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1.
Environ Res ; 251(Pt 1): 118650, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38458586

RESUMO

The ferrihydrite-catalyzed heterogeneous photo-Fenton reaction shows great potential for environmental remediation of fluoroquinolone (FQs) antibiotics. The degradation of enoxacin, a model of FQ antibiotics, was studied by a batch experiment and theoretical calculation. The results revealed that the degradation efficiency of enoxacin reached 89.7% at pH 3. The hydroxyl radical (∙OH) had a significant impact on the degradation process, with a cumulative concentration of 43.9 µmol L-1 at pH 3. Photogenerated holes and electrons participated in the generation of ∙OH. Eleven degradation products of enoxacin were identified, with the main degradation pathways being defluorination, quinolone ring and piperazine ring cleavage and oxidation. These findings indicate that the ferrihydrite-catalyzed photo-Fenton process is a valid way for treating water contaminated with FQ antibiotics.


Assuntos
Enoxacino , Compostos Férricos , Peróxido de Hidrogênio , Ferro , Poluentes Químicos da Água , Compostos Férricos/química , Poluentes Químicos da Água/química , Ferro/química , Enoxacino/química , Catálise , Peróxido de Hidrogênio/química , Antibacterianos/química
2.
Sci Total Environ ; 923: 171376, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38432388

RESUMO

Seasonal freezing of waters occurs during winter in cold regions. Bromate ( [Formula: see text] ) is a disinfection by-product generated during water treatment, its interaction with emerging contaminants may be affected by freezing. Nitrite ( [Formula: see text] ) is widely distributed in the environment, whereas its effect on the interaction of emerging contaminants and [Formula: see text] in ice may have been overlooked. Herein carbamazepine (CBZ) was selected as a model emerging contaminant to elucidate the role of reactive nitrogen species (RNS) in contaminant transformation during the reduction of [Formula: see text] by [Formula: see text] in ice. Results indicated that freezing significantly enhanced CBZ degradation by [Formula: see text] . The CBZ degradation by [Formula: see text] and [Formula: see text] in ice was 25.4 %-27.8 % higher than that by [Formula: see text] . Contributions of hydroxyl radical (•OH), bromine radical (•Br), and RNS to CBZ degradation in freezing/dark or sunlight systems were 8.1 % or 15.9 %, 25.4 % or 7.2 %, and 66.5 % or 76.9 %, respectively. Most CBZ was degraded by RNS generated during the reduction of [Formula: see text] by [Formula: see text] in ice, resulting in 16.4 % of transformation products being nitro-containing byproducts. Hybrid toxicity of CBZ/ [Formula: see text] / [Formula: see text] system was reduced effectively after the freezing-sunlight process. This study can provide new insights into the environmental fate of emerging contaminants, [Formula: see text] , and [Formula: see text] in cold regions.

3.
Sci Total Environ ; 913: 169797, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38181939

RESUMO

Ferrihydrite acts as a natural reservoir for nutrient elements, organic matter, and coexisting pollutants through adsorption and coprecipitation. However, the degradation of emerging fluoroquinolone antibiotics during the transformation of ferrihydrite coprecipitates, especially those with various dissociated species, remains insufficiently explored. In this study, Enoxacin (ENO), employed as a model antibiotic, was introduced to prepare ferrihydrite-ENO coprecipitates. The influence of coprecipitated ENO on the transformation of the ferrihydrite-ENO coprecipitate was investigated across different pH conditions. The results revealed that ferrihydrite-ENO coprecipitates thermodynamically transformed into more stable goethite and/or hematite under all pH conditions. In neutral and alkaline conditions, ENO promoted the transformation of coprecipitates into goethite while hindering hematite formation. Conversely, under acidic conditions, ENO directly obstructed the transformation of coprecipitates into hematite. Different dissociated species of ENO displayed distinct degradation pathways. The cationic form of ENO exhibited a greater tendency for hydroxylation and defluorination, while the zwitterion form leaned toward piperazine ring oxidation, with limited preference for quinolone ring oxidation. The anionic form of ENO exhibited the fastest degradation rate. It is essential to emphasize that the toxicity of the degradation products was intricately connected to the specific reaction sites and the functional groups they acquired post-oxidation. These findings offer fresh insights into the role of antibiotics in coprecipitation, the transformation of ferrihydrite coprecipitates, and the fate of coexisting antibiotics.


Assuntos
Antibacterianos , Enoxacino , Compostos de Ferro , Compostos Férricos , Minerais , Oxirredução
4.
J Hazard Mater ; 466: 133533, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38286046

RESUMO

Antibiotic resistance poses a global environmental challenge that jeopardizes human health and ecosystem stability. Antibiotic resistant bacteria (ARB) significantly promote the spreading and diffusion of antibiotic resistance. This study investigated the efficiency and mechanism of inactivating tetracycline-resistant Escherichia coli (TR E. coli) using Fe3O4 @MoS2 activated persulfate (Fe3O4 @MoS2/PS). Under optimized conditions (200 mg/L Fe3O4 @MoS2, 4 mM PS, 35 °C), TR E. coli (∼7.5 log CFU/mL) could be fully inactivated within 20 min. The primary reactive oxygen species (ROS) responsible for TR E. coli inactivation in the Fe3O4 @MoS2/PS system were hydroxyl radicals (•OH) and superoxide radicals (•O2-). Remarkably, the efflux pump protein was targeted and damaged by the generated ROS during the inactivation process, resulting in cell membrane rupture and efflux of cell content. Additionally, the horizontal transmission ability of residual antibiotic resistance genes (ARGs) harboring in the TR E. coli was also reduced after the inactivation treatment. This study offers an efficient approach for TR E. coli inactivation and substantial mitigation of antibiotic resistance dissemination risk.


Assuntos
Antibacterianos , Escherichia coli , Humanos , Antibacterianos/farmacologia , Escherichia coli/genética , Molibdênio , Espécies Reativas de Oxigênio , Ecossistema , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Bactérias/genética , Tetraciclina , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123841, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38241933

RESUMO

Due to the very important role in physiological process, a simple and sensitive hemin detection method is necessarily required. Biomass-based carbonized polymer dots (CPDs) have been widely studied especially as fluorescence probe owing to the advantages of low toxicity and the variety of fluorescence color, yet there are still challenges in developing their multi-color emission property from the same raw materials. In this work, red, white and blue emissive CPDs derived from chlorophyll have been synthesized via hydrothermal method. Then white-emitted CPDs (white-CPDs) with the Commission International d'Eclairage (CIE) coordinates at (0.34, 0.32) were used to develop a fluorescence quenched sensing system for hemin determination. There is a good linear relationship between (F0-F)/F0 and concentration of hemin in the range of 0.1-0.95 µM with a detection limit of 0.043 µM, and the quenching mechanism was considered to be caused by inner filter effect (IFE). Moreover, it has been successfully used for hemin detection in serum and also for visual determination, which indicating great potential in applications of disease diagnoses and trace identification.


Assuntos
Pontos Quânticos , Hemina , Polímeros , Corantes Fluorescentes , Espectrometria de Fluorescência/métodos , Carbono
6.
J Hazard Mater ; 458: 132063, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37463559

RESUMO

Ice formation in reservoirs could promote the accumulation of antibiotics in fish, potentially leading to elevated concentrations in fish muscles, kidneys, and livers. However, for the seasonal ice-sealed reservoirs, antibiotic sampling and detecting conditions in water and fish are normally limited by the ice cover. Additionally, previous studies on the prediction of antibiotics accumulated in seasonal ice-sealed reservoir fish are scarce. This study presents a coupled model incorporating a multimedia fate model and a bioaccumulation model to predict antibiotic fate in water and the muscles, kidneys, and livers of fish in seasonal ice-sealed reservoirs. Prediction concentrations of florfenicol were higher than those of ofloxacin and norfloxacin in both water and fish from the seasonal ice-sealed reservoir. Log bioaccumulation factors of antibiotics in Cyprinus carpio and Hypophthalmichthys nobilis in January 2021 were higher than those in October 2020 by 21.5% and 12.6%, respectively. Antibiotics mean transfer fluxes from water to fish muscles, kidneys, and livers increased owing to the reservoir ice-cover formation date advancing by 13.0%, 77.1%, and 61.0%, respectively. This work provides a modeling tool for investigating the fate and mass transfer flux of antibiotics in biological and environmental phases in seasonal ice-sealed reservoirs.


Assuntos
Carpas , Poluentes Químicos da Água , Animais , Água , Fluoroquinolonas , Gelo , Bioacumulação , Multimídia , Estações do Ano , Antibacterianos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental
7.
Toxics ; 11(7)2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37505569

RESUMO

Over the past few decades, acetaminophen (ACT), a typical nonsteroidal anti-inflammatory drug (NSAID), has gained global usage, positioning itself as one of the most extensively consumed medications. However, the incomplete metabolism of ACT leads to a substantial discharge into the environment, classifying it as an environmental contaminant with detrimental effects on non-target organisms. Various wastewater treatment technologies have been developed for ACT removal to mitigate its potential environmental risk. Particularly, photocatalytic technology has garnered significant attention as it exhibits high efficiency in oxidizing and degrading a wide range of organic pollutants. This comprehensive review aims to systematically examine and discuss the application of photocatalytic technology for the removal of ACT from aqueous environments. Additionally, the study provides a detailed overview of the limitations associated with the photocatalytic degradation of ACT in practical applications, along with effective strategies to address these challenges.

8.
Chemosphere ; 338: 139524, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37467849

RESUMO

Water, sediments, and biofilms are the typical microbial carriers in natural water environments. However, comparative analysis of the distribution of bacterial and fungal communities in different carriers within the same habitat is relatively lacking. Therefore, this study employed 16 S and ITS rRNA gene sequencing to identify bacterial and fungal community structures in water, sediments, and biofilm. The results show that (1) the OTUs numbers revealed that the bacterial abundance, at the levels of species, genus, and family, followed the order of sediments > water > biofilms, while the fungal abundance order was water > sediments > biofilms. In addition, bacteria were mainly present in sediments, while fungi were mainly present in water. (2) The α diversity index (Shannon, ACE, Simpson, and Chao1) order, for bacteria was: sediments > water > biofilms, indicating that the diversity and homogeneity of bacteria in sediments were relatively higher; for fungi was: water > sediments > biofilms, indicating that the diversity and abundance of fungi in water were high. (3) The core phylum of bacterial in the water, sediments, and biofilms was Cyanobacteria (31.3-46.1%) and Actinobacteria (27.6-36.1%); Proteobacteria (35.0-41.8%), Cyanobacteria (14.7-36.6%); and Proteobacteria (63.3-69.2%), respectively. (4) The mainly colonized fungal phyla in biofilms in the water, sediments, and biofilms were Basidiomycota (29.3-38.7%) and Ascomycota (16.2-27.7%); Zygomycota (13.1-17.5%), Basidiomycota (5.6-17.6%); and Zygomycota (23.8-44.2%). (5) There were significant species differences in bacterial and fungal communities in water, sediments, and biofilm by NMDS analysis. Findings are useful for guiding significance for the Biogeochemical cycle of elements, the environmental fate of pollutants, and the study of water ecosystems.


Assuntos
Ascomicetos , Cianobactérias , Água , Ecossistema , Rios , Biofilmes , Fungos/genética , China , Sedimentos Geológicos/química
9.
Sci Total Environ ; 894: 165014, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37343881

RESUMO

Ice plays a crucial role in contaminant transformation in seasonally ice-covered waters. In this study, the characteristics and mechanisms of an emerging contaminant oxcarbazepine (OXC) degradation by a disinfection by-product bromate ( [Formula: see text] ) in ice were explored via combined experiments and theoretical calculations. Results showed that 74.0 % and 86.4 % of OXC was degraded by [Formula: see text] in ice after 140 min in dark and 120 min under solar irradiation, respectively, while the reaction was negligible in water. The oxidation-reduction potential of [Formula: see text] solution at 1000 µmol L-1 was 56.9 % higher than that at 50 µmol L-1. The oxidation-reduction potential of [Formula: see text] solution at pH 2 was 14.8 %-109.5 % higher than those at other pH values. Enhanced OXC degradation by [Formula: see text] in ice could be attributed to increased [Formula: see text] oxidation capacity resulting from locally elevated [Formula: see text] and H+ concentrations. Hypobromous acid (HOBr), •OH, and Br• generated by direct photolysis under solar irradiation further promoted the OXC degradation in ice. Br• formed by the direct photolysis of accumulated HOBr under solar irradiation caused the generation of bromine-containing degradation products. Bromine-containing degradation products possessed higher potential toxicities, which could contribute to increase the secondary pollution of water environment.

10.
J Hazard Mater ; 457: 131793, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37302190

RESUMO

Ice is a crucial medium in cold regions and plays an important role in the transformation of pollutants. When waters receiving treated wastewater freeze in cold regions during winter, the emerging contaminant carbamazepine (CBZ) and the disinfection by-product bromate ( [Formula: see text] ) can coexist in ice. However, their interaction in ice remains poorly understood. Here, CBZ degradation by [Formula: see text] in ice was investigated via a simulation experiment. Results showed that 96% of CBZ was degraded by [Formula: see text] after 90 min in ice in dark, while the degradation was negligible in water. The time required for nearly 100% CBZ degradation by [Formula: see text] in ice under solar irradiation was 22.2% shorter than in dark. The production of hypobromous acid (HOBr) was responsible for the gradually accelerated CBZ degradation rate in ice. The HOBr generation time in ice under solar irradiation was 50% shorter than in dark. The formation of HOBr and hydroxyl radical by the direct photolysis of [Formula: see text] under solar irradiation enhanced the CBZ degradation in ice. CBZ was mainly degraded by deamidation, decarbonylation, decarboxylation, hydroxylation, molecular rearrangement, and oxidation reactions. Furthermore, 18.5% of degradation products exhibited lower toxicity than their parent CBZ. This work can provide new insights into the environmental behaviors and fate of emerging contaminants in cold regions.

11.
Anal Chem ; 95(20): 7863-7871, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37159270

RESUMO

Understanding the metabolic disorders induced by nano- and microplastics in aquatic organisms at the molecular level could help us understand the potential toxicity of nano- and microplastics more thoroughly and provide a fundamental scientific basis for regulating the usage and management of plastic products. In this research, the effect of polypropylene nanoplastics (PP-NPs) and microplastics (PP-MPs) on metabolites in the tilapia liver was comprehensively investigated by internal extractive electrospray ionization mass spectrometry (iEESI-MS). A partial least-squares discriminant analysis (PLS-DA) and a one-component analysis of variance (ANOVA) were used for selecting 46 differential metabolites, including phospholipids, amino acids, peptides, carbohydrates, alkaloids, purines, pyrimidines, and nucleosides. Pathway enrichment analysis showed significant effects on glycerophospholipid metabolism, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis after tilapia were exposed to PP-N/MPs. Dysregulation of these metabolites is mainly reflected in the possible induction of hepatitis, oxidative stress, and other symptoms. The application of iEESI-MS technology without sample pretreatment to the study of metabolic disorders in aquatic organisms under the interference of nano- and microplastics provides a promising analytical method for environmental toxicology research.


Assuntos
Ciclídeos , Tilápia , Poluentes Químicos da Água , Animais , Microplásticos , Espectrometria de Massas por Ionização por Electrospray/métodos , Plásticos , Polipropilenos/toxicidade , Fígado , Organismos Aquáticos , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/metabolismo
12.
J Hazard Mater ; 448: 130951, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-36860039

RESUMO

Residual antibiotics in wastewater threaten living organisms and the ecosystem, while the photocatalytic process is recognized as one of the most eco-friendly and promising technologies for the treatment of antibiotic wastewater. In this study, a novel Z-scheme Ag3PO4/1T@2H-MoS2 heterojunction was synthesized, characterized, and used for the visible-light-driven photocatalytic degradation of tetracycline hydrochloride (TCH). It was found that Ag3PO4/1T@2H-MoS2 dosage and coexisting anions had significant effects on the degradation efficiency, which could reach up to 98.9 % within 10 min under the optimal condition. Combing experiments and theoretical calculations, the degradation pathway and mechanism were thoroughly investigated. The excellent photocatalytic property of Ag3PO4/1T@2H-MoS2 was achieved attributed to the Z-scheme heterojunction structure, which remarkably inhibited the recombination of photoinduced electrons and holes. The potential toxicity and mutagenicity for TCH and generated intermediates were evaluated, which revealed the ecological toxicity of antibiotic wastewater was reduced effectively during the photocatalytic degradation process.


Assuntos
Molibdênio , Tetraciclina , Ecossistema , Águas Residuárias , Antibacterianos
13.
Environ Pollut ; 323: 121299, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36804883

RESUMO

Seasonally ice-covered reservoirs have both freeze-thaw and artificial regulation characteristics which could cause the accumulation of antibiotics. Florfenicol, one of the most widely used veterinary antibiotics, with an environmental persistence due to its fluorinated substituents has been detected in the suburban drinking water source reservoirs. In this study, a four-level fugacity model that is appropriate for ice-water-sediment systems was developed to predict the fate of florfenicol and assess its ecological risk in seasonally ice-covered reservoirs. The effects of freeze-thaw and artificial regulation processes on the volume variation of ice and water were considered by the model. The simulation accuracies in ice and water in the model were improved by 3.9% and 17.7%, respectively, compared with the traditional model. The results of mass transfer analysis showed that the inflow of florfenicol in tributaries and the volume variation of ice and water were the major factors influencing the concentration variation of florfenicol in the seasonally ice-covered reservoir. Additionally, ecological risk analysis showed that the values of risk quotients ranged from 0.019 to 0.038 which was consistently at a low ecological risk level. Our findings provide a modeling tool for predicting the fate of antibiotics with persistence and assessing their ecological risks in seasonally freeze-thaw reservoirs in cold regions.


Assuntos
Água Potável , Poluentes Químicos da Água , Multimídia , Antibacterianos/toxicidade , Antibacterianos/análise , Camada de Gelo , Água Potável/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise
14.
Sci Total Environ ; 857(Pt 2): 159469, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36265615

RESUMO

Antibiotics are prevalent in the aquatic environment as emerging contaminants. Their knowledge of seasonal ice-sealed reservoirs, however, is limited. The occurrence, temporal variation, and prioritization of twenty-three antibiotics in Shitoukoumen Reservoir during its ice-free and ice-sealed periods, as well as the source apportionment of the high-priority antibiotics, were investigated in this study. The results showed that florfenicol was the dominant antibiotic in Shitoukoumen Reservoir, with different median concentrations of 75.0 ± 6.5 ng L-1 and 7.0 ± 1.7 ng kg-1 in the water and ice, respectively. The concentrations of florfenicol, sulfaguanidine, and sulfamonomethoxine in the water of the reservoir water varied over time, but their monthly mass loads from inflow rivers were similar during ice-free and ice-sealed periods. This indicated that other factors, such as aquacultural practice, non-point source rain runoff, and the blocking effect of ice, determined the temporal variations of the three antibiotics and resulted in their relatively high concentrations during the ice-free period. High-priority antibiotics included erythromycin, florfenicol, ofloxacin, sarafloxacin, sulfaquinoxaline, thiamphenicol, and tylosin. Aquaculture was the primary source of high-priority antibiotics, accounting for 67.3 % and 59.4 % of the total high-priority antibiotic concentrations during ice-free and ice-sealed periods, respectively. The findings suggest that aquaculture, rain runoff, and ice blocking should all be considered as factors influencing antibiotic variations in a seasonal ice-sealed reservoir.


Assuntos
Antibacterianos , Poluentes Químicos da Água , Antibacterianos/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Estações do Ano , Rios , Água , China
15.
Analyst ; 147(19): 4399, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36093871

RESUMO

Correction for 'Direct analysis of metabolites in the liver tissue of zebrafish exposed to fiproles by internal extractive electrospray ionization mass spectrometry' by Jun Liu et al., Analyst, 2021, 146, 4480-4486, https://doi.org/10.1039/D1AN00490E.

16.
Analyst ; 147(17): 3930-3937, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35920668

RESUMO

Direct profiling of endogenous biomolecules in tissue samples is considered as a promising approach to investigate metabolic-related toxicity in organisms induced by emerging pollutants. Herein, we report the application of internal extractive electrospray ionization mass spectrometry (iEESI-MS) to direct phospholipid profiling in the liver and spleen tissues of Nile tilapia exposed to perfluorooctanoic acid (PFOA). Combining positive and negative ion detection modes, 130 phospholipid signals were directly detected and identified by iEESI-MS in the tissues of Nile tilapia, including phosphatidyl cholines (PCs), sphingomyelins (SMs), phosphatidic acids (PAs), phosphatidyl ethanolamines (PEs), phosphatidyl glycerols (PGs), phosphatidyl inositols (PIs) and phosphatidyl serines (PSs). With the help of partial least squares discriminant analysis (PLS-DA) and one-way analysis of variance (ANOVA), several phospholipid signals showed a significant difference in the tissue of Nile tilapia between the control group and PFOA exposure groups. In addition, pathway analysis revealed that PFOA has a significant metabolic impact on the glycerophospholipid metabolism in Nile tilapia. Without complex sample preparation, iEESI-MS was applied to direct phospholipid profiling in the liver and spleen tissues of Nile tilapia treated with PFOA, which provided a promising methodology for investigating environmental toxicity and phospholipid-dysregulation caused by emerging pollutants in aquatic organisms.


Assuntos
Ciclídeos , Poluentes Ambientais , Animais , Caprilatos , Fluorocarbonos , Ácidos Fosfatídicos , Espectrometria de Massas por Ionização por Electrospray/métodos
17.
Environ Pollut ; 311: 119921, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35973450

RESUMO

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.


Assuntos
Gelo , Norfloxacino , Antibacterianos , Flúor , Congelamento , Tianfenicol/análogos & derivados
18.
Environ Pollut ; 307: 119499, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35597482

RESUMO

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.


Assuntos
Ciprofloxacina , Poluentes Químicos da Água , Benzopiranos , Substâncias Húmicas/análise , Gelo/análise , Fotólise , Piperazinas
19.
Ecotoxicol Environ Saf ; 239: 113646, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35588620

RESUMO

Heavy metals often coexist in contaminated environmental media, and competition between heavy metals for adsorption sites influences the absorption capacity of biochar. In this study, the adsorption mechanism of pyrolytically modified wood ear mushroom sticks (250, 450, and 650 °C) as a new bio-adsorbent for single-ion and mixed-ion solutions Cd2+ and Pb2+ Biochar adsorption experiments showed that the adsorption abilities of Cd2+ and Pb2+ increased with increasing WMBC (wood ear mushroom sticks biochar) pyrolysis temperature. According to the Langmuir model, the maximum adsorption capacity of Cd2+ and Pb2+increased with higher pyrolysis temperature, being 29.84, 39.08, 46.16 mg·g-1and 124.3, 186.8, 234.2 mg·g-1, respectively for three different pyrolysis temperatures 250, 450, and 650 °C. WMBC exhibited a stronger adsorption ability for Pb2+ than for Cd2+. Competition between the two heavy metals severely inhibited the adsorption of Cd2+. Based on X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and Fourier transform infrared spectroscopy (FTIR) analyses, the dominant interaction mechanisms were determined to be complexation, ion exchange, precipitation, and C-π interaction. The results suggest WMBC shows promise as a novel, cheap, and effective adsorbent that can be used to remove both Cd2+ and Pb2+ pollutants from environmental media.


Assuntos
Agaricales , Metais Pesados , Poluentes Químicos da Água , Adsorção , Auricularia , Cádmio/análise , Carvão Vegetal/química , Íons , Cinética , Chumbo , Metais Pesados/química , Temperatura , Poluentes Químicos da Água/análise
20.
Sci Total Environ ; 821: 153354, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35085643

RESUMO

Antibiotics are increasingly detected in fish caught in ice-free waters, but information on fish caught in ice-sealed waters is insufficient. The concentrations of 23 antibiotics in the gills, muscles, kidneys, livers, biles, and brains of Cyprinus carpio and Hypophthalmichthys nobilis caught during winter fish-hunting activities in Chagan Lake, Haernao Reservoir, and Shitoukoumen Reservoir were systematically studied to ascertain the variations among fish species and fishing regions, tissue distribution, and bioaccumulation, as well as the potential risk to humans via the consumption of contaminated fish. The results indicated that the individual antibiotic concentration in tissues ranged from undetectable to 35.0 ng/g ww. The total antibiotic concentration in fish muscles from Shitoukoumen Reservoir was lower than that from Chagan Lake and Haernao Reservoir, but showed no significant difference between Cyprinus carpio and Hypophthalmichthys nobilis. Chloramphenicols had a high proportion in most fish tissues ranging from 28.3% to 44.0%, and the antibiotics were mainly distributed in the livers with a total concentration of 54.8 ± 9.9 ng/g ww. The mean values of bioaccumulation factors (BAF) of antibiotics in tissues ranged from 79.4 to 1000 L/kg, with the higher values found in the fish livers. The hazard quotient and hazard index value of antibiotics in the muscles of fish from ice-sealed were less than 1, indicating a negligible risk to human health via the consumption of fish muscles. This study revealed that the total antibiotic concentration in muscles showed spatial variations but not fish species-dependence. The antibiotics mainly accumulated in the livers. In addition, the target antibiotic concentrations in the muscles of fish from ice-sealed waters met the safe for consumption criteria.


Assuntos
Carpas , Poluentes Químicos da Água , Animais , Antibacterianos/análise , Bioacumulação , Monitoramento Ambiental , Peixes , Humanos , Distribuição Tecidual , Poluentes Químicos da Água/análise
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