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Ding L, Yu X, Guo X, Zhang Y, Ouyang Z, Liu P, Zhang C, Wang T, Jia H, Zhu L. The photodegradation processes and mechanisms of polyvinyl chloride and polyethylene terephthalate microplastic in aquatic environments: Important role of clay minerals. WATER RESEARCH 2022; 208:117879. [PMID: 34847511 DOI: 10.1016/j.watres.2021.117879] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 06/13/2023]
Abstract
It is well known that microplastics (MPs) may experience weathering and aging under ultraviolet light (UV) irradiation, but it remains unclear if these processes are impacted by natural components, such as clay minerals. In this study, we systematically investigated the photodegradation behaviors of polyvinyl chloride (PVC) and poly (ethylene terephthalate) (PET), two utmost used plastics, in the presence of clay minerals (kaolinite and montmorillonite). The results demonstrated that the clay minerals, particularly kaolinite, significantly promoted the MPs photodegradation, and the aging of PET was more prominent. The photodegradation was the most distinct at pH 7.0, regardless of the presence or absence of the clay minerals. The results of electron paramagnetic resonance and inhibition experiments of reactive oxygen species indicated that the minerals, particularly kaolinite, remarkably facilitated production of •OH, which was the key species contributing to the photodegradation of MPs. Specifically, UV irradiation facilitated the photo-ionization of MPs, producing hydrated electrons and MP radical cations (MP+). The Lewis base sites prevalent on the clay siloxane surfaces could stabilize the MP radical cations and prevent their recombination with hydrated electrons, which promoted the generation of •OH under aerobic conditions, and facilitated the degradation of MP. Two-dimensional (2D) Fourier transformation infrared (FTIR) correlation spectroscopy (COS) analysis and ultra-high-performance liquid chromatography coupled to a Q Exactive Orbitrap HF mass spectrometer were used to identify the sequential changes of functional groups, and the degradation products of the MPs. This study improves our understanding on the aging of MPs in the complex natural environment.
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Affiliation(s)
- Ling Ding
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiaoqin Yu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xuetao Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
| | - Yaping Zhang
- School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhuozhi Ouyang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Peng Liu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Chi Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Tiecheng Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Hanzhong Jia
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Lingyan Zhu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
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Wei CJ, Li XY, Xie YF, Wang XM. Direct photo transformation of tetracycline and sulfanomide group antibiotics in surface water: Kinetics, toxicity and site modeling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:1-9. [PMID: 31174004 DOI: 10.1016/j.scitotenv.2019.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 03/10/2019] [Accepted: 04/03/2019] [Indexed: 05/17/2023]
Abstract
The direct photo-transformation of widely used antibiotics, including Tetracycline (TTC), chlortetracycline (CTC), sulfamethoxazole (SMX) and sulfamethazine (SMZ) were quantified for surface water by using artificial UV irradiation. The photolysis rate is directly proportional to the overlap between the absorption spectrum of the solution and the spectrum of the terrestrial sunlight. Increasing overlap fraction of Tetracycline (TC) group than Sulfanomide (Sulfa) group, the transformation of TC group is certified much faster than the sulfa group. The speciation of TC and Sulfa group antibiotics are pH-dependent and consequently influence its light adsorption spectrum. And the toxicity of the four target antibiotics along the photo-transformation was assessed. In field aquatic environment, a temporal- and spatial half-life model described the behavior of the antibiotics in water column of victoria harbour could be validated by using experimentally obtained quantum yield with the target field meteorological data. The modeling results indicated the photolysis rate of different kind of antibiotics varied differently along season, daily time and water depth. Summer, midday and surface layer of water body would be the time- and space-highlight spot in which the phototransformation are the dominant process for antibiotics concentration depletion. Seasonal variety would be enhanced for sulfa-group kind antibiotics, which having only tail overlapped with irradiation spectrum. Daily averaged half-lives of TC group were relatively stable, while the sulfa group antibiotics were found to vary from about 300 to 750 h, dependent on the seasonal change.
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Affiliation(s)
- Cai-Jie Wei
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Xiao-Yan Li
- Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong
| | - Yue-Feng Xie
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Civil and Environmental Engineering Programs, The Pennsylvania State University, Middletown, PA 17057, USA
| | - Xiao-Mao Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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Jin X, Wu D, Ling J, Wang C, Liu C, Gu C. Hydrolysis of Chloramphenicol Catalyzed by Clay Minerals under Nonaqueous Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10645-10653. [PMID: 31401828 DOI: 10.1021/acs.est.9b02119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Soil contamination with antibiotics has raised great environmental concerns, while the abiotic degradation of antibiotics on drought soil particles has been largely ignored. In this study, we examined the transformation of chloramphenicol (CAP) on phyllosilicates under nonaqueous conditions. A significant hydrolysis of CAP mediated by kaolinite occurred under moderate relative humidities (RH: 33-76%) with the half-lives of 10-20 days. By contrast, incubation with montmorillonite did not result in detectable degradation of CAP. Infrared and Raman spectroscopies together with density functional theory calculations suggested that the surface-catalyzed CAP hydrolysis was mainly attributed to the basal plane hydroxyl groups of kaolinite, which formed hydrogen-bond interactions with the carbonyl of CAP such that the hydrolysis activation energy of CAP was greatly reduced. Neither the Brønsted nor the Lewis acidity was the determinant for the hydrolysis reaction. The surface moisture content played an essential role in CAP hydrolysis. Specifically, water facilitated the mass transfer of CAP over the low-RH range, whereas excessive water competed for the reactive hydroxyl sites. These results highlight an important but long-overlooked abiotic transformation pathway for antibiotics in field soil, where the soil moisture is low and the microbial activity is suppressed.
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Affiliation(s)
- Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Dingding Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Jingyi Ling
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Chao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
| | - Cun Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science , Chinese Academy of Sciences , Nanjing 210008 , China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing 210023 , China
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Zaranyika MF, Dzomba P. Dissipation of chlortetracycline in the aquatic environment: Characterization in terms of a generalized multiphase pseudo–zero‐order rate law. INT J CHEM KINET 2019. [DOI: 10.1002/kin.21311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mark F. Zaranyika
- Chemistry DepartmentFaculty of scienceUniversity of Zimbabwe Harare Zimbabwe
| | - Pamhidzai Dzomba
- Chemistry DepartmentFaculty of scienceUniversity of Zimbabwe Harare Zimbabwe
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Su L, Caywood LM, Sivey JD, Dai N. Sunlight Photolysis of Safener Benoxacor and Herbicide Metolachlor as Mixtures on Simulated Soil Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6784-6793. [PMID: 31132254 DOI: 10.1021/acs.est.9b01243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Benoxacor is a safener paired with the high-use herbicide S-metolachlor. Commercial formulations containing both compounds are sprayed onto soil pre-emergence to enhance yields of corn. In this study, we evaluated the sunlight photolysis of metolachlor and benoxacor, individually and as mixtures, in three different reaction environments: in water and on two soil-simulating surfaces (quartz and kaolinite). When irradiated individually, benoxacor degraded at least 19 times faster than metolachlor in each reaction environment, consistent with its higher molar absorptivity within the solar spectrum than metolachlor. When metolachlor and benoxacor were irradiated as mixtures, benoxacor promoted metolachlor degradation on quartz and, to a lesser extent, in water, but not on kaolinite. On quartz, at a benoxacor/metolachlor molar ratio of 0.1:1, metolachlor degraded 1.8 times faster than in the absence of benoxacor; as the benoxacor/metolachlor ratio increased, metolachlor degradation rate also increased. The photolysis rate of benoxacor depended on its initial surface concentration and was promoted by metolachlor. Benoxacor photoproducts were capable of absorbing sunlight and serving as photosensitizers for metolachlor degradation. These results illustrate how a safener can influence the photochemistry of its coformulated herbicide and suggest that such mixture effects should be considered when evaluating the environmental fate of agrochemicals.
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Affiliation(s)
- Lei Su
- Department of Civil, Structural and Environmental Engineering , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
| | - Leandra M Caywood
- Department of Chemical and Materials Engineering , University of Alabama in Huntsville , Huntsville , Alabama 35899 , United States
| | - John D Sivey
- Department of Chemistry , Towson University , Towson , Maryland 21252 , United States
| | - Ning Dai
- Department of Civil, Structural and Environmental Engineering , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
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6
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Xu L, Li H, Mitch WA, Tao S, Zhu D. Enhanced Phototransformation of Tetracycline at Smectite Clay Surfaces under Simulated Sunlight via a Lewis-Base Catalyzed Alkalization Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:710-718. [PMID: 30561992 DOI: 10.1021/acs.est.8b06068] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
As an important class of soil minerals and a key constituent of colloidal particles in surface aquifers, smectite clays can strongly retain tetracyclines due to their large surface areas and high cation exchange capacities. However, the research on phototransformation of tetracyclines at smectite clay surfaces is rarely studied. Here, the phototransformation kinetics of tetracycline preadsorbed on two model smectite clays (hectorite and montmorillonite) exchanged with Na+, K+, or Ca2+ suspended in aqueous solution under simulated sunlight was compared with that of tetracycline dissolved in water using batch experiments. Adsorption on clays accelerated tetracycline phototransformation (half-lives shortened by 1.1-5.3 times), with the most significant effects observed for Na+-exchanged clays. Regardless of the presence or absence of clay, the phototransformation of tetracycline was facilitated by increasing pH from 4 to 7. Inhibition or enhancement of photolysis-induced reactive species combined with their measurement using scavenger/probe chemicals indicate that the facilitated production of self-photosensitized singlet oxygen (1O2) was the key factor contributing to the clay-enhanced phototransformation of tetracycline. As evidenced by the red shifts and the increased molar absorptivity in the UV-vis absorption spectra, the complexation of tetracycline with the negatively charged (Lewis base) sites on clay siloxane surfaces led to formation of the alkalized form, which has larger light absorption rate and is more readily to be oxidized compared to tetracycline in aqueous solution at equivalent pH. Our findings indicate a previously unrecognized, important phototransformation mechanism of tetracyclines catalyzed by smectite clays.
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Affiliation(s)
- Liangpang Xu
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes , Peking University , Beijing 100871 , China
| | - Hui Li
- Department of Plant, Soil, and Microbial Sciences , Michigan State University , East Lansing , Michigan 48824 , United States
| | - William A Mitch
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| | - Shu Tao
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes , Peking University , Beijing 100871 , China
| | - Dongqiang Zhu
- School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes , Peking University , Beijing 100871 , China
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Kerrigan JF, Sandberg KD, Engstrom DR, LaPara TM, Arnold WA. Sedimentary record of antibiotic accumulation in Minnesota Lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:970-979. [PMID: 29074236 DOI: 10.1016/j.scitotenv.2017.10.130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/13/2017] [Accepted: 10/13/2017] [Indexed: 05/22/2023]
Abstract
The widespread detection of antibiotics in the environment is concerning because antibiotics are designed to be effective at small doses. The objective of this work was to quantify the accumulation rates of antibiotics used by humans and animals, spanning several major antibiotic classes (sulfonamides, tetracyclines, fluoroquinolones, and macrolides), in Minnesota lake-sediment cores. Our goal was to determine temporal trends, the major anthropogenic source to these lacustrine systems, and the importance of natural production. A historical record of usage trends for ten human and/or animal-use antibiotics (four sulfonamides, three fluoroquinolones, one macrolide, trimethoprim, and lincomycin) was faithfully captured in the sediment cores. Nine other antibiotics were not detected. Ofloxacin, trimethoprim, sulfapyridine, and sulfamethazine were detected in all of the anthropogenically-impacted studied lakes. Maximum sediment fluxes reached 20.5ngcm-2yr-1 (concentration 66.1ng/g) for ofloxacin, 1.2ngcm-2yr-1 (1.2ng/g) for trimethoprim, 3.3ngcm-2yr-1 (11.3ng/g) for sulfapyridine, and 1.0ngcm-2yr-1 (1.6ng/g) for sulfamethazine, respectively. Natural production of lincomycin may have occurred in one lake at fluxes ranging from 0.4 to 1.8ngcm-2yr-1 (0.1 to 5.8ng/g). Wastewater effluent appears to be the primary source of antibiotics in the studied lakes, with lesser inputs from agricultural activities.
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Affiliation(s)
- Jill F Kerrigan
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, MN 55455, United States
| | - Kyle D Sandberg
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, MN 55455, United States
| | - Daniel R Engstrom
- St. Croix Watershed Research Station, Science Museum of Minnesota, 16910 152nd Street North, Marine on St. Croix, MN 55047, United States
| | - Timothy M LaPara
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, MN 55455, United States
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Dr. SE, Minneapolis, MN 55455, United States.
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Leng Y, Bao J, Song D, Li J, Ye M, Li X. Background Nutrients Affect the Biotransformation of Tetracycline by Stenotrophomonas maltophilia as Revealed by Genomics and Proteomics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10476-10484. [PMID: 28837770 DOI: 10.1021/acs.est.7b02579] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Certain bacteria are resistant to antibiotics and can even transform antibiotics in the environment. It is unclear how the molecular mechanisms underlying the resistance and biotransformation processes vary under different environmental conditions. The objective of this study is to investigate the molecular mechanisms of tetracycline resistance and biotransformation by Stenotrophomonas maltophilia strain DT1 under various background nutrient conditions. Strain DT1 was exposed to tetracycline for 7 days with four background nutrient conditions: no background (NB), peptone (P), peptone plus citrate (PC), and peptone plus glucose (PG). The biotransformation rate follows the order of PC > P > PG > NB ≈ 0. Genomic analysis showed that strain DT1 contained tet(X1), a gene encoding an FAD-binding monooxygenase, and eight peroxidase genes that could be relevant to tetracycline biotransformation. Quantitative proteomic analyses revealed that nodulation protein transported tetracycline outside of cells; hypoxanthine-guanine phosphoribosyltransferase facilitated the activation of the ribosomal protection proteins to prevent the binding of tetracycline to the ribosome and superoxide dismutase and peroxiredoxin-modified tetracycline molecules. Comparing different nutrient conditions showed that the biotransformation rates of tetracycline were positively correlated with the expression levels of superoxide dismutase.
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Affiliation(s)
- Yifei Leng
- Department of Civil Engineering, University of Nebraska , Lincoln, Nebraska 68588, United States
- School of Environment Studies, China University of Geosciences , Wuhan 430074, P. R. China
| | - Jianguo Bao
- School of Environment Studies, China University of Geosciences , Wuhan 430074, P. R. China
| | - Dandan Song
- School of Environment Studies, China University of Geosciences , Wuhan 430074, P. R. China
| | - Jing Li
- School of Environment Studies, China University of Geosciences , Wuhan 430074, P. R. China
| | - Mao Ye
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences , Nanjing 210008, P. R. China
| | - Xu Li
- Department of Civil Engineering, University of Nebraska , Lincoln, Nebraska 68588, United States
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10
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Yan S, Song W. Photo-transformation of pharmaceutically active compounds in the aqueous environment: a review. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2014; 16:697-720. [PMID: 24608883 DOI: 10.1039/c3em00502j] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In the past few years, the fate and transportation of pharmaceutically active compounds (PhACs) in aqueous environments have raised significant concerns among the public, scientists and regulatory groups. Photodegradation is an important removal process in surface waters. This review summarizes the last 10 years (2003-2013) of studies on the solar or solar-simulated photodegradation of PhACs in aqueous environments. The PhACs covered include: beta-blockers, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), histamine H₂-receptor antagonists, lipid regulators, carbamazepine, steroid hormones, and X-ray contrast media compounds. Kinetic studies, degradation mechanisms and toxicity removal are the three major topics involved in this review. The quantum yield for the direct photolysis of PhACs and the bimolecular reaction rate constants of PhACs with reactive oxygen species (ROS), such as the ˙OH radical and singlet oxygen, are also summarized. This information is not only important to predict the PhAC photodegradation fate, but also is very useful for advanced treatment technologies, such as ozone or advanced oxidation processes.
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Affiliation(s)
- Shuwen Yan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, P. R. China.
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Joy SR, Bartelt-Hunt SL, Snow DD, Gilley JE, Woodbury BL, Parker DB, Marx DB, Li X. Fate and transport of antimicrobials and antimicrobial resistance genes in soil and runoff following land application of swine manure slurry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:12081-12088. [PMID: 24044357 DOI: 10.1021/es4026358] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Due to the use of antimicrobials in livestock production, residual antimicrobials and antimicrobial resistance genes (ARGs) could enter the environment following the land application of animal wastes and could further contaminate surface and groundwater. The objective of this study was to determine the effect of various manure land application methods on the fate and transport of antimicrobials and ARGs in soil and runoff following land application of swine manure slurry. Swine manure slurries were obtained from facilities housing pigs that were fed chlortetracyline, tylosin or bacitracin and were land applied via broadcast, incorporation, and injection methods. Three rainfall simulation tests were then performed on amended and control plots. Results show that land application methods had no statistically significant effect on the aqueous concentrations of antimicrobials in runoff. However, among the three application methods tested broadcast resulted in the highest total mass loading of antimicrobials in runoff from the three rainfall simulation tests. The aqueous concentrations of chlortetracyline and tylosin in runoff decreased in consecutive rainfall events, although the trend was only statistically significant for tylosin. For ARGs, broadcast resulted in significantly higher erm genes in runoff than did incorporation and injection methods. In soil, the effects of land application methods on the fate of antimicrobials in top soil were compound specific. No clear trend was observed in the ARG levels in soil, likely because different host cells may respond differently to the soil environments created by various land application methods.
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Affiliation(s)
- Stacey R Joy
- Department of Civil Engineering, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
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Wang Y, Xu J, Li J, Wu F. Natural montmorillonite induced photooxidation of As(III) in aqueous suspensions: roles and sources of hydroxyl and hydroperoxyl/superoxide radicals. JOURNAL OF HAZARDOUS MATERIALS 2013; 260:255-262. [PMID: 23770489 DOI: 10.1016/j.jhazmat.2013.05.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Revised: 05/09/2013] [Accepted: 05/15/2013] [Indexed: 06/02/2023]
Abstract
Photooxidation of arsenite(As(III)) in a suspension of natural montmorillonite under the irradiation of metal halide lamp (λ ≥ 313 nm)has been investigated. The results showed that the natural montmorillonite induced the photooxidation of As(III) by generating hydroxyl radicals (HO·) and hydroperoxyl/superoxide radicals (HO₂·/O₂⁻·). HO· which was responsible for the As(III) photooxidation. Approximately 38% of HO· was generated by the photolysis of ferric ions, and the formation of the remaining 62% was strongly dependent on the HO₂·/O₂⁻·. The presence of free ironions (Fe(2+) and Fe(3+)), made significant contributions to the photogeneration of these reactive oxygen species (ROS). The photooxidation of As(III) in natural montmorillonite suspensions was greatly influenced by the pH values. The photooxidation of As(III) by natural montmorillonite followed the Langmuir-Hinshelwood equation. In addition, the photooxidation of As(III) could be enhanced by the addition of humic acid. This work demonstrates that photooxidation may be an important environmental process for the oxidation of As(III) and may be a way to remove As(III) from acidic surface water containing iron-bearing clay minerals.
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Affiliation(s)
- Yajie Wang
- Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, 430079, PR China
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Pharmaceuticals in the Built and Natural Water Environment of the United States. WATER 2013. [DOI: 10.3390/w5031346] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kang HJ, Lim MY, Kwon JH. Effects of adsorption onto silica sand particles on the hydrolysis of tetracycline antibiotics. ACTA ACUST UNITED AC 2012; 14:1853-9. [DOI: 10.1039/c2em10961a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chen Y, Li H, Wang Z, Tao T, Wei D, Hu C. Photolysis of chlortetracycline in aqueous solution: kinetics, toxicity and products. J Environ Sci (China) 2012; 24:254-260. [PMID: 22655385 DOI: 10.1016/s1001-0742(11)60775-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The aqueous photodegradation of the widely used antibiotic chlortetracycline (CTC) was investigated under simulated sunlight. The quantum yield of photodegradation increased from 3.3 x 10(-4) to 8.5 x 10(-3) within the pH range of 6.0 to 9.0. The presence of Ca2+, Fe3+, and NO(-3) enhanced the photodegradation of CTC, whereas Mg2+, Mn2+, and Zn2+ inhibited the degradation with the order Mn2+ > Zn2+ > Mg2+ at pH 7.3. The monovalent cations (Na+ and K+) had negligible effect on the photolysis of CTC. Fulvic acid (FA) decreased the photodegradation of CTC due to light screening effect. Hydrogen peroxide (H2O2) was formed concurrently with direct photodegradation of CTC. The generation rate of H2O2 increased from 0.027 to 0.086 micromol/(L x min) when the pH ranged from 6.0 to 9.0. The CTC solution was about three-fold more toxic to the Photobacterium phosphoreum bacteria after irradiation, suggesting that the photoproducts and H2O2 formed in the CTC solution exhibited high risk on the bacteria. By LC-ESI(+)-MS, the photoproducts of CTC were identified. The direct photodegradation of CTC was involved in hydroxylation and N-demethyl/dedismethyl processes. The main photoproducts included the iso-CTC analog containing hydroxyl groups (m/z 511.4 and 495.4), and the N-demethyl/dedismethyl products of the photoproduct m/z 495.4 (m/z 481.3 and 467.4). In addition, the photochemical dechlorination of CTC led to tetracycline (m/z 445.5).
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Affiliation(s)
- Yong Chen
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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