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Ge L, Li X, Zhang S, Cao S, Zheng J, Wang D, Zhang P. Comparing the photodegradation of typical antibiotics in ice and in water: Degradation kinetics, mechanisms, and effects of dissolved substances. CHEMOSPHERE 2024; 352:141489. [PMID: 38368963 DOI: 10.1016/j.chemosphere.2024.141489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 02/04/2024] [Accepted: 02/15/2024] [Indexed: 02/20/2024]
Abstract
New antibiotic contaminants have been detected in both surface waters and natural ice across cold regions. However, few studies have revealed distinctions between their ice and aqueous photochemistry. In this study, the photodegradation and effects of the main dissolved substances on the photolytic kinetics were investigated for sulfonamides (SAs) and fluoroquinolones (FQs) in ice/water under simulated sunlight. The results showed that the photolysis of sulfamethizole (SMT), sulfachloropyridazine (SCP), enrofloxacin (ENR) and difloxacin (DIF) in ice/water followed the pseudo-first-order kinetics with their quantum yields ranging from 4.93 × 10-3 to 11.15 × 10-2. The individual antibiotics experienced disparate photodegradation rates in ice and in water. This divergence was attributed to the concentration-enhancing effect and the solvent cage effect that occurred in the freezing process. Moreover, the main constituents (Cl-, HASS, NO3- and Fe(III)) exhibited varying degrees of promotion or inhibition on the photodegradation of SAs and FQs in the two phases (p < 0.05), and these effects were dependent on the individual antibiotics and the matrix. Extrapolation of the laboratory data to the field conditions provided a reasonable estimate of environmental photolytic half-lives (t1/2,E) during midsummer and midwinter in cold regions. The estimated t1/2,E values ranged from 0.02 h for ENR to 14 h for SCP, which depended on the reaction phases, latitudes and seasons. These results revealed the similarities and differences between the ice and aqueous photochemistry of antibiotics, which is important for the accurate assessment of the fate and risk of these new pollutants in cold environments.
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Affiliation(s)
- Linke Ge
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China; Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
| | - Xuanyan Li
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Shuang Zhang
- School of Environmental Science and Technology, Dalian Maritime University, Dalian, 116026, PR China
| | - Shengkai Cao
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
| | - Jinshuai Zheng
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Degao Wang
- School of Environmental Science and Technology, Dalian Maritime University, Dalian, 116026, PR China
| | - Peng Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China.
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Sun H, Chen T, Zhang L, Dong D, Li Y, Guo Z. Distribution of florfenicol and norfloxacin in ice during water freezing process: Dual effects by fluorine substituents. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:119921. [PMID: 35973450 DOI: 10.1016/j.envpol.2022.119921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/16/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Distribution in ice is regarded as one of important transport modes for pollutants in seasonal freeze-up waters in cold regions. However, the distribution characteristics and mechanisms of fluorinated antibiotics as emerging contaminants during the water freezing process remain unclear. Here, florfenicol and norfloxacin were selected as model fluorinated antibiotics to investigate their ice-water distribution. Effects of antibiotic molecular structure on the distribution were explored through comparative studies with their non-fluorinated structural analogs. Results showed that phase changes during the ice growth process redistributed the antibiotics, with antibiotic concentrations in water 3.0-6.4 times higher than those in ice. The solute-rich boundary layer with a concentration gradient was presented at the ice-water interface and controlled by constitutional supercooling during the freezing process. The ice-water distribution coefficient (KIW) values of antibiotics increased by 34.8%-38.0% with a doubling of the cooling area. The solute distribution coefficient (Kbs) values of antibiotics at -20 °C were 65.6%-70.3% higher than at -10 °C. The KIW and Kbs values of all antibiotics were negatively correlated with their water solubilities. The fluorine substituents influenced the binding energies between antibiotics and ice, resulting in a 1.1-fold increase in the binding energy of norfloxacin on the ice surface relative to its structural analog pipemidic acid. The results provide a new insight into the transport behaviors of fluorinated pharmaceuticals in ice-water systems.
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Affiliation(s)
- Heyang Sun
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Tianyi Chen
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China; Housing and Urban-Rural Construction Bureau of Chengde High-Tech Industrial Development Zone, Chengde, 067000, China
| | - Liwen Zhang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Deming Dong
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Yanchun Li
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, China
| | - Zhiyong Guo
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China.
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Li Z, Dong D, Zhang L, Li Y, Guo Z. Effect of fulvic acid concentration levels on the cleavage of piperazinyl and defluorination of ciprofloxacin photodegradation in ice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119499. [PMID: 35597482 DOI: 10.1016/j.envpol.2022.119499] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 05/03/2022] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
Ice is an important physical and chemical sink for various pollutants in cold regions. The photodegradation of emerging fluoroquinolone (FQ) antibiotic contaminants with dissolved organic matter (DOM) in ice remains poorly understood. Here, the photodegradation of ciprofloxacin (CIP) and fulvic acid (FA) in different proportions as representative FQ and DOM in ice were investigated. Results suggested that the photodegradation rate constant of CIP in ice was 1.9 times higher than that in water. When CFA/CCIP ≤ 60, promotion was caused by FA sensitization. FA increased the formation rate of cleavage in the piperazine ring and defluorination products. When 60 < CFA/CCIP < 650, the effect of FA on CIP changed from promoting to inhibiting. When 650 ≤ CFA/CCIP ≤ 2600, inhibition was caused by both quenching effects of 143.9%-51.3% and light screening effects of 0%-48.7%. FA inhibited cleavage in the piperazine ring for CIP by the scavenging reaction intermediate of aniline radical cation in ice. When CFA/CCIP > 2600, the light screening effect was greater than the quenching effect. This work provides new insights into how DOM affects the FQ photodegradation with different concentration proportions, which is beneficial for understanding the environmental behaviors of fluorinated pharmaceuticals in cold regions.
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Affiliation(s)
- Zhuojuan Li
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Deming Dong
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Liwen Zhang
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China
| | - Yanchun Li
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, China
| | - Zhiyong Guo
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin Provincial Key Laboratory of Water Resources and Environment, College of New Energy and Environment, Jilin University, Changchun, 130012, China.
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