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1.
Environ Geochem Health ; 46(7): 221, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849635

RESUMO

This study reported the synthesis and assessment of zinc oxide/iron oxide (ZnO/Fe2O3) nanocomposite as photocatalysts for the degradation of a mixture of methylene red and methylene blue dyes. X-ray diffraction analysis confirms that the crystallite of zinc oxide (ZnO) has a hexagonal wurtzite phase and iron oxide (Fe2O3) has a rhombohedral phase. Fourier Transform Infra-Red spectrum confirms the presence of Zn-O vibration stretching at 428, 480 and 543 cm-1 stretching confirming Fe-O bond formation. Scanning Electron Microscope images exhibited a diverse size and shape of the nanocomposites. The ZnO-90%/Fe2O3-10% and ZnO-10%/Fe2O3-90% nanocomposites reveal good photocatalytic activity with reaction rate constants of 1.5 × 10-2 and 0.66 × 10-2; and 1.3 × 10-2 and 0.60 × 10-2 for methylene blue and methyl red dye respectively. The results revealed that the synthesized ZnO/Fe2O3 nanocomposite is the best catalyst for dye degradation and can be used for industrial applications in future.


Assuntos
Corantes , Compostos Férricos , Azul de Metileno , Nanocompostos , Óxido de Zinco , Óxido de Zinco/química , Nanocompostos/química , Azul de Metileno/química , Compostos Férricos/química , Catálise , Corantes/química , Difração de Raios X , Microscopia Eletrônica de Varredura , Compostos Azo/química , Poluentes Químicos da Água/química , Fotólise , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Artigo em Inglês | MEDLINE | ID: mdl-38856773

RESUMO

The biosynthesis of novel nanoparticles with varied morphologies, which has good implications for their biological capabilities, has attracted increasing attention in the field of nanotechnology. Bioactive compounds present in the extract of fungi, bacteria, plants and algae are responsible for nanoparticle synthesis. In comparison to other biological resources, brown seaweeds can also be useful to convert metal ions to metal nanoparticles because of the presence of richer bioactive chemicals. Carbohydrates, proteins, polysaccharides, vitamins, enzymes, pigments, and secondary metabolites in brown seaweeds act as natural reducing, capping, and stabilizing agents in the nanoparticle's synthesis. There are around 2000 species of seaweed that dominate marine resources, but only a few have been reported for nanoparticle synthesis. The presence of bioactive chemicals in the biosynthesized metal nanoparticles confers biological activity. The biosynthesized metal and non-metal nanoparticles from brown seaweeds possess different biological activities because of their different physiochemical properties. Compared with terrestrial resources, marine resources are not much explored for nanoparticle synthesis. To confirm their morphology, characterization methods are used, such as absorption spectrophotometer, X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. This review attempts to include the vital role of brown seaweed in the synthesis of metal and non-metal nanoparticles, as well as the method of synthesis and biological applications such as anticancer, antibacterial, antioxidant, anti-diabetic, and other functions.

3.
Environ Res ; 256: 119217, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38788788

RESUMO

Nowadays, for soil stabilisation and cleaner production of geo-composites, the possibility of utilizing waste rubber is in vogue. The present paper deals with experimentally investigating the mechanical and micro-structural characteristics of weak Indian clayey soil partially substituted with lime (0-3.5%) and waste rubber tyre powder (0-15%). It was observed that, with increasing lime and rubber powder content, the plasticity index of the soil decreases. The shear strength and compaction testing results reveal that adding lime and rubber tyre powder (RTP) enhances the geotechnical performance of clayey soil up to an optimum dosage value. Also, the tri-axial shear testing was performed to obtain stress-strain curves for all considered soil mixes. For modified clayey soil containing 3% lime and 12.5% rubber powder, the cohesion values and bearing capacities improved phenomenally by 36.1% and 88.6% respectively, when compared to clayey soil. Further for this mix, SEM analysis reveals a compacted microstructure which improves dry-density and California's bearing ratio among all modified mixes. The novel co-relations upon regression analysis are found able to predict plasticity index, dry density, bearing capacity and shear strength with higher confidence levels. Overall, the cost-benefit analysis worked out to obtain the optimum cost of construction of footings and flexible pavement shows cost deductions up to 19% and 39% respectively while utilizing modified clay soil mixes containing 3% lime and 12.5% rubber powder in subgrade, ultimately making production stronger, cheaper and environment friendly.


Assuntos
Compostos de Cálcio , Argila , Óxidos , Borracha , Solo , Compostos de Cálcio/química , Óxidos/química , Borracha/química , Solo/química , Argila/química , Silicatos de Alumínio/química
4.
Mol Biotechnol ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658470

RESUMO

Cordyceps, an entomopathogenic fungus belonging to the Ascomycota phylum, is a familiar remedial mushroom that is extensively used in the traditional medicinal system, especially in South Asian nations. The significance of this genus' members in a range of therapeutic and biotechnological applications has long been acknowledged. The exceedingly valuable fungus Ophiocordyceps sinensis (Cordyceps sinensis) is found in the alpine meadows of Bhutan, Nepal, Tibet, and India, where it is severely harvested. Driven by market demand and ecological concerns, the study highlights challenges in natural C. sinensis collection and emphasizes the shift towards sustainable artificial cultivation methods. This in-depth review navigates Cordyceps cultivation strategies, focusing on C. sinensis and the viable alternative, C. militaris. The escalating demand for Cordyceps fruiting bodies and bioactive compounds prompts a shift toward sustainable artificial cultivation. While solid-state fermentation on brown rice remains a traditional method, liquid culture, especially submerged and surface/static techniques, emerges as a key industrial approach, offering shorter cultivation periods and enhanced cordycepin production. The review accentuates the adaptability and scalability of liquid culture, providing valuable insights for large-scale Cordyceps production. The future prospects of Cordyceps cultivation require a holistic approach, combining scientific understanding, technological innovation, and sustainable practices to meet the demand for bioactive metabolites while ensuring the conservation of natural Cordyceps populations.

5.
Environ Res ; 251(Pt 2): 118617, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38467362

RESUMO

This study aims to improve the quality of fuel with high calorific value namely Sfuel - a commercial high-quality refuse-derived fuel (RDF) from hazardous waste via modifying the process design and operating parameters of thermal conversion process. The study analyses key parameters of RDF quality, such as calorific value and heavy metal content, before and after process modifications based on the combination of experimental and simulation using Aspen Plus. In this study, the temperature and pressure of the simulation system are varied from 100 to 700 °C and from 1 to 5 bar, respectively. Findings indicate that there are a total of eleven heavy metals and 179 volatile compounds in the "Sfuels". The quality of the targeted product is greatly improved by the metal evaporation at high temperatures and pressures. However, the calorific value of RDF significantly decreases at 700 °C due to a large amount of the carbon content being evaporated. Although the carbon content at high temperatures is significantly lost, the heat from the vapour stream reactor outlet, which is reused to preheat the nitrogen gas stream supplied to the system, reduces energy consumption while improving the thermal conversion efficiency of the system. Besides, low pressure along with high temperature are not the optimal conditions for quality Sfuels improvement by thermal conversion. Results also indicate that electric heating is more economically efficient than natural gas heating.


Assuntos
Metais Pesados , Metais Pesados/análise , Eliminação de Resíduos/métodos , Simulação por Computador , Resíduos Perigosos/análise , Temperatura Alta
6.
Sci Rep ; 14(1): 5855, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467729

RESUMO

The antifungal efficacy and cytotoxicity of a novel nano-antifungal agent, the Fe3O4@SiO2/Schiff-base complex of Cu(II) magnetic nanoparticles (MNPs), have been assessed for targeting drug-resistant Candida species. Due to the rising issue of fungal infections, especially candidiasis, and resistance to traditional antifungals, there is an urgent need for new therapeutic strategies. Utilizing Schiff-base ligands known for their broad-spectrum antimicrobial activity, the Fe3O4@SiO2/Schiff-base/Cu(II) MNPs have been synthesized. The Fe3O4@SiO2/Schiff-base/Cu(II) MNPs was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Energy-dispersive X-ray (EDX), Vibrating Sample Magnetometer (VSM), and Thermogravimetric analysis (TGA), demonstrating successful synthesis. The antifungal potential was evaluated against six Candida species (C. dubliniensis, C. krusei, C. tropicalis, C. parapsilosis, C. glabrata, and C. albicans) using the broth microdilution method. The results indicated strong antifungal activity in the range of 8-64 µg/mL with the lowest MIC (8 µg/mL) observed against C. parapsilosis. The result showed the MIC of 32 µg/mL against C. albicans as the most common infection source. The antifungal mechanism is likely due to the disruption of the fungal cell wall and membrane, along with increased reactive oxygen species (ROS) generation leading to cell death. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay for cytotoxicity on mouse L929 fibroblastic cells suggested low toxicity and even enhanced cell proliferation at certain concentrations. This study demonstrates the promise of Fe3O4@SiO2/Schiff-base/Cu(II) MNPs as a potent antifungal agent with potential applications in the treatment of life-threatening fungal infections, healthcare-associated infections, and beyond.


Assuntos
Nanopartículas de Magnetita , Micoses , Animais , Camundongos , Antifúngicos/farmacologia , Antifúngicos/química , Dióxido de Silício/farmacologia , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas de Magnetita/química , Candida , Candida albicans , Candida parapsilosis , Testes de Sensibilidade Microbiana
7.
Environ Res ; 250: 118528, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38403150

RESUMO

Agriculture is a leading sector in international initiatives to mitigate climate change and promote sustainability. This article exhaustively examines the removals and emissions of greenhouse gases (GHGs) in the agriculture industry. It also investigates an extensive range of GHG sources, including rice cultivation, enteric fermentation in livestock, and synthetic fertilisers and manure management. This research reveals the complex array of obstacles that are faced in the pursuit of reducing emissions and also investigates novel approaches to tackling them. This encompasses the implementation of monitoring systems powered by artificial intelligence, which have the capacity to fundamentally transform initiatives aimed at reducing emissions. Carbon capture technologies, another area investigated in this study, exhibit potential in further reducing GHGs. Sophisticated technologies, such as precision agriculture and the integration of renewable energy sources, can concurrently mitigate emissions and augment agricultural output. Conservation agriculture and agroforestry, among other sustainable agricultural practices, have the potential to facilitate emission reduction and enhance environmental stewardship. The paper emphasises the significance of financial incentives and policy frameworks that are conducive to the adoption of sustainable technologies and practices. This exhaustive evaluation provides a strategic plan for the agriculture industry to become more environmentally conscious and sustainable. Agriculture can significantly contribute to climate change mitigation and the promotion of a sustainable future by adopting a comprehensive approach that incorporates policy changes, technological advancements, and technological innovations.


Assuntos
Agricultura , Inteligência Artificial , Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Agricultura/métodos , Mudança Climática , Desenvolvimento Sustentável/tendências , Monitoramento Ambiental/métodos , Efeito Estufa , Conservação dos Recursos Naturais/métodos
8.
ACS Omega ; 9(3): 3123-3142, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38284011

RESUMO

As a result of the transformation of inflexible electronic structures into flexible and stretchy devices, wearable electronics now provide great advantages in a variety of fields, including mobile healthcare sensing and monitoring, human-machine interfaces, portable energy storage and harvesting, and more. Because of their enriched surface functionalities, large surface area, and high electrical conductivity, transition metal nitrides and carbides (also known as MXenes) have recently come to be extensively considered as a group of functioning two-dimensional nanomaterials as well as exceptional fundamental elements for forming flexible electronics devices. This Review discusses the most recent advancements that have been made in the field of MXene-enabled flexible electronics for wearable electronics. The emphasis is placed on extensively established nonstructural features in order to highlight some MXene-enabled electrical devices that were constructed on a nanometric scale. These attributes include devices configured in three dimensions: printed materials, bioinspired structures, and textile and planar substrates. In addition, sample applications in electromagnetic interference (EMI) shielding, energy, healthcare, and humanoid control of machinery illustrate the exceptional development of these nanodevices. The increasing potential of MXene nanoparticles as a new area in next-generation wearable electronic technologies is projected in this Review. The design challenges associated with these electronic devices are also discussed, and possible solutions are presented.

9.
Environ Res ; 241: 117627, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37967700

RESUMO

Arsenic is the hazardous species and still is the global challenge in water treatment. Apatite soil is highly rich in arsenic species, and its mining presents various environmental issues. In this study, novel magnetic microbeads as adsorbent were developed for the elimination of hazardous arsenic ions from apatite soil's aqueous leachate before discharging into environment. The microbeads were fabricated with metformin polyether sulfone after being doped with zero-valent iron (Met-PES/ZVI). The microbeads were characterized using various techniques, including FTIR, XRD, SEM-EDX, VSM, and zeta potential analysis. The developed adsorbent demonstrated a significant elimination in arsenic in aqueous leachate, achieving 82.39% removal after 30 min of contact time, which further increased to 90% after 180 min of shaking. The kinetic analysis revealed that the pseudo-second-order model best represented the adsorption process. The intra-particle diffusion model indicated that the adsorption occurred in two steps. The Langmuir model (R2 = 0.991), with a maximum adsorption capacity of 188.679 mg g-1, was discovered to be the best fit for the experimental data as compared Freundlich model (R2 = 0.981). According to the thermodynamic outcome (ΔG < -20 kJ/mol), the adsorption process was spontaneous and involved physisorption. These findings demonstrate the potential of magnetic Met-PES/ZVI microbeads as an efficient adsorbent for the removal of arsenic from apatite soil aqueous leachate.


Assuntos
Arsênio , Poluentes Químicos da Água , Purificação da Água , Arsênio/análise , Solo , Cinética , Microesferas , Termodinâmica , Adsorção , Fenômenos Magnéticos , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Purificação da Água/métodos
10.
Chemosphere ; 346: 140512, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37879373

RESUMO

The augmentation of biogas production can be achieved by incorporating metallic nanoparticles as additives within anaerobic digestion. The objective of this current study is to examine the synthesis of Fe-Ni-Zn and Fe-Co-Zn trimetallic nanoparticles using the co-precipitation technique and assess its impact on anaerobic digestion using palm oil mill effluent (POME) as carbon source. The structural morphology and size of the synthesised trimetallic nanoparticles were analysed using a range of characterization techniques, such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX) . The average size of Fe-Ni-Zn and Fe-Co-Zn were 19-25.5 nm and 19.1-30.5 nm respectively. Further, investigation focused on examining the diverse concentrations of trimetallic nanoparticles, ranging from 0 to 50 mgL-1. The biogas production increased by 55.55% and 60.11% with Fe-Ni-Zn and Fe-Co-Zn trimetallic nanoparticles at 40 mgL-1 and 20 mgL-1, respectively. Moreover, the lowest biogas of 11.11% and 38.11% were found with 10 mgL-1 of Fe-Ni-Zn and Fe-Co-Zn trimetallic nanoparticles. The findings of this study indicated that the trimetallic nanoparticles exhibited interactions with anaerobes, thereby enhancing the degradation process of palm oil mill effluent (POME) and biogas production. The study underscores the potential efficacy of trimetallic nanoparticles as a viable supplement for the promotion of sustainable biogas generation.


Assuntos
Nanopartículas Metálicas , Óleos de Plantas , Óleo de Palmeira , Anaerobiose , Biocombustíveis/análise , Resíduos Industriais/análise
11.
Environ Res ; 246: 118027, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38159670

RESUMO

The study explores co-gasification of palm oil decanter cake and alum sludge, investigating the correlation between input variables and syngas production. Operating variables, including temperature (700-900 °C), air flow rate (10-30 mL/min), and particle size (0.25-2 mm), were optimized to maximize syngas production using air as the gasification agent in a fixed bed horizontal tube furnace reactor. Response Surface Methodology with the Box-Behnken design was used employed for optimization. Fourier Transformed Infra-Red (FTIR) and Field Emission Scanning Electron Microscopic (FESEM) analyses were used to analyze the char residue. The results showed that temperature and particle size have positive effects, while air flow rate has a negative effect on the syngas yield. The optimal CO + H2 composition of 39.48 vol% was achieved at 900 °C, 10 mL/min air flow rate, and 2 mm particle size. FTIR analysis confirmed the absence of C─Cl bonds and the emergence of Si─O bonds in the optimized char residue, distinguishing it from the raw sample. FESEM analysis revealed a rich porous structure in the optimized char residue, with the presence of calcium carbonate (CaCO3) and aluminosilicates. These findings provide valuable insights for sustainable energy production from biomass wastes.


Assuntos
Compostos de Alúmen , Gases , Esgotos , Gases/química , Óleo de Palmeira , Temperatura , Biomassa
12.
Environ Res ; 244: 117952, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38113992

RESUMO

In developing countries like India, an economically viable and ecologically approachable strategy is required to safeguard the drinking water. Excessive fluoride intake through drinking water can lead to dental fluorosis, skeletal fluorosis, or both. The present study has been under with an objective to investigate the feasibility of using cellulose derived from coconut fiber as an adsorbent under varying pH conditions for fluoride elimination from water. The assessment of equilibrium concentration of metal ions using adsorption isotherms is an integral part of the study. This present finding indicates the considerable effect of variation of adsorbent dosages on the fluoride removal efficiency under constant temperature conditions of 25 ± 2 °C with a contact period of 24 h. It is pertinent to mention that maximum adsorption of 88% has been observed with a pH value of 6 with 6 h time duration with fluoride dosage of 50 mg/L. The equilibrium concentration dwindled to 0.4 mg/L at fluoride concentration of 20 mg/L. The Langmuir model designates the adsorption capacity value of 2.15 mg/L with initial fluoride concentration of 0.21 mg/g with R2 value of 0.660. Similarly, the adsorption capacity using Freundlich isotherms is found to be 0.58 L/g and 0.59 L/g with fluoride concentration of 1.84 mg/L and 2.15 mg/L respectively. The results from the present study confirm that coconut fiber possesses appropriate sorption capabilities of fluoride ion but is a pH dependent phenomenon. The outcomes of the study indicate the possible use of cellulose extracted from waste coconut fiber as a low-cost fluoride adsorbent. The present study can be well implemented on real scale systems as it will be beneficial economically as well as environmentally.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Fluoretos , Celulose , Cocos , Tratamento com Flúor , Cinética , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Adsorção
13.
Chemosphere ; 343: 140225, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37742771

RESUMO

Polypropylene composites find widespread application in industries, including packaging, plastic parts, automotive, textiles, and specialized devices like living hinges known for their remarkable flexibility. This study focuses on the manufacturing of polypropylene composite specimens by incorporating varying weight percentages of fly ash particles with polypropylene using a twin-screw extruder and injection molding machine. The composites were comprehensively tested, evaluating tensile, compressive, and flexural strength, solid-state and polymer melt properties, modulus, damping, and thermal response. The findings reveal that the compressive strength of polypropylene increases up to 2 wt% of added fly ash particles and subsequently exhibits a slight decline. Tensile strength demonstrates an increase up to 1 wt% of fly ash, followed by a decrease with a 2 wt% addition, and then a subsequent increase. Flexural strength shows improvement up to 3 wt% fly ash addition before declining. The storage modulus curve is categorized into three regions: the glassy region (up to 0 °C), the glass transition region (0-50 °C), and the glass transition region of polypropylene (>50 °C), each corresponding to different molecular motions. Weight loss curves exhibit similar trends, indicating uniform pyrolysis behavior attributed to consistent chemical bonds. Plastic degradation commences around 440 °C and concludes near 550 °C. Additionally, elemental mapping of fly ash composition identified various elements such as O, Si, K, Mg, Ca, Cl, Na, P, Al, Fe, S, Cu, Ti, and Ni. These findings offer valuable insights into the mechanical and thermal properties of polypropylene composites reinforced with fly ash, rendering them suitable for a wide range of industrial applications necessitating strength and durability across temperature variations.

14.
Environ Res ; 238(Pt 2): 117167, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37722580

RESUMO

In this work, a simple sol-gel approach was used for the preparation of cyanopropyl (CNPr) functionalized silica nanoparticles (SiO2-CNPr) that tetraethoxysilane (TEOS) and cyanopropyltriethoxysilane (CNPrTEOS) used as precursors. This as-prepared SiO2-CNPr nanoparticle sorbent was first characterized using FESEM, EDX, FTIR, TGA, and BET techniques. Then, the SiO2-CNPr nanoparticle was applied as a new SPE sorbent for determining trace levels of OPPs in environmental water samples. To enhance the simultaneous extraction of non-polar or/and polar OPPs and to obtain the most efficient sorbent, several sol-gel synthesis parameters were studied. In addition, the effect of several effective parameters on SPE performance was investigated toward simultaneous extraction of non-polar or/and polar OPPs. Moreover, the figures of merit such as precision, linearity, LOQ, LOD, and recovery were evaluated for the sorbent. Finally, the designed SiO2-CNPr SPE was used to determine OPPs in real water samples, and its extraction performance was compared to commercial cartridges based on cyanopropyl.


Assuntos
Praguicidas , Praguicidas/análise , Dióxido de Silício , Compostos Organofosforados , Extração em Fase Sólida/métodos , Água
15.
Chemosphere ; 339: 139693, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536541

RESUMO

Treating and reusing wastewater has become an essential aspect of water management worldwide. However, the increase in emerging pollutants such as polycyclic aromatic hydrocarbons (PAHs), which are presented in wastewater from various sources like industry, roads, and household waste, makes their removal difficult due to their low concentration, stability, and ability to combine with other organic substances. Therefore, treating a low load of wastewater is an attractive option. The study aimed to address membrane fouling in the submerged membrane bioreactor (SMBR) used for wastewater treatment. An aluminum electrocoagulation (EC) device was combined with SMBR as a pre-treatment to reduce fouling. The EC-SMBR process was compared with a conventional SMBR without EC, fed with real grey water. To prevent impeding biological growth, low voltage gradients were utilized in the EC deviceThe comparison was conducted over 60 days with constant transmembrane pressure and infinite solid retention time (SRT). In phase I, when the EC device was operated at a low voltage gradient (0.64 V/cm), no significant improvement in the pollutants removal was observed in terms of color, turbidity, and chemical oxygen demand (COD). Nevertheless, during phase II, a voltage gradient of 1.26 V/cm achieved up to 100%, 99.7%, 92%, 94.1%, and 96.5% removals in the EC-SMBR process in comparison with 95.1%, 95.4%, 85%, 91.7% and 74.2% removals in the SMBR process for turbidity, color, COD, ammonia nitrogen (NH3-N), total phosphorus (TP), respectively. SMBR showed better anionic surfactant (AS) removal than EC-SMBR. A voltage gradient of 0.64 V/cm in the EC unit significantly reduced fouling by 23.7%, while 1.26 V/cm showed inconsistent results. Accumulation of Al ions negatively affected membrane performance. Low voltage gradients in EC can control SMBR fouling if Al concentration is controlled. Future research should investigate EC-SMBR with constant membrane flux for large-scale applications, considering energy consumption and operating costs.


Assuntos
Poluentes Ambientais , Purificação da Água , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Membranas Artificiais , Eletrocoagulação , Reatores Biológicos , Purificação da Água/métodos , Água/química
16.
Environ Monit Assess ; 195(8): 940, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37436672

RESUMO

Water bodies with the dye methylene blue pose serious environmental and health risks to humans. Therefore, the creation and investigation of affordable, potential adsorbents to remove methylene blue dye from water resources as a long-term fix is one focus of the scientific community. Food plants and other carbon-source serve as a hotspot for a wider range of application on different pollutants that impact the environment and living organisms. Here, we reviewed the use of treated and untreated biosorbents made from plant waste leaves for removing the dye methylene blue from aqueous media. After being modified, activated carbon made from various plant leaves improves adsorption performance. The range of activating chemicals, activation methods, and bio-sorbent material characterisation using FTIR analysis, Barunauer-Emmett-Teller (BET) surface area, scanning electron microscope (SEM-EDX), and SEM-EDX have all been covered in this review. It has been thoroughly described how the pH solution of the methylene blue dye compares to the pHPZC of the adsorbent surface. The presentation also includes a thorough analysis of the application of the isotherm model, kinetic model, and thermodynamic parameters. The selectivity of the adsorbent is the main focus of the adsorption kinetics and isotherm models. It has been studied how adsorption occurs, how surface area and pH affect it, and how biomass waste compares to other adsorbents. The use of biomass waste as adsorbents is both environmentally and economically advantageous, and it has been discovered to have exceptional color removal capabilities.


Assuntos
Azul de Metileno , Poluentes Químicos da Água , Humanos , Azul de Metileno/química , Adsorção , Cinética , Monitoramento Ambiental , Termodinâmica , Folhas de Planta/química , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Environ Res ; 236(Pt 1): 116692, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37500033

RESUMO

Semiconductor metal oxide with TiO2 nanoparticles removes hazardous compounds from environmental samples. TiO2 nanoparticles have shown potential as an efficient photocatalyst by being employed as a nano-catalyst for the breakdown of organic contaminants in wastewater samples. To separate substances from contaminated samples, combined UV and visible light irradiation has been used. Sol-gel synthesis was used to produce a copper chromite-titanium nanocomposite, which was then evaluated using analytical methods, such as XRD, BET, DRS-UV, and FT-IR. Using visible light, the photocatalytic activity of a nanocomposite made of CuCr2O4 and TiO2 was investigated for its role in the breakdown of malachite green. The effects of several parameters, including pH change, anions presence, contact time, catalyst amount, concentration variation, and the kinetics of photocatalytic degradation were investigated. The magnitude of transition energy calculated using UV-DRS spectra was found to be 3.1 eV for CuCr2O4-TiO2 nanocomposite. Maximum degradation was observed at pH 7.0. The surface area and pore volume of the co-doped samples of Cr2O4 - TiO2 obtained from BET were found to be 6.1213 m2/g and 0.045063 cm3/g respectively. The average particle size of the catalyst of the nano-catalysts calculated from XRD was found to be 8 nm for TiO2 and 66 nm for TiO2-CuCrO4. The peaks obtained in FTIR between the range of 900-500 cm-1 were due to the presence of an aromatic compound. The binding mechanism of a dye molecule to the surface of CuCr2O4-TiO2 nanocomposite was analysed using quantum chemical calculations with the self-consistent reaction field technique employing integral equation formalism for the polarized continuum method and the UFF atomic radii set.


Assuntos
Nanocompostos , Nanopartículas , Titânio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Luz , Água , Nanocompostos/química , Corantes/química , Catálise
18.
Chemosphere ; 335: 139103, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37271472

RESUMO

Metallic nanoparticles (NPs) are of particular interest as antimicrobial agents in water and wastewater treatment due to their broad suppressive range against bacteria, viruses, and fungi commonly found in these environments. This review explores the potential of different types of metallic NPs, including zinc oxide, gold, copper oxide, and titanium oxide, for use as effective antimicrobial agents in water and wastewater treatment. This is due to the fact that metallic NPs possess a broad suppressive range against bacteria, viruses, as well as fungus. In addition to that, NPs are becoming an increasingly popular alternative to antibiotics for treating bacterial infections. Despite the fact that most research has been focused on silver NPs because of the antibacterial qualities that are known to be associated with them, curiosity about other metallic NPs as potential antimicrobial agents has been growing. Zinc oxide, gold, copper oxide, and titanium oxide NPs are included in this category since it has been demonstrated that these elements have antibacterial properties. Inducing oxidative stress, damage to the cellular membranes, and breakdowns throughout the protein and DNA chains are some of the ways that metallic NPs can have an influence on microbial cells. The purpose of this review was to engage in an in-depth conversation about the current state of the art regarding the utilization of the most important categories of metallic NPs that are used as antimicrobial agents. Several approaches for the synthesis of metal-based NPs were reviewed, including physical and chemical methods as well as "green synthesis" approaches, which are synthesis procedures that do not involve the employment of any chemical agents. Moreover, additional pharmacokinetics, physicochemical properties, and the toxicological hazard associated with the application of silver NPs as antimicrobial agents were discussed.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Óxido de Zinco , Antibacterianos/farmacologia , Antibacterianos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias , Cobre/farmacologia , Ouro/farmacologia , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Óxidos/farmacologia , Prata/química , Águas Residuárias , Água/farmacologia , Óxido de Zinco/farmacologia
19.
Cell Biochem Funct ; 41(5): 517-541, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37282756

RESUMO

Hyperglycemia, a distinguishing feature of diabetes mellitus that might cause a diabetic foot ulcer (DFU), is an endocrine disorder that affects an extremely high percentage of people. Having a comprehensive understanding of the molecular mechanisms underlying the pathophysiology of diabetic wound healing can help researchers and developers design effective therapeutic strategies to treat the wound healing process in diabetes patients. Using nanoscaffolds and nanotherapeutics with dimensions ranging from 1 to 100 nm represents a state-of-the-art and viable therapeutic strategy for accelerating the wound healing process in diabetic patients, particularly those with DFU. Nanoparticles can interact with biological constituents and infiltrate wound sites owing to their reduced diameter and enhanced surface area. Furthermore, it is noteworthy that they promote the processes of vascularization, cellular proliferation, cell signaling, cell-to-cell interactions, and the formation of biomolecules that are essential for effective wound healing. Nanomaterials possess the ability to effectively transport and deliver various pharmacological agents, such as nucleic acids, growth factors, antioxidants, and antibiotics, to specific tissues, where they can be continuously released and affect the wound healing process in DFU. The present article elucidates the ongoing endeavors in the field of nanoparticle-mediated therapies for the management of DFU.


Assuntos
Diabetes Mellitus , Pé Diabético , Nanopartículas , Humanos , Pé Diabético/tratamento farmacológico , Cicatrização , Peptídeos e Proteínas de Sinalização Intercelular , Nanopartículas/uso terapêutico , Nanotecnologia , Diabetes Mellitus/tratamento farmacológico
20.
Environ Res ; 232: 116363, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37295587

RESUMO

Due to their widespread occurrence and detrimental effects on human health and the environment, endocrine-disrupting hazardous chemicals (EDHCs) have become a significant concern. Therefore, numerous physicochemical and biological remediation techniques have been developed to eliminate EDHCs from various environmental matrices. This review paper aims to provide a comprehensive overview of the state-of-the-art remediation techniques for eliminating EDHCs. The physicochemical methods include adsorption, membrane filtration, photocatalysis, and advanced oxidation processes. The biological methods include biodegradation, phytoremediation, and microbial fuel cells. Each technique's effectiveness, advantages, limitations, and factors affecting their performance are discussed. The review also highlights recent developments and future perspectives in EDHCs remediation. This review provides valuable insights into selecting and optimizing remediation techniques for EDHCs in different environmental matrices.


Assuntos
Disruptores Endócrinos , Recuperação e Remediação Ambiental , Humanos , Biodegradação Ambiental , Substâncias Perigosas/toxicidade
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