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Mundi AP, Santoke H. Photodegradation of tylosin tartrate by advanced oxidation processes. Photochem Photobiol Sci 2024:10.1007/s43630-024-00621-7. [PMID: 39217268 DOI: 10.1007/s43630-024-00621-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
Tylosin tartrate, a macrolide antibiotic, is one of a class of emerging contaminants that have been detected in natural bodies of water since they are not easily removed by conventional treatment processes. In this study, the direct and indirect photodegradation of tylosin tartrate was analyzed to understand the role of reactive oxygen species and organic matter that may be present in surface waters. While direct photolysis caused negligible degradation (k = (9.4 ± 1.8) × 10-5 s-1), the addition of 0.4 M hydrogen peroxide (k = (2.18 ± 0.01) × 10-4 s-1) or usage of the photo-Fenton process (k = (2.96 ± 0.02) × 10-4 s-1) resulted in greater degradation. The degradation was maximized by combining tylosin tartrate with an experimentally determined optimal concentration of humic acid (15 mg/L), which readily produced singlet oxygen and increased the overall degradation (k = 1.31 ± 0.05) × 10-3 s-1) by means of indirect photolysis. Absolute pseudo-first-order bimolecular reaction rate constants for tylosin tartrate were measured with singlet oxygen [(4.7936 ± 0.0001) × 105 M-1 s-1] and hydroxyl radical [(5.2693 ± 0.0002) × 109 M-1 s-1] using competition kinetics, and when combined with data on concentration of the reactive oxygen species, showed that the hydroxyl radical makes a contribution to the degradation that is approximately eleven orders of magnitude greater than singlet oxygen.
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Affiliation(s)
- Arsh P Mundi
- Department of Chemistry and Biochemistry, California State University, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA
| | - Hanoz Santoke
- Department of Chemistry and Biochemistry, California State University, 9001 Stockdale Highway, Bakersfield, CA, 93311, USA.
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Xu Y, Zhang Y, Wang X, Wang Z, Huang L, Wu H, Ren J, Gu C, Chen Z. Enhanced photodegradation of tylosin in the presence of natural montmorillonite: Synergistic effects of adsorption and surface hydroxyl radicals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158750. [PMID: 36108839 DOI: 10.1016/j.scitotenv.2022.158750] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/14/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
Tylosin (TYL) is a ubiquitous macrolide antibiotic which has been frequently detected in natural aqueous environment. Montmorillonite (MMT), a major component of natural suspended particles, plays essential roles in the transportation and transformation processes of various organic contaminants. This study systematically investigated the photodegradation behavior and mechanism of TYL in MMT suspensions under simulated sunlight irradiation. In the existence of 0.1 g L-1 Na-MMT, >80.8 % TYL was degraded after 8 h irradiation, which was significantly higher than that in the absence of MMT (42.5 %). Further mechanistic studies suggested that the synergistic effects including the formation of surface complex and the generation of surface hydroxyl radicals play essential roles in the accelerated TYL phototransformation. Meanwhile, other factors like exchangeable cations of MMTs, pH and ionic strength could also strongly influence the TYL photodegradation. The probable degradation pathways of TYL in MMT suspension was further proposed based on the detected intermediates and DFT calculations. Photobacterium phospherium T3 bioluminescent assay revealed that the photodegradation products of TYL have a lower acute toxicity than bulk TYL, especially in the presence of MMT. This study provides new insights for the photodegradation pathways of organic contaminants in aqueous environments, which is of great importance for assessing the fate and risk of emerging pollutants in natural surface water bodies.
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Affiliation(s)
- Yichen Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; Technology Innovation Center for Ecological Monitoring & Restoration Project on Land (arable), Ministry of Natural Resources Geological Survey of Jiangsu Province, Nanjing 210018, PR China
| | - Yutong Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Zhe Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Liuqing Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Jinghua Ren
- Technology Innovation Center for Ecological Monitoring & Restoration Project on Land (arable), Ministry of Natural Resources Geological Survey of Jiangsu Province, Nanjing 210018, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; Technology Innovation Center for Ecological Monitoring & Restoration Project on Land (arable), Ministry of Natural Resources Geological Survey of Jiangsu Province, Nanjing 210018, PR China
| | - Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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