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1.
Environ Sci Technol ; 58(15): 6704-6715, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38574268

RESUMO

The transformation of toxic arsine (AsH3) gas into valuable elemental arsenic (As0) from industrial exhaust gases is important for achieving sustainable development goals. Although advanced arsenic removal catalysts can improve the removal efficiency of AsH3, toxic arsenic oxides generated during this process have not received adequate attention. In light of this, a novel approach for obtaining stable As0 products was proposed by performing controlled moderate oxidation. We designed a tailored Ni-based catalyst through an acid etching approach to alter interactions between Ni and NaY. As a result, the 1Ni/NaY-H catalyst yielded an unprecedented proportion of As0 as the major product (65%), which is superior to those of other reported catalysts that only produced arsenic oxides. Density functional theory calculations clarified that Ni species changed the electronic structure of oxygen atoms, and the formed [NiIII-OH (µ-O)] active centers facilitated the adsorption of AsH2*, AsH*, and As* reaction intermediates for As-H bond cleavage, thereby decreasing the direct reactivity of oxygen with the arsenic intermediates. This work presents pioneering insights into inhibiting excessive oxidation during AsH3 removal, demonstrating potential environmental applications for recovery of As0 from toxic AsH3.


Assuntos
Arsênio , Zeolitas , Níquel/química , Elétrons , Oxigênio , Gases
2.
Environ Sci Pollut Res Int ; 31(16): 24398-24411, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38441737

RESUMO

CH3SH is a potential hazard to both chemical production and human health, so controlling its emissions is an urgent priority. In this work, a series of transition metal-loaded H-ZSM-5 adsorbents (Si/Al = 25) (Cu, Fe, Co, Ni, Mn, and Zn) were synthesized through the wet impregnation method and tested for CH3SH physicochemical adsorption at 60 °C. It was shown that the Cu-modified H-ZSM-5 adsorbent was much more active for CH3SH removal due to its abundant strong acid sites than other transition metal-modified H-ZSM-5 adsorbents. The detailed physicochemical properties of various modified H-ZSM-5 adsorbents were characterized by SEM, XRD, N2 physisorption, XPS, H2-TPR, and NH3-TPD. The effects of metal loading mass ratio, calcination temperature, and acid or alkali modification on the performance of the adsorbent were also investigated, and finally 20% Cu/ZSM-5 was found to have the best adsorption capacity after calcined at 350 °C. Additionally, the Cu/ZSM-5 adsorbent modified by sodium bicarbonate could expose more active components, which improved the adsorbent's stability. However, the consumption and reduction of the active component Cu2+ and the accumulation of sulfate during the adsorption process are the main reasons for the deactivation of the adsorbent. In addition, the simultaneous purging of N2 + O2 can effectively restore the adsorption capacity of the deactivated adsorbent and can be used as a potential strategy to regenerate the adsorbent.


Assuntos
Elementos de Transição , Humanos , Adsorção , Cobre/química , Temperatura
3.
Environ Sci Technol ; 58(10): 4802-4811, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38427711

RESUMO

Economic and environmentally friendly strategies are needed to promote the bifunctional catalytic removal of carbonyl sulfide (COS) by hydrolysis and hydrogen sulfide (H2S) by oxidation. N doping is considered to be an effective strategy, but the essential and intrinsic role of N dopants in catalysts is still not well understood. Herein, the conjugation of urea and biochar during Cu/biochar annealing produced pyridine N, which increased the combined COS/H2S capacity of the catalyst from 260.7 to 374.8 mg·g-1 and enhanced the turnover frequency of H2S from 2.50 × 10-4 to 5.35 × 10-4 s-1. The nucleophilic nature of pyridine N enhances the moderate basic sites of the catalyst, enabling the attack of protons and strong H2O dissociation. Moreover, pyridine N also forms cavity sites that anchor CuO, improving Cu dispersion and generating more reactive oxygen species. By providing original insight into the pyridine N-induced bifunctional catalytic removal of COS/H2S in a slightly oxygenated and humid atmosphere, this study offers valuable guidance for further C═S and C-S bond-breaking in the degradation of sulfur-containing pollutants.


Assuntos
Sulfeto de Hidrogênio , Óxidos de Enxofre , Sulfeto de Hidrogênio/metabolismo , Carvão Vegetal , Piridinas
4.
Environ Pollut ; 346: 123544, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38367689

RESUMO

A plethora of studies have shown the prominent hepatotoxicity caused by perfluorooctane sulfonate (PFOS), yet the research on the causality of F-53 B (an alternative for PFOS) exposure and liver toxicity, especially in mammals, is largely limited. To investigate the effects that chronic exposure to F-53 B exert on livers, in the present study, male SD rats were administrated with F-53 B in a certain dose range (0, 1, 10, 100, 1000 µg/L, eight rats per group) for 6 months via drinking water and the hepatotoxicity resulted in was explored. We reported that chronic exposure to 100 and 1000 µg/L F-53 B induced remarkable histopathological changes in liver tissues such as distinct swollen cells and portal vein congestion. In addition, the increase of cytokines IL-6, IL-2, and IL-8 upon long-term administration of F-53 B demonstrated the high level of inflammation. Moreover, F-53 B exposure was revealed to disrupt the lipid metabolism in the rat livers, mainly manifesting as the upregulation of some proteins involved in lipid synthesis and degradation, including ACC, FASN, SREBP-1c as well as ACOX1. These findings provided new evidence for the adverse effects caused by chronic exposure to F-53 B in rodents. It is crucial for industries, regulatory agencies as well as the public to remain vigilant about the adverse health effects associated with the emerging PFOS substitutes such as F-53 B. Implementation of regular monitoring and risk assessments is of great importance to alleviate environmental concerns towards PFOS alternatives exposure, and furthermore, to minimize the latent health risks to the public health.


Assuntos
Ácidos Alcanossulfônicos , Doença Hepática Induzida por Substâncias e Drogas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Fluorocarbonos , Ratos , Masculino , Animais , Peixe-Zebra/metabolismo , Ratos Sprague-Dawley , Ácidos Alcanossulfônicos/toxicidade , Ácidos Alcanossulfônicos/metabolismo , Fluorocarbonos/toxicidade , Fluorocarbonos/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Mamíferos
5.
Environ Res ; 250: 118498, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38382665

RESUMO

Soil heavy metal pollution is an important issue that affects human health and ecological well-being. In-situ thermal treatment techniques, such as self-sustaining smoldering combustion (SSS), have been widely studied for the treatment of organic pollutants. However, the lack of fuel in heavy metal-contaminated soil has hindered its application. In this study, we used corn straw as fuel to investigate the feasibility of SSS remediation for copper and lead in heavy metal-contaminated soil, as well as to explore the remediation mechanism. The results of the study showed that SSS increased soil pH, electrical conductivity (EC), total phosphorus (TP), total potassium (TK), rapidly available phosphorus (AP), and available potassium (AK), while decreasing total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), and cation exchange capacity (CEC). The oxidation state of copper (Cu) increased from 10% to 21%-40%, and the residual state of lead (Pb) increased from 18% to 51%-73%. The Toxicity characteristic leaching procedure (TCLP) of Cu decreased by a maximum of 81.08%, and the extracted state of Diethylenetriaminepentaacetic acid (DTPA) decreased by 67.63%; the TCLP of Pb decreased by a maximum of 81.87%, and DTPA decreased by a maximum of 85.68%. The study indicates that SSS using corn straw as fuel successfully achieved remediation of heavy metal-contaminated soil. However, SSS does not reduce the content of copper and lead; it only changes their forms in the soil. The main reasons for the fixation of copper and lead during the SSS process are the adsorption of biochar, complexation with -OH functional groups, binding with π electrons, and the formation of crystalline compounds. This research provides a reference for the application of SSS in heavy metal-contaminated soil and has potential practical implications.

6.
Environ Sci Pollut Res Int ; 31(10): 15398-15411, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38294651

RESUMO

The study is about the size distribution and health risks of polycyclic aromatic hydrocarbons (PAHs) in indoor environment of Xuanwei, Southwest China particle samples were collected by Anderson 8-stage impactor which was used to gather particle samples to nine size ranges. Size-segregated samples were collected in indoor from a rural village in Xuanwei during the non-heating and heating seasons. The results showed that the total concentrations of the indoor particulate matter (PM) were 757 ± 60 and 990 ± 78 µg/m3 in non-heating and heating seasons, respectively. The total concentration of indoor PAHs reached to 8.42 ± 0.53 µg/m3 in the heating season, which was considerably greater than the concentration in the non-heating season (2.85 ± 1.72 µg/m3). The size distribution of PAHs showed that PAHs were mainly enriched in PMs with the diameter <1.1 µm. The diagnostic ratios (DR) and principal component analysis (PCA) showed that coal and wood for residential heating and cooking were the main sources of indoor PAHs. The results of the health risk showed that the total deposition concentration (DC) in the alveolar region (AR) was 0.25 and 0.68 µg/m3 in the non-heating and heating seasons respectively. Throughout the entire sampling periods, the lifetime cancer risk (R) based on DC of children and adults varied between 3.53 ×10-5 to 1.79 ×10-4. During the heating season, the potential cancer risk of PAHs in adults was significant, exceeding 10-4, with a rate of 96%.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Neoplasias , Hidrocarbonetos Policíclicos Aromáticos , Criança , Humanos , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluição do Ar em Ambientes Fechados/análise , Material Particulado/análise , Poeira/análise , China , Carvão Mineral/análise
7.
Angew Chem Int Ed Engl ; 63(11): e202318492, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38265308

RESUMO

Monoatomic dispersion of precious metals on the surface of CeO2 nanocrystals is a highly practical approach for dramatically reducing the usage of precious metals while exploiting the unique properties of single-atom catalysts. However, the specific atomic sites for anchoring precious metal atoms on the CeO2 support and underlying chemical mechanism remain partially unknown. Herein, we show that the terminal hydroxyls on the (100) surface are the most stable sites for anchoring Ag atoms on CeO2 , indicating that CeO2 nanocubes are the most efficient substrates to achieve monoatomic dispersion of Ag. Importantly, the newly identified chemical mechanism for single-metal-atom dispersion on CeO2 nanocubes appears to be generic and can thus be extended to other precious metals (Pt and Pd). In fact, our experiments also show that atomically dispersed Pt/Pd species exhibit morphology- and temperature-dependent CO selectivity in the catalytic CO2 hydrogenation reaction.

8.
J Mol Model ; 30(1): 21, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38170322

RESUMO

CONTEXT: The hydrogen cyanide (HCN) hydrolysis reaction mechanism over Al-doped graphene was investigated through the density functional theory method. HCN preferentially adsorbed vertically on the Al top site to form a stable adsorption configuration. H2O preferentially adsorbed parallel on the Al top site to form a stable adsorption configuration. The competitive adsorption of HCN and H2O weakened the adsorption stability of each molecule over Al-doped graphene. The break of C-N and H-O bonds was the key process in the preferential fracture pathway of the C-H bond. The break of C-N and C-H bonds was the key process in the preferential fracture pathway of the H-O bond. HCN played the role of bridge in the joint adsorption process. H atom transfer and C-N bond cleavage promoted the generation of CO and NH3. The change in the order of H atom transfer determined the reaction energy barrier. NH2CHO was more likely to act as an intermediate to promote the hydrolysis process. METHODS: The calculation work was achieved from the Dmol3 program in Material Studio 2017 using the GGA/PBE method with DNP basis, including the geometric structure and reaction pathway optimization, and adsorption energy calculation. All calculations were performed using a spin-polarized set and the TS method was used for DFT-D correction.

9.
J Phys Chem Lett ; 15(5): 1397-1411, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38290208

RESUMO

To understand the mechanisms of enhanced catalytic technologies under nonthermal plasma (NTP) conditions, complex surface processes must be assessed. However, the predictive capability of the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) processes is limited by various factors. The present study aimed to clarify the interaction mechanisms between NTP and catalysts in the enhancement process, explore the specific pathways of the enhancement process based on E-R and L-H model validations, and obtain data to support the rational design of NTP-enhanced catalytic processes. We investigated CuCeOx catalysts and SO2 removal reaction as a probing reaction using two enhancement scheme configurations, combined with gas-phase reaction process simulations. During the gas-phase reaction stage of the enhancement process, no significant differences were observed among the different configurations caused by the generation of radicals that were induced by N2 (A3Σu+)-excited species. However, introducing CuCeOx catalysts altered the enhancement process, and the placement of the catalyst influenced the corresponding desulfurization mechanism.

10.
J Hazard Mater ; 465: 133431, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38185091

RESUMO

Phosphogypsum (PG) is a major industrial by-product of wet process phosphoric acid production, and untreated PG stockpiled on land will cause severe environmental pollution. Thermal treatment of PG is currently the mainstream treatment method PG can be thermally decomposed to produce CaO, and the decomposition process produces large amounts of SO2. In this paper, phosphate slurry was used to absorb SO2 generated during the PG decomposition to produce phosphoric acid. The effects of operating conditions such as pressure, inlet SO2 concentration, and additive content on the desulfurization efficiency, as well as phosphoric acid yield, were investigated. Under the optimal experimental parameters, the desulfurization efficiency was 100% in the first 3 h, and decreased to 67.42% after 5 h, the maximum phosphate concentration in the solution was 1445.92 mg/L. The Density functional theory (DFT) calculations showed that SO2 and O2 adsorbed on the surface of P2O5 underwent to generate SO3, which can react with H2O to produce H2SO4. Moreover, it was found that Fe3+ could enhance the catalytic oxidation process of SO2 and O2 by decreasing the reaction energy barrier. This study should be helpful for the recycling of phosphorus resources.

11.
Biosci Rep ; 44(1)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38059429

RESUMO

Enzymes in uracil-DNA glycosylase (UDG) superfamily are involved in removal of deaminated nucleobases such as uracil, methylcytosine derivatives such as formylcytosine and carboxylcytosine, and other base damage in DNA repair. UDGX is the latest addition of a new class to the UDG superfamily with a sporadic distribution in bacteria. UDGX type enzymes have a distinct biochemical property of cross-linking itself to the resulting AP site after uracil removal. Built on previous biochemical and structural analyses, this work comprehensively investigated the kinetic and enzymatic properties of Mycobacterium smegmatis UDGX. Kinetics and mutational analyses, coupled with structural information, defined the roles of E52, D56, D59, F65 of motif 1, H178 of motif 2 and N91, K94, R107 and H109 of motif 3 play in uracil excision and cross-linking. More importantly, a series of quantitative analyses underscored the structural coupling through inter-motif and intra-motif interactions and subsequent functional coupling of the uracil excision and cross-linking reactions. A catalytic model is proposed, which underlies this catalytic feature unique to UDGX type enzymes. This study offers new insight on the catalytic mechanism of UDGX and provides a unique example of enzyme evolution.


Assuntos
Reparo do DNA , Uracila-DNA Glicosidase , Uracila-DNA Glicosidase/química , Uracila-DNA Glicosidase/genética , Uracila-DNA Glicosidase/metabolismo , Catálise , Uracila
12.
Environ Sci Technol ; 58(1): 859-870, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38060830

RESUMO

The efficient removal of the highly toxic arsine gas (AsH3) from industrial tail gases under mild conditions remains a formidable challenge. In this study, we utilized the confinement effect of defective carbon nanotubes to fabricate a CuO cluster catalyst (CuO/ACNT), which exhibited a capacity much higher than that of CuO supported on pristine multiwalled carbon nanotubes (MWCNT) (CuO/PCNT) for catalytically oxidizing AsH3 under ambient conditions. The experimental and theoretical results show that nitric acid steam treatment could induce MWCNT surface structural defects, which facilitated more stable anchoring of CuO and then improved the oxygen activation ability, therefore leading to excellent catalytic performance. Density functional theory (DFT) calculations revealed that the catalytic oxidation of AsH3 proceeded through stepwise dehydrogenation and subsequent recombination with oxygen to form As2O3 as the final product.


Assuntos
Nanotubos de Carbono , Nanotubos de Carbono/química , Temperatura , Gases , Oxigênio , Oxirredução
13.
J Hazard Mater ; 465: 133075, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38016318

RESUMO

The environmental problem caused by industrial emissions of NOx has been studied in the past dacades. In this study, red mud coupling with phosphorus sludge were used to enhance the solution to absorb NOx from the flue gas. Firstly, red mud reacted with the binder silicic acid in the phosphorus sludge, destroying the emulsion structure of the phosphorus sludge. Then, the P4 in the phosphorus sludge is completely released, and the P4 reacted with O2 in the flue gas to produce O3 and O. NO and NO2 contained in the flue gas reacted with the active O and O3 to produce high-valent NOx, such as NO3, N2O5. At last, the mixed slurry of red mud and phosphorus sludge absorbed the high-valent NOx, resulting in the formation of Ca5(PO4)3F along with HNO3. Using phosphorus sludge to produce O3 in the reaction process can reduce the production cost of O3 and achieve waste utilization. Meanwhile, the interaction between red mud and phosphorus sludge can promote phosphorus sludge to produce O3 and remove F- from phosphorus sludge, as well as avoid the problem of secondary pollution. This study should be helpful for red mud and phosphorus sludge utilization and flue gas denitration.

14.
Small ; 20(8): e2304110, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37806756

RESUMO

Atherosclerosis (AS) is the primary reason behind cardiovascular diseases, leading to approximately one-third of global deaths. Developing a novel multi-model probe to detect AS is urgently required. Macrophages are the primary cells from which AS genesis occurs. Utilizing natural macrophage membranes coated on the surface of nanoparticles is an efficient delivery method to target plaque sites. Herein, Fe3 O4 -Cy7 nanoparticles (Fe3 O4 -Cy7 NPs), functionalized using an M2 macrophage membrane and a liposome extruder for Near-infrared fluorescence and Magnetic resonance imaging, are synthesized. These macrophage membrane-coated nanoparticles (Fe3 O4 @M2 NPs) enhance the recognition and uptake using active macrophages. Moreover, they inhibit uptake using inactive macrophages and human coronary artery endothelial cells. The macrophage membrane-coated nanoparticles (Fe3 O4 @M0 NPs, Fe3 O4 @M1 NPs, Fe3 O4 @M2 NPs) can target specific sites depending on the macrophage membrane type and are related to C-C chemofactor receptor type 2 protein content. Moreover, Fe3 O4 @M2 NPs demonstrate excellent biosafety in vivo after injection, showing a significantly higher Fe concentration in the blood than Fe3 O4 -Cy7 NPs. Therefore, Fe3 O4 @M2 NPs effectively retain the physicochemical properties of nanoparticles and depict reduced immunological response in blood circulation. These NPs mainly reveal enhanced targeting imaging capability for atherosclerotic plaque lesions.


Assuntos
Aterosclerose , Nanopartículas , Humanos , Células Endoteliais , Nanopartículas/química , Imageamento por Ressonância Magnética/métodos , Aterosclerose/diagnóstico por imagem
15.
J Environ Sci (China) ; 139: 182-192, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105046

RESUMO

Waste calcium carbide slags (CS), which are widely applied to desulfurisation, are not typically used in denitration. Herein, to well achieve waste control by waste, a facile and high-efficiency denitration strategy is developed using KOH to modify the calcium carbide slags (KCS). Various KCS samples were investigated using a series of physical and chemical characterisations. The performance test results showed that the KOH concentration and reaction temperature are the main factors affecting the denitration efficiency of KCS, and CS modified with 1.5 mol/L KOH (KCS-1.5) can achieve 100% denitration efficiency at 300°C. Such excellent removal efficiency is due to the catalytic oxidation of the oxygen-containing functional groups derived from the KCS. Further studies showed that KOH treatment significantly increased the concentration of oxygen vacancies, nitro compounds, and basic sites of CS. This study provides a novel strategy for the resource utilisation of waste CS in the future.


Assuntos
Acetileno , Oxigênio , Temperatura , Oxirredução , Oxigênio/química
16.
Emerg Med Int ; 2023: 9697442, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38077106

RESUMO

Background: High-quality cardiopulmonary resuscitation (CPR) is a key element in the rescue of cardiac arrest patients but is difficult to achieve in circumstances involving aerosol transmission, such as the COVID-19 pandemic. Methods: This prospective randomized crossover trial included 30 experienced health care providers to evaluate the impact of personal protective equipment (PPE) on CPR quality and rescuer safety. Participants were asked to perform continuous CPR for 5 minutes on a manikin with three types of PPE: level D-PPE, level C-PPE, and PAPR. The primary outcome was effective chest compression per minute. Secondary outcomes were the fit factor by PortaCount, vital signs and fatigue scores before and after CPR, and perceptions related to wearing PPE. Repeated-measures ANOVA was used, and a two-tailed test value of 0.05 was considered statistically significant. Results: The rates of effective chest compressions for 5 minutes with level D-PPE, level C-PPE, and PAPRs were 82.0 ± 0.2%, 78.4 ± 0.2%, and 78.0 ± 0.2%, respectively (p = 0.584). The fit-factor test values of level C-PPE and PAPRs were 182.9 ± 39.9 vs. 198.9 ± 9.2 (p < 0.001). The differences in vital signs before and after CPR were not significantly different among the groups. In addition, the fatigue and total perception scores of wearing PPE were significantly higher for level C-PPE than PAPRs: 3.8 ± 1.6 vs. 3.0 ± 1.6 (p < 0.001) and 27.9 ± 5.4 vs. 26.0 ± 5.3 (p < 0.001), respectively. Conclusion: PAPRs are recommended when performing CPR in situations where aerosol transmission is suspected. When PAPRs are in short supply, individual fit-tested N95 masks are an alternative. This trial is registered with NCT04802109.

17.
Environ Sci Technol ; 57(45): 17553-17565, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37917662

RESUMO

The hydrogenation of organic sulfur (CS2) present in industrial off-gases to produce sulfur-free hydrocarbons and H2S can be achieved by using noble-metal catalysts. However, there has been a lack of comprehensive investigation into the underlying reaction mechanisms associated with this process. In this study, we have conducted an in-depth examination of the activity and selectivity of Pt- and Pd-loaded alumina-based catalysts, revealing significant disparities between them. Notably, Pd/Al2O3 catalysts exhibit an enhanced performance at low temperatures. Furthermore, we have observed that CS2 displays a higher propensity for conversion to methane when employing Pt/Al2O3 catalysts, while Pd/Al2O3 catalysts demonstrate a greater tendency for coke deposition. By combining experimental observations with theoretical calculations, we revealed that the capability of H2 spillover along with the adsorption capacity of CS2, play pivotal roles in determining the observed differences. Moreover, the key intermediate species involved in the methanation and coke pathways were identified. The intermediate CH2S* is found to be crucial in the methanation pathway, while the intermediate CSH* is identified as significant in the coke pathway.


Assuntos
Coque , Adsorção , Óxido de Alumínio , Hidrogenação , Enxofre
18.
J Hazard Mater ; 460: 132323, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37666174

RESUMO

Passivation of nanoscale zero valent iron (nZVI, Fe0) impaired its longevity while black TiO2 (b-TiO2) suffered from restricted optical properties. Using a facile approach, a novel Z-scheme heterojunction catalyst (Fe0@CQDs-TiO2(b)) of nZVI decorated with carbon quantum dots (CQDs) implanted into b-TiO2 was designed. Characterization results revealed the optical potential of the passivation coating of nZVI. The incorporation of CQDs stimulated the creation of active •OH during the dark reaction, and led to an accelerated mobility of photo-excited carriers of b-TiO2 and optimized its band gap (narrowing from 2.36 eV to 2.15 eV) during the light reaction. The photo-elimination capacity of metronidazole (MNZ) on Fe0@CQDs-TiO2(b) (99.36%) was 2.64, 8.25 and 1.34 fold beyond that on nZVI, b-TiO2 and Fe0@b-TiO2, respectively. The assembled material offered excellent adaptability to environmental substrates, in addition to being virtually unaffected by tap (95.62%) and river water (92.62%). The mechanism of MNZ degradation was elaborated, and the combination of density functional theory (DFT) calculations and LC-MS discerned 12 intermediates and 3 routes. Toxicity assessment of these products was conducted to ensure no inadvertent negative environmental impacts arose. This work proposed an original direction and mechanism for the application of passivation layers in nZVI-based materials for environmental restoration.

19.
Langmuir ; 39(37): 13090-13102, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37669076

RESUMO

Gaseous thallium (Tl) pollution events, primarily caused by non-ferrous mineral refineries and fossil fuel combustion, have increased over the past few decades. To prevent gaseous Tl distribution from flue gas, MnO2/CeO2@HKUST-1 (MCH) was synthesized and found to achieve a gaseous Tl(I) removal level of up to 90% at 423 K, a weight hourly space velocity (WHSV) of 2000 h-1/mL with an Mn dose of 10%, maintained over 10 h. The best Mn/Ce ratio was found to be 9:1. To further investigate surface kinetic behavior, four commonly used kinetic models were applied, including the Eley-Rideal (ER) model, Langmuir-Hinshelwood (LH) model, Mars-van Krevelen (MVK) model, and pseudo-first-order (PFO) model. While the ER and LH models had the slightest deviation, the MVK model was the most reliable. The CatMAP software was also used to match the simulation deviation. This work demonstrated the Tl removal mechanism and provided insights into the accuracy of kinetic models on minor-radius heavy metal. Thus, this research may help promote the design of reactors, heavy metal removal rates, and flue gas purification technology selection.

20.
Sci Total Environ ; 903: 166285, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37586511

RESUMO

Copper oxide nanoparticles (CuO NPs) can adversely affect lung health possibly by inducing oxidative damage through the release of copper ions. However, the migration and transformation processes of CuO NPs in lung lining fluid is still unclear, and there are still conflicting reports of redox reactions involving copper ions. To address this, we examined the release of copper ions from CuO NPs in simulated lung fluid supplemented with pulmonary surfactant (PS), and further analyzed the mechanisms of PS-CuO NPs interactions and the health hazards. The results showed that the phospholipid of PS was adsorbed on the particle surface, which not only induced aggregation of the particles but also provided a reaction environment for the interaction of PS with CuO NPs. PS was able to promote the release of ions from CuO NPs, of which the protein was a key component. Lipid peroxidation, protein destabilization, and disruption of the interfacial chemistry also occurred in the PS-CuO NPs interactions, during which copper ions were present only as divalent cations. Meanwhile, the contribution of the particle surface cannot be neglected in the oxidative damage to the lung caused by CuO NPs. Through reacting with biomolecules, CuO NPs accomplished ion release and induced oxidative damage associated with PS. This research was the first to reveal the mechanism of CuO NPs releasing copper ions and inducing lipid oxidative damage in the presence of PS, which provides a new idea of transition metal-induced health risk in human body.

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