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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.
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
3.
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
4.
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.

5.
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
6.
Analyst ; 146(14): 4480-4486, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34160503

RESUMO

Exploring the metabolic disturbance of fipronil and its derivatives in aquatic organisms may provide a more comprehensive understanding of the impact of fipronil on the ecological environment. In this work, internal extractive electrospray ionization mass spectrometry (iEESI-MS) was used to directly analyze metabolites in the liver tissue of zebrafish exposed to fipronil and its three derivatives. Partial least squares-discriminant analysis (PLS-DA) revealed that 32 signals were considered as differential signals in zebrafish after the exposure treatment of fipronil and its derivatives, including phosphatidylcholines (PCs), lysophosphatidylcholines (LPCs), phosphatidylethanolamines (PEs), fatty acids and so on. The pathway analysis result showed that both fipronil and its derivatives have a significant impact on the glycerophospholipid metabolism of zebrafish. Besides, the intensities of PC signals in the liver samples of each group showed such a trend: mixed fiprole exposed group > fipronil sulfone exposed group ≈ fipronil sulfide exposed group > fipronil exposed group > fipronil desulfinyl exposed group > control group, indicating that mixed exposure of fipronil and its derivatives exhibited more significant metabolic disturbance in zebrafish. Taken together, iEESI-MS is applied to environmental toxicology and investigating the metabolic disturbance induced by fipronil and its derivatives in aquatic organisms, providing a new analytical method for this field.


Assuntos
Inseticidas , Peixe-Zebra , Animais , Inseticidas/análise , Fígado/química , Espectrometria de Massas por Ionização por Electrospray
7.
Artigo em Inglês | MEDLINE | ID: mdl-29902118

RESUMO

The occurrence, spatial distribution, seasonal variation, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in overlying water and surface sediments from Tiaozi River, which is an urban river running through the downtown of Siping City, a traditional industrial city of northeastern China, were investigated. The total PAH concentrations (ΣPAHs) in water varied from 473.5 to 2674.3 ng/L with a mean value of 1272.6 ng/L and ranged from 601.5 to 2906.3 ng/g with a mean value of 1534.4 ng/g in sediments. Both the individual and total PAH concentrations in water and sediments decreased from upstream to downstream, and the average ΣPAHs between the four seasons in water and sediments decreased in the following order of winter> autumn> spring> summer. The composition of the PAHs was characterized by an abundance of PAHs from 2 rings to 4 rings, and the predominant components were naphthalene, chrysene, and benzo(a)anthracene. The identification of the source indicated that coal combustion could be the main contributor to the PAHs. The equivalent toxic concentrations of benzo[a]pyrene in the water ranged from 11.5 to 33.1 ng/L, which were much higher than the concentration limit, suggesting that PAHs in the water could cause potential risks. The risk assessment of PAHs in sediments also showed that PAHs could cause negative effects on aquatic organisms in this river.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Rios/química , Poluentes Químicos da Água/análise , Organismos Aquáticos/química , China , Cidades , Carvão Mineral/análise , Geografia , Sedimentos Geológicos/química , Humanos , Indústrias
8.
Water Sci Technol ; 75(11-12): 2538-2545, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28617272

RESUMO

Ammonia nitrogen (NH4-N) contaminated wastewater has posed a great threat to the safety of water resources. In this study, air stripping was employed to remove and recover NH4-N from acetylene purification wastewater (APW) in a polyvinylchloride manufacturing plant. Investigated parameters were initial APW pH, air flow rate, APW temperature and stripping time. The NH4-N removal by air stripping has been modeled and the overall volumetric mass transfer coefficient (KLa) of the stripping process has been calculated from the model equation obtained. In addition, the ability of H2SO4 solution to absorb the NH3 stripped was also investigated. The results indicated that under the experimental conditions, the APW temperature and its initial pH had significant effects on the NH4-N removal efficiency and the KLa, while the effects of other factors were relatively minor. The removal efficiency and residual concentration of NH4-N were about 91% and 12 mg/L, respectively, at the optimal operating conditions of initial APW pH of 12.0, air flow rate of 0.500 m3/(h·L), APW temperature of 60 °C and stripping time of 120 min. One volume of H2SO4 solution (0.2 mol/L) could absorb about 93% of the NH3 stripped from 54 volumes of the APW.


Assuntos
Amônia/análise , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Acetileno/química , Resíduos Industriais , Águas Residuárias/química
9.
Water Sci Technol ; 74(2): 508-15, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27438257

RESUMO

Acetylene purification wastewater (APW) usually contains high concentrations of ammonia nitrogen (NH4-N), which is generated during the production of acetylene in a polyvinylchloride manufacturing plant. In this study, a struvite precipitation method was selected to remove NH4-N from the APW. Laboratory-scale batch experiments were performed to investigate the effects of the initial APW pH, phosphate (PO4(3-)) concentration, magnesium (Mg(2+)) concentration, and sources of PO4(3-) and Mg(2+) on NH4-N removal. The results indicated that the initial APW pH had a significant effect on the removal of NH4-N, while the other factors had relatively minor effect. The NH4-N could be effectively removed at an optimum initial APW pH of 9.5, when Na2HPO4·12H2O and MgSO4·7H2O were both applied to NH4-N at a ratio of 1.2. Under these conditions, the efficiency of removal of NH4-N, total nitrogen and chemical oxygen demand were 85%, 84% and 18%, respectively. The X-ray diffraction analysis indicated that the precipitates were dominated by struvite. The scanning electron microscopy analysis of the precipitates showed a typical morphology of stick-like and prismatic crystals with coarse surface. The energy dispersive spectroscopy analysis indicated that the precipitates contained P, O, Mg and Ca.


Assuntos
Amônia/metabolismo , Estruvita/química , Águas Residuárias/análise , Acetileno , Precipitação Química , Desnitrificação , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Magnésio/análise , Fosfatos/análise , Cloreto de Polivinila
10.
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.

11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
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.

18.
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.

19.
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.

20.
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
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