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1.
PLoS One ; 19(4): e0300021, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635818

RESUMO

Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas' disease, a parasitic infection responsible for significant morbidity and mortality in Latin America. The current treatments have many serious drawbacks and new drugs are urgently required. In the UK, T. cruzi is classified by the Advisory Committee on Dangerous Pathogens (ACDP) as a Hazard Group 3 organism and strict safety practices must be adhered to when handling this pathogen in the laboratory. Validated inactivation techniques are required for safe T. cruzi waste disposal and removal from Containment Level 3 (CL3) facilities for storage, transportation and experimental analysis. Here we assess three T. cruzi. inactivation methods. These include three freeze-thaw cycles, chemical inactivation with Virkon disinfectant, and air drying on Whatman FTA cards (A, B, C, Elute) and on a Mitra microsampling device. After each treatment parasite growth was monitored for 4-6 weeks by microscopic examination. Three freeze-thaw cycles were sufficient to inactivate all T. cruzi CLBrener Luc life cycle stages and Silvio x10/7 A1 large epimastigote cell pellets up to two grams wet weight. Virkon treatment for one hour inactivated T. cruzi Silvio x10/7 subclone A1 and CLBrener Luc both in whole blood and cell culture medium when incubated at a final concentration of 2.5% Virkon, or at ≥1% Virkon when in tenfold excess of sample volume. Air drying also inactivated T. cruzi CLBrener Luc spiked blood when dried on FTA A, B or Elute cards for ≥30 minutes and on a Mitra Microsampler for two hours. However, T. cruzi CLBrener Luc were not inactivated on FTA C cards when dried for up to two hours. These experimentally confirmed conditions provide three validated T. cruzi inactivation methods which can be applied to other related ACDP Hazard Group 2-3 kinetoplastid parasites.


Assuntos
Aminopiridinas , Doença de Chagas , Ácidos Sulfúricos , Trypanosoma cruzi , Humanos , Doença de Chagas/parasitologia , Peróxidos
2.
Environ Sci Technol ; 58(15): 6564-6574, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38578220

RESUMO

Formation of highly oxygenated molecules (HOMs) such as organic peroxides (ROOR, ROOH, and H2O2) is known to degrade food and organic matter. Gas-phase unimolecular autoxidation and bimolecular RO2 + HO2/RO2 reactions are prominently renowned mechanisms associated with the formation of peroxides. However, the reaction pathways and conditions favoring the generation of peroxides in the aqueous phase need to be evaluated. Here, we identified bulk aqueous-phase ROOHs in varying organic precursors, including a laboratory model compound and monoterpene oxidation products. Our results show that formation of ROOHs is suppressed at enhanced oxidant concentrations but exhibits complex trends at elevated precursor concentrations. Furthermore, we observed an exponential increase in the yield of ROOHs when UV light with longer wavelengths was used in the experiment, comparing UVA, UVB, and UVC. Water-soluble organic compounds represent a significant fraction of ambient cloud-water components (up to 500 µM). Thus, the reaction pathways facilitating the formation of HOMs (i.e., ROOHs) during the aqueous-phase oxidation of water-soluble species add to the climate and health burden of atmospheric particulate matter.


Assuntos
Peróxido de Hidrogênio , Peróxidos , Material Particulado/análise , Oxidantes , Água , Aerossóis
3.
Water Sci Technol ; 89(7): 1682-1700, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38619897

RESUMO

In this research, ascorbic acid (AA) was used to enhance Fe(II)/Fe(III)-activated permonosulfate (PMS) systems for the degradation of fluoranthene (FLT). AA enhanced the production of ROS in both PMS/Fe(II) and PMS/Fe(III) systems through chelation and reduction and thus improved the degradation performance of FLT. The optimal molar ratio in PMS/Fe(II)/AA/FLT and PMS/Fe(III)/AA/FLT processes were 2/2/4/1 and 5/10/5/1, respectively. In addition, the experimental results on the effect of FLT degradation under different groundwater matrixes indicated that PMS/Fe(III)/AA system was more adaptable to different water quality conditions than the PMS/Fe(II)/AA system. SO4·- was the major reactive oxygen species (ROS) responsible for FLT removal through the probe and scavenging tests in both systems. Furthermore, the degradation intermediates of FLT were analyzed using gas chromatograph-mass spectrometry (GC-MS), and the probable degradation pathways of FLT degradation were proposed. In addition, the removal of FLT was also tested in actual groundwater and the results showed that by increasing the dose and pre-adjusting the solution pH, 88.8 and 100% of the FLT was removed for PMS/Fe(II)/AA and PMS/Fe(III)/AA systems. The above experimental results demonstrated that PMS/Fe(II)/AA and PMS/Fe(III)/AA processes have a great perspective in practice for the rehabilitation of FLT-polluted groundwater.


Assuntos
Compostos Férricos , Fluorenos , Poluentes Químicos da Água , Espécies Reativas de Oxigênio , Poluentes Químicos da Água/química , Peróxidos/química , Compostos Ferrosos
4.
Int J Mol Sci ; 25(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38612811

RESUMO

In most cases, the unused by-products of venison, including deer tallow, are disposed of in rendering plants. Deer tallow contains essential fatty acids and can be used to prepare products for everyday food and advanced applications. This work aimed to process deer tallow into hydrolyzed products using microbial lipases. A Taguchi design with three process factors at three levels was used to optimize the processing: amount of water (8, 16, 24%), amount of enzyme (2, 4, 6%), and reaction time (2, 4, 6 h). The conversion of the tallow to hydrolyzed products was expressed by the degree of hydrolysis. The oxidative stability of the prepared products was determined by the peroxide value and the free fatty acids by the acid value; further, color change, textural properties (hardness, spreadability, stickiness, and adhesiveness), and changes at the molecular level were observed by Fourier transform infrared spectroscopy (FTIR). The degree of hydrolysis was 11.8-49.6%; the peroxide value ranged from 12.3 to 29.5 µval/g, and the color change of the samples expressed by the change in the total color difference (∆E*) was 1.9-13.5. The conditions of enzymatic hydrolysis strongly influenced the textural properties: hardness 25-50 N, spreadability 20-40 N/s, and stickiness < 0.06 N. FTIR showed that there are changes at the molecular level manifested by a decrease in ester bonds. Enzymatically hydrolyzed deer tallow is suitable for preparing cosmetics and pharmaceutical matrices.


Assuntos
Cervos , Gorduras , Animais , Hidrólise , Carne , Peróxidos
5.
J Hazard Mater ; 470: 134254, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38615644

RESUMO

The existence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) has been a global public environment and health issue. Due to the different cell structures, gram-positive/negative ARB exhibit various inactivation mechanisms in water disinfection. In this study, a gram-negative ARB Escherichia coli DH5α (E. coli DH5α) was used as a horizontal gene transfer (HGT) donor, while a gram-positive ARB Bacillus as a recipient. To develop an efficient and engineering applicable method in water disinfection, ARB and ARGs removal efficiency of Fe(VI) coupled peroxydisulfate (PDS) or peroxymonosulfate (PMS) was compared, wherein hydroxylamine (HA) was added as a reducing agent. The results indicated that Fe(VI)/PMS/HA showed higher disinfection efficiency than Fe(VI)/PDS/HA. When the concentration of each Fe(VI), PMS, HA was 0.48 mM, 5.15 log E. coli DH5α and 3.57 log Bacillus lost cultivability, while the proportion of recovered cells was 0.0017 % and 0.0566 %, respectively, and HGT was blocked. Intracellular tetA was reduced by 2.49 log. Fe(IV) and/or Fe(V) were proved to be the decisive reactive species. Due to the superiority of low cost as well as high efficiency and practicality, Fe(VI)/PMS/HA has significant application potential in ARB, ARGs removal and HGT inhibition, offering a new insight for wastewater treatment.


Assuntos
Transferência Genética Horizontal , Ferro , Peróxidos , Peróxidos/química , Ferro/química , Purificação da Água/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Farmacorresistência Bacteriana/genética , Desinfecção/métodos , Sulfatos/química , Antibacterianos/farmacologia , Antibacterianos/química , Bacillus/genética , Bacillus/efeitos dos fármacos , Bacillus/metabolismo
6.
Mol Biol Evol ; 41(4)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38573174

RESUMO

Transcriptomic analyses across large scales of evolutionary distance have great potential to shed light on regulatory evolution but are complicated by difficulties in establishing orthology and limited availability of accessible software. We introduce here a method and a graphical user interface wrapper, called Annotator-RNAtor, for performing interspecies transcriptomic analysis and studying intragenus evolution. The pipeline uses third-party software to infer homologous genes in various species and highlight differences in the expression of the core-genes. To illustrate the methodology and demonstrate its usefulness, we focus on the emergence of the highly virulent Leptospira subclade known as P1+, which includes the causative agents of leptospirosis. Here, we expand on the genomic study through the comparison of transcriptomes between species from P1+ and their related P1- counterparts (low-virulent pathogens). In doing so, we shed light on differentially expressed pathways and focused on describing a specific example of adaptation based on a differential expression of PerRA-controlled genes. We showed that P1+ species exhibit higher expression of the katE gene, a well-known virulence determinant in pathogenic Leptospira species correlated with greater tolerance to peroxide. Switching PerRA alleles between P1+ and P1- species demonstrated that the lower repression of katE and greater tolerance to peroxide in P1+ species was solely controlled by PerRA and partly caused by a PerRA amino-acid permutation. Overall, these results demonstrate the strategic fit of the methodology and its ability to decipher adaptive transcriptomic changes, not observable by comparative genome analysis, that may have been implicated in the emergence of these pathogens.


Assuntos
Leptospira , Leptospirose , Leptospira/genética , Leptospirose/genética , Estresse Oxidativo/genética , Peróxidos , Perfilação da Expressão Gênica
7.
Sci Total Environ ; 927: 172159, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38575032

RESUMO

Sediment contamination by heavy metals is a pressing environmental concern. While in situ metal stabilization techniques have shown promise, a great challenge remains in the simultaneous immobilization of multi-metals co-existing in contaminated sediments. This study aims to address this challenge by developing a practical method for stabilizing multi-metals by hydroxyapatite and calcium peroxide (HAP/CaO2) dosing strategies. Results showed that dosing 15.12 g of HAP/CaO2 at a ratio of 3:1 effectively transformed labile metals into stable fractions, reaching reaction kinetic equilibrium within one month with a pseudo-second-order kinetic (R2 > 0.98). The stable fractions of Nickel (Ni), Chromium (Cr), and lead (Pb) increased by approximately 16.9 %, 26.7 %, and 21.9 %, respectively, reducing heavy metal mobility and ensuring leachable concentrations complied with the stringent environmental Class I standard. Mechanistic analysis indicated that HAP played a crucial role in Pb stabilization, exhibiting a high rate of 0.0176 d-1, while Cr and Ni stabilization primarily occurred through the formation of hydroxide precipitates, as well as the slowly elevated pH (>8.5). Importantly, the proposed strategy poses a minimal environmental risk to benthic organisms exhibits almost negligible toxicity towards Vibrio fischeri and the Chironomus riparius, and saves about 71 % of costs compared to kaolinite. These advantages suggest the feasibility of HAP/CaO2 dosing strategies in multi-metal stabilization in contaminated sediments.


Assuntos
Durapatita , Peróxidos , Poluentes Químicos da Água , Durapatita/química , Poluentes Químicos da Água/análise , Peróxidos/química , Metais Pesados , Sedimentos Geológicos/química , Recuperação e Remediação Ambiental/métodos
8.
Sci Total Environ ; 927: 172270, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38583627

RESUMO

Recent studies show that greenhouse gas (GHG) emissions from urban landscape water are significant and cannot be overlooked, underscoring the need to develop effective strategies for mitigating GHG production from global freshwater systems. Calcium peroxide (CaO2) is commonly used as an eco-friendly reagent for controlling eutrophication in water bodies, but whether CaO2 can reduce GHG emissions remains unclear. This study investigated the effects of CaO2 dosage on the production of methane (CH4) and nitrous oxide (N2O) in urban landscape water under anoxic conditions during summer. The findings reveal that CaO2 addition not only improved the physicochemical and organoleptic properties of simulated urban landscape water but also reduced N2O production by inhibiting the activity of denitrifying bacteria across various dosages. Moreover, CaO2 exhibited selective effects on methanogens. Specifically, the abundance of acetoclastic methanogen Methanosaeta and methylotrophic methanogen Candidatus_Methanofastidiosum increased whereas the abundance of the hydrogenotrophic methanogen Methanoregula decreased at low, medium, and high dosages, leading to higher CH4 production at increased CaO2 dosage. A comprehensive multi-objective evaluation indicated that an optimal dosage of 60 g CaO2/m2 achieved 41.21 % and 84.40 % reductions in CH4 and N2O production, respectively, over a 50-day period compared to the control. This paper not only introduces a novel approach for controlling the production of GHGs, such as CH4 and N2O, from urban landscape water but also suggests a methodology for optimizing CaO2 dosage, providing valuable insights for its practical application.


Assuntos
Metano , Óxido Nitroso , Peróxidos , Qualidade da Água , Metano/análise , Óxido Nitroso/análise , Peróxidos/análise , Poluentes Químicos da Água/análise , Gases de Efeito Estufa/análise
9.
Molecules ; 29(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38611805

RESUMO

Cobalt-nitrogen co-doped carbon nanotubes (Co3@NCNT-800) were synthesized via a facile and economical approach to investigate the efficient degradation of organic pollutants in aqueous environments. This material demonstrated high catalytic efficiency in the degradation of carbamazepine (CBZ) in the presence of peroxymonosulfate (PMS). The experimental data revealed that at a neutral pH of 7 and an initial CBZ concentration of 20 mg/L, the application of Co3@NCNT-800 at 0.2 g/L facilitated a degradation rate of 64.7% within 60 min. Mechanistic investigations indicated that the presence of pyridinic nitrogen and cobalt species enhanced the generation of reactive oxygen species. Radical scavenging assays and electron spin resonance spectroscopy confirmed that radical and nonradical pathways contributed to CBZ degradation, with the nonradical mechanism being predominant. This research presents the development of a novel PMS catalyst, synthesized through an efficient and stable method, which provides a cost-effective solution for the remediation of organic contaminants in water.


Assuntos
Nanotubos de Carbono , Peróxidos , Benzodiazepinas , Carbamazepina , Cobalto , Nitrogênio , Água
10.
ACS Nano ; 18(15): 10542-10556, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38561324

RESUMO

Immunotherapy has emerged as a potential approach for breast cancer treatment. However, the rigid stromal microenvironment and low immunogenicity of breast tumors strongly reduce sensitivity to immunotherapy. To sensitize patients to breast cancer immunotherapy, hyaluronic acid-modified zinc peroxide-iron nanocomposites (Fe-ZnO2@HA, abbreviated FZOH) were synthesized to remodel the stromal microenvironment and increase tumor immunogenicity. The constructed FZOH spontaneously generated highly oxidative hydroxyl radicals (·OH) that degrade hyaluronic acid (HA) in the tumor extracellular matrix (ECM), thereby reshaping the tumor stromal microenvironment and enhancing blood perfusion, drug penetration, and immune cell infiltration. Furthermore, FZOH not only triggers pyroptosis through the activation of the caspase-1/GSDMD-dependent pathway but also induces ferroptosis through various mechanisms, including increasing the levels of Fe2+ in the intracellular iron pool, downregulating the expression of FPN1 to inhibit iron efflux, and activating the p53 signaling pathway to cause the failure of the SLC7A11-GSH-GPX4 signaling axis. Upon treatment with FZOH, 4T1 cancer cells undergo both ferroptosis and pyroptosis, exhibiting a strong immunogenic response. The remodeling of the tumor stromal microenvironment and the immunogenic response of the cells induced by FZOH collectively compensate for the limitations of cancer immunotherapy and significantly enhance the antitumor immune response to the immune checkpoint inhibitor αPD-1. This study proposes a perspective for enhancing immune therapy for breast cancer.


Assuntos
Neoplasias da Mama , Neoplasias , Humanos , Feminino , Neoplasias da Mama/terapia , Ácido Hialurônico , Imunoterapia , Peróxidos , Zinco , Microambiente Tumoral , Linhagem Celular Tumoral
11.
J Colloid Interface Sci ; 665: 825-837, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38564946

RESUMO

Photocatalytic peroxymonosulfate (PMS) oxidation systems demonstrate significant potential and promising prospects through the interconnection of photocatalytic and PMS oxidation for simultaneously achieving efficient pollutant removal and reduction of PMS dosage, which prevents resource wastage and secondary pollution. In this study, a Z-scheme Bi25FeO40/BiOCl (BOFC) heterojunction was constructed to carry out the photocatalytic PMS oxidation process for tetracyclines (TCs) pollutants at low PMS concentrations (0.08 mM). The photocatalytic PMS oxidation rate of Bi25FeO40/BiOCl composites for tetracycline hydrochloride (TCH), chlortetracycline (CTC), oxytetracycline (OTC) and doxycycline (DXC) reaches 86.6%, 83.6%, 86.7%, and 88.0% within 120 min. Simultaneously, the BOFC/PMS system under visible light (Vis) equally displayed the practical application prospects for the solo and mixed simulated TCs antibiotics wastewater. Based on the electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) valence band spectrum, a Z-scheme electron migration pathway was proposed to elucidate the mechanism underlying the performance enhancement of BOFC composites. Bi25FeO40 in BOFC composites can serve as active site for activating PMS by the formation of Fe3+/Fe2+ cycle. Toxicity estimation software tool (T.E.S.T.) and mung beans planting experiment demonstrates that BOFC/PMS/Vis system can reduce toxicity of TCs wastewater. Therefore, BOFC/PMS/Vis system achieves efficient examination in different water environments and efficient utilization of PMS, which displays a scientific reference for achieving environmentally-friendly and resource-saving handling processes.


Assuntos
Poluentes Ambientais , Peróxidos , Águas Residuárias , Espécies Reativas de Oxigênio , Antibacterianos , Tetraciclina , Luz , Tetraciclinas , Oxigênio
12.
Anal Chem ; 96(10): 4213-4223, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38427460

RESUMO

The accurate quantification of cancer-derived exosomes, which are emerging as promising noninvasive biomarkers for liquid biopsies in the early diagnosis of cancer, is becoming increasingly imperative. In our work, we developed a magnetically controlled photothermal, colorimetric, and fluorescence trimode aptasensor for human gastric cancer cell (SGC-7901)-derived exosomes. This sensor relied on CP/Mn-PBA DSNBs nanocomposites, created by decorating copper peroxide (CP) nanodots on polyethyleneimine-modified manganese-containing Prussian blue analogues double-shelled nanoboxes (PEI-Mn-PBA DSNBs). Through self-assembly, we attached CD63 aptamer-labeled CP/Mn-PBA DSNBs (Apt-CP/Mn-PBA DSNBs) to complementary DNA-labeled magnetic beads (cDNA-MB). During exosome incubation, these aptamers preferentially formed complexes with exosomes, and we efficiently removed the released CP/Mn-PBA DSNBs by using magnetic separation. The CP/Mn-PBA DSNBs exhibited high photoreactivity and photothermal conversion efficiency under near-infrared (NIR) light, leading to temperature variations under 808 nm irradiation, correlating with different exosome concentrations. Additionally, colorimetric detection was achieved by monitoring the color change in a 3,3',5,5'-tetramethylbenzidine (TMB) system, facilitated by PEI modification, NIR-enhanced peroxidase-like activity of CP/Mn-PBA DSNBs and their capacity to generate Cu2+ and H2O2 under acidic conditions. Moreover, in the presence of Cu2+ and ascorbic acid (AA), DNA sequences could form dsDNA-templated copper nanoparticles (CuNPs), which emitted strong fluorescence at around 575 nm. Increasing exosome concentrations correlated with decreases in temperature, absorbance, and fluorescence intensity. This trimode biosensor demonstrated satisfactory ability in differentiating gastric cancer patients from healthy individuals using human serum samples.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Exossomos , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Cobre , Peróxidos , Peróxido de Hidrogênio , Colorimetria
13.
Molecules ; 29(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474614

RESUMO

The Selçuk district of Izmir is one of the most essential regions in terms of olive oil production. In this study, 60 olive oil samples were obtained from five different locations (ES: Eski Sirince Yolu, KK: Kinali Köprü, AU: Abu Hayat Üst, AA: Abu Hayat Alt, and DB: Degirmen Bogazi) in the Selçuk region of Izmir during two (2019-2020 and 2020-2021) consecutive cropping seasons. Quality indices (free acidity, peroxide value, p-Anisidine value, TOTOX, and spectral absorption at 232 and 270 nm) and the fatty acid, phenolic, and sterol profiles of the samples were determined to analyze the changes in the composition of Selcuk olive oils according to their growing areas. When the quality criteria were analyzed, it was observed that KK had the lowest FFA (0.11% oleic acid, PV (6.66 meq O2/kg), p-ANV (11.95 mmol/kg), TOTOX (25.28), and K232 (1.99) values and K270 had the highest value. During the assessment of phenolic profiles, the ES group exhibited the highest concentration of the phenolic compound p-HPEA-EDA (oleocanthal), with a content of 93.58 mg/kg, equivalent to tyrosol. Upon analyzing the fatty acid and sterol composition, it was noted that AU displayed the highest concentration of oleic acid (71.98%) and ß-sitosterol (87.65%). PCA analysis illustrated the distinct separation of the samples, revealing significant variations in both sterol and fatty acid methyl ester distributions among oils from different regions. Consequently, it was determined that VOOs originating from the Selçuk region exhibit distinct characteristics based on their geographical locations. Hence, this study holds great promise for the region to realize geographically labeled VOOs.


Assuntos
Olea , Ácido Oleico , Azeite de Oliva/análise , Ácidos Graxos , Peróxidos , Esteróis , Óleos de Plantas
14.
Molecules ; 29(5)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38474682

RESUMO

Nowadays, antibiotics are widely used, increasing the risk of contamination of the water body and further threatening human health. The traditional water treatment process is less efficient in degrading antibiotics, and the advanced oxidation process (AOPs) is cleaner and more efficient than the traditional biochemical degradation process. The combined ozone/peroxymonosulfate (PMS) advanced oxidation process (O3/PMS) based on sulfate radical (SO4•-) and hydroxyl radical (•OH) has developed rapidly in recent years. The O3/PMS process has become one of the most effective ways to treat antibiotic wastewater. The reaction mechanism of O3/PMS was reviewed in this paper, and the research and application progress of the O3/PMS process in the degradation of antibiotics in drinking water and wastewater effluent were evaluated. The operation characteristics and current application range of the process were summarized, which has a certain reference value for further research on O3/PMS process.


Assuntos
Água Potável , Ozônio , Poluentes Químicos da Água , Purificação da Água , Humanos , Águas Residuárias , Antibacterianos , Poluentes Químicos da Água/análise , Peróxidos , Oxirredução
15.
Environ Sci Pollut Res Int ; 31(18): 26773-26789, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38456975

RESUMO

In this study, CoCr layered double hydroxide material (CoCr-LDH) was prepared and used as an effective catalyst for peroxymonosulfate (PMS) activation to degrade organics in water. The prepared CoCr-LDH material had a crystalline structure and relatively porous structure, as determined by various surface analyses. In Rhodamine B (RhB) removal, the most outstanding PMS activation ability belongs to the material with a Co:Cr molar ratio of 2:1. The removal of RhB follows pseudo-first-order kinetics (R2 > 0.99) with an activation energy of 38.23 kJ/mol and efficiency of 98% after 7 min of treatment, and the total organic carbon of the solution reduced 47.2% after 10 min. The activation and oxidation mechanisms were proposed and the RhB degradation pathways were suggested with the key contribution of O2•- and 1O2. Notably, CoCr-LDH can activate PMS over a wide pH range of 4 - 9, and apply to a wide range of organic pollutants and aqueous environments. The material has high stability and good recovery, which can be reused for 5 cycles with a stable efficiency of above 88%, suggesting a high potential for practical recalcitrant water treatment via PMS activation by heterogeneous catalysts.


Assuntos
Peróxidos , Poluentes Químicos da Água , Purificação da Água , Poluentes Químicos da Água/química , Peróxidos/química , Purificação da Água/métodos , Rodaminas/química , Cinética , Oxirredução , Catálise
16.
Environ Sci Pollut Res Int ; 31(18): 26916-26927, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38456980

RESUMO

Catalytic wet peroxide oxidation (CWPO) has become an important deep oxidation technology for organics removal in wastewater treatments. Supported Cu-based catalysts belong to an important type of CWPO catalyst. In this paper, two Cu catalysts, namely, Cu/Al2O3-air and Cu/Al2O3-H2 were prepared and evaluated through catalytic degradation of phenol. It was found that Cu/Al2O3-H2 had an excellent catalytic performance (TOC removal rate reaching 96%) and less metal dissolution than the Cu/Al2O3-air case. Moreover, when the organic removal rate was promoted at a higher temperature, the metal dissolution amounts was decreased. Combined with hydroxyl radical quenching experiments, a catalytic oxidation mechanism was proposed to explain the above-mentioned interesting behaviors of the Cu/Al2O3-H2 catalyst for CWPO. The catalytic test results as well as the proposed mechanism can provide better guide for design and synthesis of good CWPO catalysts.


Assuntos
Cobre , Oxirredução , Peróxidos , Fenol , Catálise , Cobre/química , Peróxidos/química , Fenol/química , Óxido de Alumínio/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Eliminação de Resíduos Líquidos/métodos
17.
Environ Sci Pollut Res Int ; 31(17): 25751-25768, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38488915

RESUMO

The fabrication of low-cost, highly efficient, environmentally friendly, and easily separable metal-free heterogeneous catalysts for environmental remediation remains a challenge. In this study, granular nitrogen-doped highly developed porous carbons with a particle size of 0.25-0.30 mm were prepared by preoxidation and subsequent NH3 modification of a commercially available coconut-based activated carbon, and used to activate peroxymonosulphate (KHSO5) or hydrogen peroxide (H2O2) to degrade bisphenol A (BPA). The nitrogen-doped carbon (ACON-950) prepared by NH3 modification at 950 °C, with the addition of only 0.15 g/L could remove 100% of 50 mg/L BPA in 150 min, and more than 90% of the removed BPA was due to degradation. The removal rates of total organic carbon of ACON-950/KHSO5 and ACON-950/H2O2 systems reached 60.4% and 66.2% respectively, indicating the excellent catalytic activity of ACON-950. The reaction rate constant was significantly positively correlated with the absolute content of pyridinic N (N-6) and graphitic N (N-Q) and negatively and weakly positively correlated with pyrrolic N (N-5) and defects. Quenching experiments combined with electron paramagnetic resonance demonstrated that singlet oxygen was the dominant reactive oxidative species for BPA degradation. ACON-950 was characterized before and after the degradation reaction using N2 adsorption-desorption analyzer, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results confirmed the prominent contribution of both the N-6 and N-Q to the catalytic performance of nitrogen-doped carbons. The reusability of ACON-950 and its application in actual water bodies further demonstrated its remarkable potential for the remediation of organic pollutants in wastewater.


Assuntos
Compostos Benzidrílicos , Carvão Vegetal , Peróxido de Hidrogênio , Fenóis , Nitrogênio/química , Peróxidos/química , Metais
18.
Environ Pollut ; 348: 123861, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38537796

RESUMO

Sediments are important sinks for di-(2-ethylhexyl) phthalate (DEHP), a plasticizer, and thus, maintaining the sediment quality is essential for eliminating plasticizers in aqueous environments and recovering the sediment ecological functions. To mitigate the potential risks of endocrine-disrupting compounds, identifying an effective and eco-friendly degradation process of organic pollutants from sediments is important. However, sustainable and efficient utilization of slow pyrolysis for converting shark fishbone to generate shark fishbone biochar (SFBC) has rarely been explored. Herein, SFBC biomass was firstly produced by externally incorporating heteroatoms or iron oxide onto its surface in conjunction with peroxymonosulfate (PMS) to promote DEHP degradation and explore the associated benthic bacterial community composition from the sediment in the water column using the Fe-N-SFBC/PMS system. SFBC was pyrolyzed at 300-900 °C in aqueous sediment using a carbon-advanced oxidation process (CAOP) system based on PMS. SFBC was rationally modified via N or Fe-N doping as a radical precursor in the presence of PMS (1 × 10-5 M) for DEHP removal. The innovative SFBC/PMS, N-SFBC/PMS, and Fe-N-SFBC/PMS systems could remove 82%, 65%, and 90% of the DEHP at pH 3 in 60 min, respectively. The functionalized Fe3O4 and heteroatom (N) co-doped SFBC composite catalysts within a hydroxyapatite-based structure demonstrated the efficient action of PMS compared to pristine SFBC, which was attributed to its synergistic behavior, generating reactive radicals (SO4•-, HO•, and O2•-) and non-radicals (1O2) involved in DEHP decontamination. DEHP was significantly removed using the combined Fe-N-SFBC/PMS system, revealing that indigenous benthic microorganisms enhance their performance in DEHP-containing sediments. Further, DEHP-induced perturbation was particularly related to the Proteobacteria phylum, whereas Sulfurovum genus and Sulfurovum lithotrophicum species were observed. This study presents a sustainable method for practical, green marine sediment remediation via PMS-CAOP-induced processes using a novel Fe-N-SFBC composite material and biodegradation synergy.


Assuntos
Carvão Vegetal , Dietilexilftalato , Ácidos Ftálicos , Plastificantes , Peróxidos , Carbono , Sedimentos Geológicos
19.
Environ Pollut ; 348: 123865, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38548162

RESUMO

Singlet oxygen (1O2) is a reactive species for the selective degradation of stubborn organic pollutants. Given its resistance to harsh water environment, the effective and exclusive generation of 1O2 is acknowledged as a key strategy to mitigate water production costs and ensure water supply safety. Herein, we synthesized MnOx intercalated MnFe layered double hydroxides (MF-MnOx) to selectively produce 1O2 through the activation of PMS. The distinctive confined structure endowed MF-MnOx with a special pathway for the PMS activation. The direct oxidation of BPA on the intercalated MnOx induced the charge imbalance in the MnFe-LDH layer, resulting in the selective generation of 1O2. Moreover, acceptable activity deterioration of MF-MnOx was observed in a 10 h continuous degradation test in actual water, substantiating the application potential of MF-MnOx. This work presents a novel catalyst for the selective production of 1O2, and evaluates its prospects in the remediation of micro-polluted water.


Assuntos
Peróxidos , Oxigênio Singlete , Oxigênio Singlete/química , Peróxidos/química , Hidróxidos/química , Água , Oxigênio
20.
Environ Pollut ; 348: 123891, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552768

RESUMO

Underwater bubbling plasma (UBP) coupled with diatomite-CoFe2O4 (Dt-CFO) activated peroxymonosulfate (PMS) was proposed for the degradation of ciprofloxacin hydrochloride (CIP) in this work. The catalyst sample of Dt-CFO with large specific surface area, rich active sites and excellent magnetic property was prepared by the hydrothermal method and systematically characterized to investigate its material properties. The combination of UBP and Dt-CFO activated PMS (UBP/Dt-CFO/PMS) showed excellent synergy with the synergistic factor of 1.98, and reached the CIP degradation percentage of 94.7%, which corresponded to the kinetic constant of 0.097 min-1. Dt-CFO with the diatomite content of 30 wt% achieved the best catalytic activity in the reaction system. Higher catalyst and PMS dose, peak voltage, pulse frequency and lower initial CIP concentration were beneficial for CIP removal. The addition of Cl-, HCO3-, SO42- and humic acid suppressed CIP degradation, while NO3- had no effect on CIP removal. The Dt-CFO composite exhibited excellent reusability and low leaching metal amount, demonstrating its good stability. SO4-·, ·OH, ·O2-, 1O2, eaq, O3 and H2O2 were the active species confirmed to be involved in CIP degradation. The redox circles of ≡ Co(Ⅱ)/≡Co(Ⅲ) and ≡ Fe(Ⅱ)/≡Fe(Ⅲ) on Dt-CFO surface and the plasma-induced physicochemical effects dominated PMS activation. The decomposition process of CIP was explored through fluorescence spectra. Three degradation pathways were inferred, and the toxicity analysis showed the toxicity of CIP solution weakened after discharge treatment.


Assuntos
Ciprofloxacina , Terra de Diatomáceas , Peróxido de Hidrogênio , Ciprofloxacina/análise , Compostos Férricos , Peróxidos/química , Oxirredução
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