1O2 quantum yields and electron transfer quantum yield coefficients ( fTMP) generated from low-energy triplet states remained constant in all tested organic matters. External phenolic compound showed quenching effects on triplet-state formation and tended to have a higher quenching efficiency for aromatic ketone triplet states, which are the main high-energy triplet states. In comparison with terrestrial-origin NOM, autochthonous-origin NOM and EfOM/WWOM presented lower reaction rate constants for sorbic amines and higher reaction rate constants for sorbic acid, and these differences are likely due to dissimilar surface electric charge conditions. Understanding the triplet-state photochemistry of CDOM is essential for providing useful insights into their photochemical effects in aquatic systems.
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Affiliation(s)
- Huaxi Zhou
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
| | - Shuwen Yan
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P. R. China
| | - Lushi Lian
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
| | - Weihua Song
- Department of Environmental Science & Engineering , Fudan University , Shanghai 200433 , P. R. China
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P. R. China
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10
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Chu C, Stamatelatos D, McNeill K. Aquatic indirect photochemical transformations of natural peptidic thiols: impact of thiol properties, solution pH, solution salinity and metal ions. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:1518-1527. [PMID: 29090717 DOI: 10.1039/c7em00324b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Natural peptidic thiols play numerous important roles in aquatic systems. While thiols are known to be susceptible to sensitized photoreaction, the photochemical transformation of thiols in surface waters remains largely unknown. This study systematically assessed the photochemical transformation of naturally occurring thiols, including arginylcysteine (RC), γ-glutamylcysteine (γEC), glutathione (GSH), and phytochelatin (PC) in solutions containing dissolved organic matter (DOM). The results show that all thiols underwent rapid indirect photochemical transformation. The transformation rates of thiols were highly pH-dependent and increased with increasing solution pH. γEC and GSH show lower transformation rates than free Cys, which was ascribed to their higher thiol pKa values. In comparison, PC and RC show much higher transformation rates than γEC and GSH, due to more reactive thiol groups contained in the PC molecule and sorption of RC to DOM macromolecules, respectively. While all investigated pathways contributed to thiol transformation, hydroxyl radical-mediated oxidation dominated at low solution pH and singlet oxygen-mediated oxidation dominated at high solution pH in the DOM-sensitized phototransformations of γEC, GSH, and PC. Furthermore, the effects of metal complexation and solution salinity on thiol transformation rates were examined. Thiol reactivity was not affected by Fe3+ and Ag+, slightly enhanced in the presence of Zn2+, Cd2+ and Hg2+, and significantly enhanced by Cu2+. Additionally, enhanced thiol transformation rates were observed in solutions with high salinity.
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Affiliation(s)
- Chiheng Chu
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland.
| | - Dimitrios Stamatelatos
- 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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11
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Pignatello JJ, Mitch WA, Xu W. Activity and Reactivity of Pyrogenic Carbonaceous Matter toward Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8893-8908. [PMID: 28753285 DOI: 10.1021/acs.est.7b01088] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pyrogenic carbonaceous matter (PCM) includes environmental black carbon (fossil fuel soot, biomass char), engineered carbons (biochar, activated carbon), and related materials like graphene and nanotubes. These materials contact organic pollutants due to their widespread presence in the environment or through their use in various engineering applications. This review covers recent advances in our understanding of adsorption and chemical reactions mediated by PCM and the links between these processes. It also covers adsorptive processes previously receiving little attention and ignored in models such as steric constraints, physicochemical effects of confinement in nanopores, π interactions of aromatic compounds with polyaromatic surfaces, and very strong hydrogen bonding of ionizable compounds with surface functional groups. Although previous research has regarded carbons merely as passive sorbents, recent studies show that PCM can promote chemical reactions of sorbed contaminants at ordinary temperature, including long-range electron conduction between molecules and between microbes and molecules, local redox reactions between molecules, and hydrolysis. PCM may itself contain redox-active functional groups that are capable of oxidizing or reducing organic compounds and of generating reactive oxygen species (ROS) from oxygen, peroxides, or ozone. Amorphous carbons contain persistent free radicals that may play a role in observed redox reactions and ROS generation. Reactions mediated by PCM can impact the biogeochemical fate of pollutants and lead to useful strategies for remediation.
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Affiliation(s)
- J J Pignatello
- Department of Environmental Sciences, The Connecticut Agricultural Experiment Station , New Haven, Connecticut 06504-1106, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University , 473 Via Ortega, Stanford, California 94305, United States
| | - Wenqing Xu
- Department of Civil and Environmental Engineering, Villanova University , Villanova, Pennsylvania 19085, United States
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12
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Ren D, Huang B, Yang B, Pan X, Dionysiou DD. Mitigating 17α-ethynylestradiol water contamination through binding and photosensitization by dissolved humic substances. JOURNAL OF HAZARDOUS MATERIALS 2017; 327:197-205. [PMID: 28068644 DOI: 10.1016/j.jhazmat.2016.12.054] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/25/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
Photodegradation is an important abiotic pathway transforming organic pollutants in natural waters. Humic substances (HS), including humic and fulvic acids, are capable of accelerating the photodegradation of steroid estrogens. However, how the photodegradtion of the emerging pollutants influenced by HS is not clear. Thus, we studied the roles and mechanisms of HS in inducing the photodegradation of 17α-ethynylestradiol (EE2). HS generally induces EE2 photodegradation through binding and reactive species generation. Apart from hydroxyl radical (HO), the excited triplets of humic substances (3HS*) are other key reactive species degrading EE2 by abstracting electrons. HO and 3HS* were responsible for about 60% of the overall EE2 photodegradation at 250μmol HS L-1. Most of EE2 molecules bound to the HS via H-bonding, π-π and hydrophobic interactions. The binding role of HS in promoting EE2 photodegradation was rationalized by 17β-estradiol competitive binding with EE2 to the humic and fulvic acids. Furthermore, HS-promoted photodegradation can alter EE2 toxicity to wheat, rice and Ormosia plants. This study extends our knowledge on the photochemical behaviors and ecological risks of steroid estrogens in natural waters.
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Affiliation(s)
- Dong Ren
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Benqin Yang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Xuejun Pan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
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13
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Lundeen RA, Chu C, Sander M, McNeill K. Photooxidation of the Antimicrobial, Nonribosomal Peptide Bacitracin A by Singlet Oxygen under Environmentally Relevant Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8586-8595. [PMID: 27128169 DOI: 10.1021/acs.est.6b01131] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Bacitracin is a mixture of nonribosomal peptides (NRPs) that is extensively used as an antibiotic in both human and veterinary medicine. Despite its widespread use over the past six decades, very few studies have addressed the environmental fate of bacitracin and zinc-bacitracin complexes. In this study, the photochemical transformation of bacitracin components (i.e., cyclic dodecapeptides) in the aquatic environment was investigated. A high resolution mass spectrometry (HRMS)-based approach enabled monitoring of the photochemical degradation kinetics of individual bacitracin components, investigation of the relative contribution of reactive oxygen species (e.g., singlet oxygen, (1)O2) in dissolved organic matter-sensitized photoreactions, and identification of oxidative modifications in bacitracin photoproducts. The results of this study support the hypothesis that indirect photochemical oxidation of the histidine (His) residue by (1)O2 is a major degradation pathway for bacitracin A, the most potent congener of the mixture. Furthermore, the photooxidation rate of bacitracin A with (1)O2 decreased upon bacitracin A coordination with Zn(2+), demonstrating that the photochemistry of metal-bound His is different from that of metal-free His. Overall, these results provide insight into the fate of bacitracin components in the aquatic environment and highlight the potential of utilizing this HRMS-based methodology to study transformations of other environmentally relevant NRPs.
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Affiliation(s)
- Rachel A Lundeen
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
| | - Chiheng Chu
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
| | - Michael Sander
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
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14
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Chu C, Erickson PR, Lundeen RA, Stamatelatos D, Alaimo PJ, Latch DE, McNeill K. Photochemical and Nonphotochemical Transformations of Cysteine with Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6363-6373. [PMID: 27172378 DOI: 10.1021/acs.est.6b01291] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cysteine (Cys) plays numerous key roles in the biogeochemistry of natural waters. Despite its importance, a full assessment of Cys abiotic transformation kinetics, products and pathways under environmental conditions has not been conducted. This study is a mechanistic evaluation of the photochemical and nonphotochemical (dark) transformations of Cys in solutions containing chromophoric dissolved organic matter (CDOM). The results show that Cys underwent abiotic transformations under both dark and irradiated conditions. Under dark conditions, the transformation rates of Cys were moderate and were highly pH- and temperature-dependent. Under UVA or natural sunlight irradiations, Cys transformation rates were enhanced by up to two orders of magnitude compared to rates under dark conditions. Product analysis indicated cystine and cysteine sulfinic acid were the major photooxidation products. In addition, this study provides an assessment of the contributions of singlet oxygen, hydroxyl radical, hydrogen peroxide, and triplet dissolved organic matter to the CDOM-sensitized photochemical oxidation of Cys. The results suggest that another unknown pathway was dominant in the CDOM-sensitized photodegradation of Cys, which will require further study to identify.
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Affiliation(s)
- Chiheng Chu
- 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
| | - Rachel A Lundeen
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
| | - Dimitrios Stamatelatos
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zurich , 8092 Zurich, Switzerland
| | - Peter J Alaimo
- Department of Chemistry, Seattle University , Seattle, Washington 98122, United States
| | - Douglas E Latch
- Department of Chemistry, Seattle University , Seattle, Washington 98122, 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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15
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Li R, Zhao C, Yao B, Li D, Yan S, O'Shea KE, Song W. Photochemical Transformation of Aminoglycoside Antibiotics in Simulated Natural Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2921-2930. [PMID: 26886506 DOI: 10.1021/acs.est.5b05234] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Aminoglycoside antibiotics are widely used in human therapy and veterinary medicine. We report herein a detailed study on the natural-organic-matter- (NOM-) photosensitized degradation of aminoglycosides in aqueous media under simulated solar irradiation. It appears that the direct reaction of the excited states of NOM ((3)NOM*) with aminoglycosides is minor. The contributions of reactive oxygen species (ROSs) in the bulk solutions are also unimportant, as determined by an assessment based on steady-state concentrations and bimolecular reaction rate constants in a homogeneous reaction model. The inhibition of the photodegradation by isopropamide is rationalized through competitive sorption with aminoglycosides on the NOM surface, whereas the addition of isopropanol negligibly affects degradation because it quenches HO(•) in the bulk solution but not HO(•) localized on the NOM surface where aminoglycosides reside. Therefore, a sorption-enhanced phototransformation mechanism is proposed. The sorption of aminoglycosides on NOM follows a dual-mode model involving Langmuir and linear isotherms. The steady-state concentration of HO(•) on the surface of NOM was calculated as 10(-14) M, 2 orders of magnitude higher than that in the bulk solution. This fundamental information is important in the assessment of the fate and transport of aminoglycosides in aqueous environments.
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Affiliation(s)
- Rui Li
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
| | - Cen Zhao
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
| | - Bo Yao
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
| | - Dan Li
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
| | - Kevin E O'Shea
- Department of Chemistry & Biochemistry, Florida International University , Miami, Florida 33199, United States
| | - Weihua Song
- Department of Environmental Science & Engineering, Fudan University , Shanghai 200433, China
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