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1.
Sci Rep ; 14(1): 16481, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39013936

RESUMO

Silver-zinc-nickel spinel ferrite was prepared by the co-precipitation procedure with the precise composition Ag0.1Zn0.4Ni0.5Fe2O4 for bolstering pollutant removal effectiveness while upholding magnetic properties and then coated with a mesoporous silica layer. The surface characteristics and composition of Ag0.1Zn0.4Ni0.5Fe2O4@mSiO2 were confirmed using EDX, FT-IR, VSM, XRD, TEM, SEM, and BET methods. The surface modification of Ag-Zn-Ni ferrite with a silica layer improves the texture properties, where the specific surface area and average pore size of the spinel ferrite rose to 180 m2/g and 3.15 nm, respectively. The prepared spinel ferrite@mSiO2 has been utilized as an efficient adsorbent for eliminating methyl green (MG) and indigo carmine (IC) as models of cationic and anionic dyes from wastewater, respectively. Studying pH, Pzc, adsorbent dosage, dye concentration, and temperature showed that efficient removal of MG was carried out in alkaline media (pH = 12), while the acid medium (pH = 2) was effective for IC removal. Langmuir isotherm and pseudo-second-order kinetics were found to be good fits for the adsorption data. Both dyes were adsorbed in a spontaneous, endothermic process. A possible mechanism for dye removal has been proposed. The adsorbent was effectively recovered and reused.

2.
Int J Biol Macromol ; 233: 123562, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36750169

RESUMO

The development of effective and economical technologies for the treatment of contaminated wastewater has been of great significance to researchers. Therefore, an equal molar ratio of iron and zinc oxides nanoparticles was hydrothermally immobilized on the cellulose fibers of rice husk. Using XRD, SEM, FTIR, EDX, TEM, VSM, BET, and TGA/DTG, the structure, and characteristics of Cel/α-Fe2O3-ZnO, a ternary nanocomposite, were affirmed. The nanocomposite displayed a mesoporous structure with a substantial surface area. The efficiency of nanocomposite as a new adsorbent has been studied for the extraction of reactive black 5 (RB5), which is a diazo-anionic dye from simulated wastewater. The medium's pH was the dominant factor of RB5 adsorption, and the optimal removal effectiveness was acquired at pH 2. The adsorption values of RB5 correspond to second-order kinetics. They also matched Langmuir with a maximum capacity of 99.30 mg g-1. For real industrial wastewater, Cel/α-Fe2O3-ZnO has successfully reduced a number of major pollutants, including ammonia (92.73 %), color (92.88 %), COD (91.53 %), BOD5 (84.97 %), TSS (96.27 %), TP (52.17 %) and TN (47.23 %). These results illustrate the effective application of the ternary nanocomposite in wastewater treatment.


Assuntos
Nanocompostos , Nanopartículas , Oryza , Poluentes Químicos da Água , Óxido de Zinco , Óxido de Zinco/química , Águas Residuárias , Ferro , Celulose , Adsorção , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Nanocompostos/química
3.
Oxid Med Cell Longev ; 2021: 8511576, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707782

RESUMO

The present research displays the green synthesis of stable silver nanoparticles (AgNPs). The aqueous solution of Fucoidan from Fucus vesiculosus source (brown marine algae) is used as a reducing and capping agent. UV-Vis spectroscopy, XRD, FT-IR, SEM, EDX, and TEM with selected area electron diffraction are used to characterize the synthesized silver nanoparticles (AgNPs). The synthesized AgNPs exhibit a surface plasmon resonance at 430 nm after 24 h. The characterization results showed that AgNPs are crystalline in nature and exhibit mostly spherical shapes with an average diameter of 4-45 nm. Silver nanoparticles showed effective antibacterial activity against representative pathogens of bacteria. The activities of commercial antibiotics were enhanced by impregnation with the synthesized AgNPs. It also shows good fungicidal and anticancer activity against liver and lung cell lines and shows significant antioxidant efficacy (84%) at 10 µg/ml AgNP concentration against DPPH. The utilization of environmentally synthesized AgNPs offers numerous benefits of ecofriendliness and compatibility for biomedical applications.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Nanopartículas Metálicas , Polissacarídeos/farmacologia , Nitrato de Prata/farmacologia , Células A549 , Antibacterianos/química , Antineoplásicos/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Compostos de Bifenilo/química , Sobrevivência Celular/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Composição de Medicamentos , Sequestradores de Radicais Livres/química , Química Verde , Células Hep G2 , Humanos , Nanotecnologia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Picratos/química , Polissacarídeos/química , Nitrato de Prata/química
4.
J Environ Manage ; 288: 112481, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33827021

RESUMO

In this study, chitosan (CS) is used as a natural coagulant aid alongside graphene oxide (GO) to remove turbidity and numerous pollutants from raw and artificially contaminated surface water. The coagulation capability of the system (GO/CS) was assessed with respect to a water sample's turbidity, pH, coagulant dose, settling velocity, and temperature. The presence of CS enhanced the coagulation capacity of GO at varied pH levels and no GO residue was detected in the water after the treatment. The proposed system achieved high turbidity removal efficiency (≥98.3%) for all turbidity levels. A mixture of GO (8 mg/L) and CS (2 mg/L) was ideal to remove algae (99.5%) and bacteria (≥95.0%). Furthermore, it demonstrated a high coagulation capacity to remove dyes, direct brown-2 (DB-2), methylene blue (MB), and Pb(II) ions from artificially contaminated surface water. Interestingly, the sludge exhibited an extraordinary adsorption capacity for DB-2, MB, and Pb(II) ions. The adsorption process followed the pseudo-second-order kinetic model, and was consistent with the Langmuir model, with an adsorption capacity of up to 667.8, 400.7, and 459.1 mg/g for DB-2, MB, and Pb(II) ions, respectively. Therefore, the presented binary coagulation system is of great potential economic value for the treatment of raw surface water and wastewater.


Assuntos
Quitosana , Grafite , Poluentes Químicos da Água , Purificação da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
5.
Artigo em Inglês | MEDLINE | ID: mdl-33573579

RESUMO

The article has been withdrawn on the recommendation of the Editor-in-Chief of the journal Anti-Cancer Agents in Medicinal Chemistry due to some inconsistencies in the content of the article. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policiesmain.php Bentham Science Disclaimer: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

6.
Environ Monit Assess ; 192(6): 355, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32394116

RESUMO

This study reveals the feasibility of exploring highly efficient, cost-effective, and stable green adsorbents for the treatment of contaminated water. Here silver nanoparticles (AgNPs) were immobilized onto nanosheets of graphene oxide (GO) through in situ reduction process using green tea aqueous extract. GO reduction to reduced graphene oxide (rGO) and AgNPs decoration on rGO also occurred simultaneously. The impacts of the extract concentration, contact time, and temperature on the synthesis process have been investigated. The synthesized nanocomposites were examined by XRD, FTIR, Raman, SEM, TEM, and TGA. The GO nanosheets were decorated by AgNPs with a crystalline structure and an average particle size of 25 ± 3 nm. The temperature and the extract concentration were considerably affecting the type of the resulting nanocomposites. The GO/Ag nanocomposites were formed at room temperature (27 °C) using different extract concentration (2-18% (v/v)), while the rGO/Ag nanocomposite was formed only at a higher temperature (95 °C) with higher extract concentration (18%). The methylene blue (MB) dye was picked as a water pollutant to explore the adsorption ability of the nanocomposites. The adsorption behavior of the GO/Ag nanocomposites was examined under diverse factors (MB concentration, adsorbent dosage, pH, and contact time) to achieve optimization. The adsorption data concurs with Langmuir isotherm giving maximum adsorption up to 633 mg g-1. Adsorption kinetics demonstrate good pseudo-second-order compliance. Spontaneous and endothermic nature of adsorption was affirmed via thermodynamic parameters. The nanocomposites could be utilized as eco-friendly and reliable adsorbents in wastewater treatment, as a result of their exceptional productivity and reusing potential.


Assuntos
Grafite , Nanopartículas Metálicas , Azul de Metileno , Nanocompostos , Poluentes Químicos da Água , Adsorção , Cinética , Prata
7.
Int J Biol Macromol ; 116: 1250-1259, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29791874

RESUMO

A green electrospinning was used for the fabrication of PVA/Dex (dextran sulfate) nanofibers as a carrier for drug delivery. Core-shell nanofibers were fabricated by emulsion electrospinning from PVA/Dex loaded with ciprofloxacin (Cipro) as a model drug. The ratio of the PVA/Dex mixture was optimized and nanofibers were stabilized against disintegration in water by thermal treatment at 120 °C. The morphology of the prepared nanofibers was observed by scanning electron microscopy (SEM) and the core-shell structure of the nanofibers was confirmed by transmission electron microscopy (TEM). Drug entrapment was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The interaction between PVA and Dex was affirmed by differential scanning calorimetry (DSC). In vitro drug release was monitored by UV-vis spectrophotometer and its associated mechanism was studied using diverse kinetic models. The release study demonstrated that the core-shell nanofibers can sustain the Cipro release compared with the blending electrospinning nanofibers. Moreover, the drug release mechanism is controlled by the Dex content of the polymer blends and can occur by diffusion within the delivery system. It is anticipated that Cipro@PVA/Dex nanofibers are promising eco-friendly drug delivery system which can be prepared by a green method.


Assuntos
Ciprofloxacina , Dextranos , Sistemas de Liberação de Medicamentos/métodos , Nanofibras/química , Álcool de Polivinil , Ciprofloxacina/química , Ciprofloxacina/farmacocinética , Dextranos/química , Dextranos/farmacocinética , Emulsões , Nanofibras/ultraestrutura , Álcool de Polivinil/química , Álcool de Polivinil/farmacocinética
8.
Environ Monit Assess ; 189(7): 349, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28646435

RESUMO

Stable colloidal silver nanoparticles (AgNPs) were synthesized using Caulerpa serrulata (green marine algae) aqueous extract as an efficient reducing and stabilizing agent. This method is considered to be a sustainable alternate to the more complicated chemical procedures. To achieve the optimization synthesis of AgNPs, several effects such as extract concentration, contact time, pH values, and temperature were examined. The synthesized AgNPs were characterized by UV-Vis spectroscopy, FT-IR, XRD, and HR-TEM. The synthesized AgNPs showed an intense surface plasmon resonance band at 412 nm at the optimal conditions (20% (v/v) extract and 95 °C). TEM reveal that higher extract concentration and higher temperature leading to the formation of spherical AgNPs with an average particle size of 10 ± 2 nm. The synthesized AgNPs showed excellent catalytic reduction activity of Congo red (CR) dye from aqueous solutions. The degradation percentage of CR with AgNPs accelerated by increasing either NaBH4 concentration or catalytic dosage. The AgNPs synthesized at higher temperature (e.g., 10Ag-95) exhibited the highest catalytic activity. The reaction kinetics was found to be pseudo first order with respect to the dye concentration. Moreover, the AgNPs displayed antibacterial activity at lower concentration against Staphylococcus aureus, Pseudomonas aeruginosa, Shigella sp., Salmonella typhi, and Escherichia coli and may be a good alternative therapeutic approach. The outcomes of the current study confirmed that the synthesized AgNPs had an awesome guarantee for application in catalysis and wastewater treatment.


Assuntos
Antibacterianos/metabolismo , Caulerpa/metabolismo , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/farmacologia , Catálise , Monitoramento Ambiental , Escherichia coli/efeitos dos fármacos , Tamanho da Partícula , Extratos Vegetais/química , Pseudomonas aeruginosa , Prata/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Ressonância de Plasmônio de Superfície
9.
Chemosphere ; 181: 738-746, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28478234

RESUMO

This study presents the performance of graphene oxide (GO) as a coagulant in turbidity removal from naturally and artificially turbid raw surface water. GO is considered an excellent alternative to alum, the more common coagulant used in water treatment processes, to reduce the environmental release of aluminum. Effects of GO dosage, pH, and temperature on its coagulation ability were studied to determine the ideal turbidity removal conditions. The turbidity removal was ≥95% for all levels of turbid raw surface water (20, 100, and 200 NTU) at optimum conditions. The role of alkalinity in inducing turbidity removal by GO coagulation was much more pronounced upon using raw surface water samples compared with that using artificially turbid deionized water samples. Moreover, GO demonstrated high-performance removal of biological contaminants such as algae, heterotrophic bacteria, and fecal coliform bacteria by 99.0%, 98.8% and 96.0%, respectively, at a dosage of 40 mg/L. Concerning the possible environmental release of GO into the treated water following filtration process, there was no residual GO in a wide range of pH values. The outcomes of the study highlight the excellent coagulation performance of GO for the removal of turbidity and biological contaminants from raw surface water.


Assuntos
Grafite/química , Óxidos/química , Purificação da Água/métodos , Alumínio/isolamento & purificação , Bactérias/isolamento & purificação , Clorófitas , Filtração , Concentração de Íons de Hidrogênio , Temperatura , Água/análise
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