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Shams M, Guiney LM, Ramesh M, Hersam MC, Chowdhury I. Effects of sunlight on the fate of graphene oxide and reduced graphene oxide nanomaterials in the natural surface water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162427. [PMID: 36841399 DOI: 10.1016/j.scitotenv.2023.162427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/19/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
Graphene nanomaterials have been commercialized for use in the electronic and biomedical industries, increasing their dissemination into surface waters and subsequent transformation in natural aquatic environment. While the photodegradation of graphene oxide nanomaterials has been investigated in the past, previous research did not consider actual natural aquatic environment and also focused on primarily graphene oxide nanomaterials. In this study, photodegradation of graphene nanomaterials with varying oxidation levels, including graphene oxide (GO) and partially reduced graphene oxide (rGO-2 h) are evaluated in Columbia River Water and compared with each other. Our results indicate that both direct and indirect photolysis of graphene-based nanomaterials will occur simultaneously in natural surface water. However, environmentally relevant concentrations of photosensitizers in surface water are not capable of producing sufficient ·OH to initiate degradation of GO via indirect photolysis. For all conditions tested, GO showed more rapid photodegradation compared to rGO. Overall, direct and indirect photodegradation of graphene oxide nanomaterials in natural surface water is minimal and slow indicating that phototransformation of graphene-based nanomaterials will be insignificant in natural surface water.
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Affiliation(s)
- Mehnaz Shams
- Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164, USA
| | - Linda M Guiney
- Departments of Materials Science and Engineering, Chemistry, and Medicine, Northwestern University, Evanston, IL 60208, USA
| | - Mani Ramesh
- Departments of Materials Science and Engineering, Chemistry, and Medicine, Northwestern University, Evanston, IL 60208, USA
| | - Mark C Hersam
- Departments of Materials Science and Engineering, Chemistry, and Medicine, Northwestern University, Evanston, IL 60208, USA
| | - Indranil Chowdhury
- Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164, USA.
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2
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Ahn Y, Park S, Ji MK, Ha GS, Jeon BH, Choi J. Biodiesel production potential of microalgae, cultivated in acid mine drainage and livestock wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 314:115031. [PMID: 35468431 DOI: 10.1016/j.jenvman.2022.115031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
The adaptability and biofuel production potential of two strains of microalgae isolated and cultivated in livestock wastewater effluent (LWE) with acid mine drainage (AMD) were investigated. The isolated strains of microalgae from samples obtained from LWE and AMD, two microalgal strains (Nephroselmis sp. KGE2 and Autodesmus obliquus KGE17) were selected based on their growth rate and lipid productivity. The dry cell weight of Nephroselmis sp. KGE2 and Autodesmus obliquus KGE17 after 20 days of cultivation in AMD increased from 0.05 to 0.59 g/L and from 0.05 to 0.55 g/L, respectively. These findings revealed a significant accumulation of fatty acids with increasing AMD content. Nephroselmis sp. KGE2 in LWE with 5% AMD demonstrated a higher growth rate (0.59 ± 0.03 g/L) and fatty acid production (401.5 ± 47.3 mg/L) than Autodesmus obliquus KGE17 with 5% AMD. Additionally, Nephroselmis sp. KGE2 had C16-C18 fatty acid content (92.4%) in LWE with AMD. Biodiesel produced from Nephroselmis sp. KGE2 had a higher cetane number (52.31) and iodine value (88.26 g I2/100 g oil). Consequently, Nephroselmis sp. KGE2 can be considered a potential candidate for biodiesel production using AMD as an iron source.
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Affiliation(s)
- Yongtae Ahn
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Hwarang-ro 14, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Sanghyun Park
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Hwarang-ro 14, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Min-Kyu Ji
- Korea Environment Institute, 370 Sicheong-daero, Sejong, 30147, Republic of Korea
| | - Geon-Soo Ha
- Department of Earth Resources & Environmental Engineering, Hanyang University, 222-Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Byong-Hun Jeon
- Department of Earth Resources & Environmental Engineering, Hanyang University, 222-Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Jaeyoung Choi
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Hwarang-ro 14, Seongbuk-gu, Seoul, 02792, Republic of Korea.
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Zhang Y, Zhang R, Li SL, Mostofa KMG, Fu X, Ji H, Liu W, Sun P. Photo-ammonification of low molecular weight dissolved organic nitrogen by direct and indirect photolysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142930. [PMID: 33131884 DOI: 10.1016/j.scitotenv.2020.142930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/26/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
The photo-ammonification process plays a crucial role in the transformation of dissolved organic nitrogen (DON) to dissolved inorganic nitrogen (DIN). However, previous studies have primarily focused on DON biotransformation than on abiotic processes. This study investigated the photo-ammonification process of nine model low molecular weight (LMW) DON molecules (e.g., amino acids, nucleotides, and urea) under the influence of different light sources. The results showed that photo-ammonification of model DON was mainly induced by UV light, while negligible contribution by visible light was found. Depending on their molecular structures, amino acids yielded different ammonia amounts, whereas negligible photo-ammonification was observed for nucleotides and urea. As for the reactive species, OH promoted ammonia yields of all the model amino acids; 3CDOM⁎ contributed to the photo-ammonification of six amino acids; 1O2 only had a positive impact on ammonification of tryptophan, histidine, and tyrosine; and CO3- accelerated ammonia generation from histidine and methionine. In natural water samples, tryptophan, tyrosine, histidine, and methionine generated significant ammonia. OH and 1O2 were speculated as the contributing reactive species based on kinetic studies as well as significant fluorescent humic-like and tyrosine-like substances degradation in irradiated samples compared to the raw samples characterized by the EEM-PARAFAC analysis. The negative linear correlations between photo-ammonification rates and the ELUMO-EHOMO of the amino acids emphasized the importance of the role of the molecular structure. Overall, these results revealed the LMW DON photo-ammonification mechanism in sunlit surface waters and highlighted its significance in the nitrogen biogeochemical cycle as well as water quality management.
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Affiliation(s)
- Yutong Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
| | - Ruochun Zhang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China.
| | - Si-Liang Li
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
| | - Khan M G Mostofa
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim, Tianjin University, Tianjin 300072, China
| | - Xiaoli Fu
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China
| | - Haodong Ji
- The Key Laboratory of Water and Sediment Science, Ministry of Education, China; College of Environment Science and Engineering, Peking University, Beijing 100871, China
| | - Wen Liu
- The Key Laboratory of Water and Sediment Science, Ministry of Education, China; College of Environment Science and Engineering, Peking University, Beijing 100871, China
| | - Peizhe Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
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Rivera-Dávila OL, Sánchez-Martínez G, Rico-Martínez R. Ecotoxicity of pesticides and semiochemicals used for control and prevention of conifer bark beetle (Dendroctonus spp.) outbreaks. CHEMOSPHERE 2021; 263:128375. [PMID: 33297283 DOI: 10.1016/j.chemosphere.2020.128375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
Application of pyrethroid pesticides and semiochemicals are two treatments used worldwide to control conifer bark beetles (Dendroctonus spp.); their residues can reach water reservoirs and water currents through run off and affect non-target organisms such as freshwater invertebrates. Therefore, we assessed the 48-h lethal toxicity, chronic toxicity (reproduction inhibition), and bioaccumulation of three pyrethroid pesticides (bifenthrin, cypermethrin, and deltamethrin) and two semiochemicals (verbenone and 3-methyl-2-cyclohexen-1-one) in two freshwater invertebrates: the cladoceran Alona guttata and the rotifer Lecane papuana. Bifenthrin was the most toxic of the five chemical compounds tested followed by deltamethrin and then cypermethrin, which was the least toxic pyrethroid for both species. Semiochemicals were far less toxic than pyrethroids and verbenone was most toxic than 3-methyl-2-cyclohexen-1-one for both species. For the rotifer Lecane papuana, the pyrethroid with the highest Bioconcentration Factor was bifenthrin, and for the semiochemicals it was 3-methyl-2-cyclohexen-1-one. For the cladoceran Alona guttata, the pyrethroid with the highest bioconcentration factor was cypermethrin and for the semiochemicals it was verbenone. The pyrethroid with highest body burdens both lethal and chronic was cypermethrin. Semiochemicals showed lethal and chronic body burdens 12-fold higher than pyrethroids and were therefore less toxic than pyrethroids. These results showed that the semiochemicals verbenone and 3-methyl-2-cyclohexen-1-one are a safe tool for the freshwater invertebrates tested when compared with pyrethroid pesticides. Cypermethrin was the least toxic of the pyrethroids tested and therefore could be considered as a good candidate to control outbreaks of the conifer bark beetle.
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Affiliation(s)
- Olga Lidia Rivera-Dávila
- Universidad Autónoma de Aguascalientes, Centro de Ciencias Básicas, Departamento de Química, Avenida Universidad 940, Aguascalientes, Aguascalientes, C.P. 20131, Mexico
| | - Guillermo Sánchez-Martínez
- Centro de Investigación Regional Norte Centro, Campo Experimental Pabellón, INIFAP, Km. 32.5 Carretera Aguascalientes-Zacatecas, Pabellón de Arteaga, Ags. C.P, 20670, Mexico.
| | - Roberto Rico-Martínez
- Universidad Autónoma de Aguascalientes, Centro de Ciencias Básicas, Departamento de Química, Avenida Universidad 940, Aguascalientes, Aguascalientes, C.P. 20131, Mexico.
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Muhammad N, Zhang Y, Li W, Zhao YG, Ali A, Subhani Q, Mahmud T, Liu J, Cui H, Zhu Y. Determination of nitenpyram and 6-chloronicotinic acid in environmental samples by ion chromatography coupled with online photochemically induced fluorescence detector. J Sep Sci 2018; 41:4096-4104. [PMID: 30230241 DOI: 10.1002/jssc.201800612] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 12/18/2022]
Abstract
A simple, cost-effective, sensitive, and quick method for the determination of nitenpyram and its metabolite 6-chloronicotinic acid in environmental samples was developed by coupling an ion chromatograph with a fluorescence detector and a post-column photochemical reactor. This developed analytical method involved a rapid sample extraction by modified and miniaturized quick, easy, cheap, effective, rugged, and safe method followed by isocratic ion chromatographic separation of nitenpyram and 6-chloronicotinic acid into an IonPac™ AS11-HC column protected by IonPac™ AG11A guard column by running 30 mM NaOH + 10% acetonitrile mobile phase. A homemade post-column photochemical reactor was also integrated with the ion chromatographic system for online transformation of both analytes into their respective highly fluorescent photoproduct in basic media without using an extra pump. The developed method was validated by following SANTE/11945/2015 guidelines on analytical quality control and validation procedures. The method showed a good linear response (r > 0.999), improved limit of detection (0.101-0.132 μg/L), minimum or no matrix effect, excellent recoveries (90.2-100.10%) and relative standard deviations were found to be ≤6.50%.
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Affiliation(s)
- Nadeem Muhammad
- Department of Environmental Engineering, Wuchang University of Technology, Wuhan, P. R. China.,Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
| | - Yun Zhang
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
| | - Weixia Li
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
| | - Yong-Gang Zhao
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
| | - Amjad Ali
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
| | - Qamar Subhani
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China.,Higher Education Department, Punjab, Lahore, Pakistan
| | - Tariq Mahmud
- Institute of Chemistry, University of the Punjab, Lahore, Pakistan
| | - Junwei Liu
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China.,Department of Applied Chemistry, Zhengzhou University of Light Industry, Zhengzhou, P. R. China
| | - Hairong Cui
- Department of Environmental Engineering, Wuchang University of Technology, Wuhan, P. R. China
| | - Yan Zhu
- Department of chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
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Emídio ES, Calisto V, de Marchi MRR, Esteves VI. Photochemical transformation of zearalenone in aqueous solutions under simulated solar irradiation: Kinetics and influence of water constituents. CHEMOSPHERE 2017; 169:146-154. [PMID: 27870936 DOI: 10.1016/j.chemosphere.2016.11.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 10/31/2016] [Accepted: 11/08/2016] [Indexed: 06/06/2023]
Abstract
The presence of estrogenic mycotoxins, such as zearalenone (ZEN), in surface waters is an emerging environmental issue. Little is known about its phototransformation behavior, which may influence its environmental fate. In this context, the phototransformation of ZEN was investigated in pure water, river water and estuarine water using simulated sunlight irradiation. Kinetic studies revealed that two concomitant processes contribute to the fate of ZEN under solar irradiation: photoisomerization and photodegradation. This phototransformation followed a pseudo-first order kinetics. ZEN degrades quickly in natural waters and slowly in deionized water, with half-lives (t1/2) of 28 ± 4 min (estuarine water), 136 ± 21 min (river water) and 1777 ± 412 min (deionized water). The effects of different water constituents on the phototransformation of ZEN in aqueous solution have been assessed (NaCl, Ca2+, Mg2+, Fe3+, NO3- and oxalate ions, synthetic seawater, Fe(III)-oxalate and Mg(II)-oxalate complexes, humic acids, fulvic acids and XAD-4 fraction). In the presence of synthetic seawater salt (t1/2 = 18 ± 5 min) and Fe(III)-oxalate complexes (t1/2 = 61 ± 9 min), the transformation rate increased considerably in relation to other water constituents tested. The solution pH also had a considerable effect in the kinetics with maximum transformation rates occurring around pH 8.5. These results allow us to conclude that phototransformation by solar radiation can be an important degradation pathway of ZEN in natural waters.
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Affiliation(s)
- Elissandro S Emídio
- Analytical Chemistry Department, Chemistry Institute, São Paulo State University-UNESP, Araraquara, SP, 14801-970, Brazil
| | - Vânia Calisto
- Department of Chemistry and CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal.
| | - Mary Rosa R de Marchi
- Analytical Chemistry Department, Chemistry Institute, São Paulo State University-UNESP, Araraquara, SP, 14801-970, Brazil
| | - Valdemar I Esteves
- Department of Chemistry and CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal.
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Vione D, Minella M, Maurino V, Minero C. Indirect photochemistry in sunlit surface waters: photoinduced production of reactive transient species. Chemistry 2014; 20:10590-606. [PMID: 24888627 DOI: 10.1002/chem.201400413] [Citation(s) in RCA: 259] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Indexed: 11/09/2022]
Abstract
This paper gives an overview of the main reactive transient species that are produced in surface waters by sunlight illumination of photoactive molecules (photosensitizers), such as nitrate, nitrite, and chromophoric dissolved organic matter (CDOM). The main transients (˙OH, CO3(-˙) , (1)O2, and CDOM triplet states) are involved in the indirect phototransformation of a very wide range of persistent organic pollutants in surface waters.
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Affiliation(s)
- Davide Vione
- Department of Chemistry, University of Torino, Via Pietro Giuria 5, 10125 Torino (Italy), Fax: (+39) 011-6705242; NatRisk Inter-Department Centre, University of Torino, Via Leonardo Da Vinci 44, 10095 Grugliasco (TO) (Italy).
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Bower JP, Anastasio C. Degradation of organic pollutants in/on snow and ice by singlet molecular oxygen (¹O₂*) and an organic triplet excited state. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:748-756. [PMID: 24487942 DOI: 10.1039/c3em00565h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Singlet molecular oxygen (¹O₂*) can be a significant sink for a variety of electron-rich pollutants in surface waters and atmospheric drops. We recently found that ¹O₂* concentrations are enhanced by up to a factor of 10(4) on illuminated ice compared to in the equivalent liquid solution, suggesting that ¹O₂* could be an important oxidant for pollutants in snow. To examine this, here we study the degradation of three model organic pollutants: furfuryl alcohol (to represent furans), tryptophan (for aromatic amino acids), and bisphenol A (for phenols). Each compound was studied in illuminated aqueous solution and ice containing Rose Bengal (RB, a sensitizer for ¹O₂*) and sodium chloride (to adjust the concentration of total solutes). The RB-mediated loss of each organic compound is enhanced on illuminated ice compared to in solution, by factors of 6400 for furfuryl alcohol, 8300 for tryptophan, and 50 for bisphenol A for ice containing 0.065 mM total solutes. Rates of loss of furfuryl alcohol and tryptophan decrease at a higher total solute concentration, in qualitative agreement with predictions from freezing-point depression. In contrast, the loss of bisphenol A on ice is independent of total solute concentration. Relative to liquid tests, the enhanced loss of tryptophan on ice during control experiments made with deoxygenated solutions and solutions in D₂O show that the triplet excited state of Rose Bengal may also contribute to loss of pollutants on ice.
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Affiliation(s)
- Jonathan P Bower
- Department of Land, Air, and Water Resources, University of California, One Shields Avenue, Davis, CA 95616, USA.
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Nkhili E, Boguta P, Bejger R, Guyot G, Sokołowska Z, Richard C. Photosensitizing properties of water-extractable organic matter from soils. CHEMOSPHERE 2014; 95:317-323. [PMID: 24083904 DOI: 10.1016/j.chemosphere.2013.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 08/23/2013] [Accepted: 09/02/2013] [Indexed: 06/02/2023]
Abstract
Water-extractable organic matter (WEOM) was extracted using pure water from two black soils and from the Elliott reference soil of the International Humic Substances Society (IHSS). WEOMs were characterized by chemical and spectroscopic methods. The apparent quantum yields of singlet oxygen, triplet excited states and hydroxyl radicals formation upon irradiation within the wavelength range 290-450 nm were determined using chemical probes and compared to those of standard Elliott humic substances. In general, the aromatic content, as measured by the SUVA value, was close in WEOMs and humic substances, while the E2/E3 was higher and the humification index lower in the former. Quantum yield values measured for WEOMs fell within the range of those found for basic medium extracted humic substances or were even higher in one case. Thus, water soluble aromatic moiety of the soil organic matter, especially those with low humification degree, is important for the photosensitizing properties. We also found that WEOMs sensitized the bisphenol A phototransformation with rates of the same order of magnitude for all the samples.
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Affiliation(s)
- Ezzhora Nkhili
- Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, 63000 Clermont-Ferrand, France
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Identification of singlet oxygen photosensitizes in lambs drinking water in an alveld risk area in West Norway. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2012; 119:37-45. [PMID: 23313826 DOI: 10.1016/j.jphotobiol.2012.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/26/2012] [Accepted: 12/10/2012] [Indexed: 11/22/2022]
Abstract
Alveld is a hepatogenous photosensitivity disorder in lambs. Although alveld has been known in Norway for more than 100years, there are still questions related to the cause of the disease. Phytoporphyrin has long been incriminated as the photosensitizer in hepatogenous photosensitivity diseases but previous findings suggest that the photosensitizing mechanism in alveld is more complex, possibly involving other co-factors. The current work investigates the presence of non-hepatogenous photosensitizers originating in lamb's drinking water from various sources. In addition samples of two of the predominent cyanobacteria found in a representative biofilm (i.e. aggregates of microbes) were identified and isolated in axenic (i.e. pure) cultures. Information from the absorption-, fluorescence emission-, and -excitation spectra and the action spectrum for the formation of singlet oxygen was combined in order to identify the chromophores responsible for the formation of singlet oxygen, e.g. phycocyanins from the cyanobacteria. The highest level of singlet oxygen formation was detected in lotic (i.e. flowing) water in the period consistent with the outbreak of the alveld disease in the area. Meteorological data indicate a warm and wet May with a high radiation exposure leading up to a colder and wet June with an even higher solar irradiance. The seasonal variation in the amount of photosensitizers in lamb's drinking water combined meteorological data can be important to predict the outbreak of alveld.
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Yin Y, Liu J, Jiang G. Sunlight-induced reduction of ionic Ag and Au to metallic nanoparticles by dissolved organic matter. ACS NANO 2012; 6:7910-7919. [PMID: 22816495 DOI: 10.1021/nn302293r] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Despite the possible occurrence of metal nanoparticles in the environment due to the discharge of engineered nanoparticles and the natural transformation of metal ions into metal nanoparticles, little is known about the transformation mechanism, fates, behaviors, and effects of these nanoparticles in the environment. Here, we show that dissolved organic matter (DOM) in environmental waters can mediate the reduction of ionic Ag and Au to their metallic nanoparticles under natural sunlight, suggesting that this process may be general for metals with high reduction potential. We demonstrated that the reduction was mediated by superoxide from photoirradiation of the phenol group in DOM, and the dissolved O(2) significantly enhanced the formation of Ag nanoparticles. These results imply that previous knowledge about O(2)-induced dissolution and its effect on persistence of Ag nanoparticles should be reconsidered in a sunlit DOM-rich aqueous environment. This study can also shed light on understanding possible natural sources of Ag and Au nanoparticles in the aquatic environment, which is possibly critical in the supergene enrichment of Ag and Au.
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Affiliation(s)
- Yongguang Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Anti-UVC irradiation and metal chelation properties of 6-benzoyl-5,7-dihydroxy-4-phenyl-chromen-2-one: an implications for anti-cataract agent. Int J Mol Sci 2011; 12:7059-76. [PMID: 22072936 PMCID: PMC3211027 DOI: 10.3390/ijms12107059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/23/2011] [Accepted: 10/11/2011] [Indexed: 02/05/2023] Open
Abstract
Coumarin derivative 1, 5,7-dihydroxy-6-(3-methyl-1-butyryl)-4-phenyl-chromen- 2-one, has been reported to possess radical scavenging activity and DNA protection. We have synthesized a series of coumarins with structural modifications at positions C4, C5, C6 and C7 and evaluated them for their anti-UVC properties. Coumarin 7, 6-benzoyl-5,6-dihydroxy-4-phenyl-chromen-2-one, was found to have the most potent activity in protecting porcine γ-crystallin against UVC insults. Results of fluorescence assays indicated that compound 7 was capable of decreasing the loss of intensity while lens crystallins and DNA PUC19 were irradiated with UVC. Presence of compound 7 decreased hydroxyl radical levels determined by probe 1b and the free iron concentrations determined by Ferrozine reagent. The chelation assay showed that compound 7 was chelated to metal via 6-CO and 5-OH on the benzopyrone ring. The observed protective effects of compound 7 towards crystallins from insults of UVC and free radicals may be due to its iron-chelating activity and its peak absorption at 254 nm.
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Abstract
To understand the degradation and environmental fate of pyrethroids, the process of their photodegradation under simulated natural conditions was investigated. The results showed that the degradation process follows first-order kinetics. The degradation intermediates were identified with gas chromatography-mass spectrometry. A plausible mechanism was discussed to explain the process. Several influences on degradation process were investigated and reported such as the effects of initial concentration of pyrethroids, total time of light irradiation, solvents, and light source, as well as the effect of a few substances that exist in the environment. This study could be a good reference for the degradation of pyrethroids in practical circumstances.
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Affiliation(s)
- Pengyan Liu
- College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
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