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1.
Chemosphere ; 337: 139342, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37392798

RESUMEN

In this work, magnesium oxide nanoparticles supported biochar derived from tea wastes (MgO@TBC) was prepared as an effective adsorbent for removing hazardous o-chlorophenol (o-CP) from industrial wastewater. The surface area, porous structure, surface functional groups and surface charge of tea waste biochar (TBC) significantly enhanced after the modification process. The best uptake performance of o-CP was found at pH = 6.5 and 0.1 g of MgO@TBC adsorbent. According to the adsorption isotherm, the adsorption of o-CP onto MgO@TBC followed the Langmuir model with a maximum uptake capacity of 128.7 mg/g, which was 26.5% higher than TBC (94.6 mg/g). MgO@TBC could be reused for eight cycles with a high o-CP uptake performance (over 60%). Besides, it also exhibited good removal performance of o-CP from industrial wastewater with a removal rate of 81.7%. The adsorption behaviors of o-CP onto MgO@TBC are discussed based on the experimental results. This work may provide information to prepare an effective adsorbent for removing hazardous organic contaminants in wastewater.


Asunto(s)
Nanopartículas , Contaminantes Químicos del Agua , Óxido de Magnesio/química , Aguas Residuales , Adsorción , Cinética , Contaminantes Químicos del Agua/análisis , Carbón Orgánico/química ,
2.
Sci Total Environ ; 890: 164084, 2023 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-37207781

RESUMEN

Struvite precipitation is a well-known technology to recover and upcycle phosphorus from municipal wastewater as a slow-release fertiliser. However, the economic and environmental costs of struvite precipitation are constrained by using technical-grade reagents as a magnesium source. This research evaluates the feasibility of using a low-grade magnesium oxide (LG-MgO) by-product from the calcination of magnesite as a magnesium source to precipitate struvite from anaerobic digestion supernatants in wastewater treatment plants. Three distinct LG-MgOs were used in this research to capture the inherent variability of this by-product. The MgO content of the LG-MgOs varied from 42 % to 56 %, which governed the reactivity of the by-product. Experimental results showed that dosing LG-MgO at P:Mg molar ratio close to stoichiometry (i.e. 1:1 and 1:2) favoured struvite precipitation, whereas higher molar ratios (i.e. 1:4, 1:6 and 1:8) favoured calcium phosphate precipitation due to the higher calcium concentration and pH. At a P:Mg molar ratio of 1:1 and 1:2, the percentage of phosphate precipitated was 53-72 % and 89-97 %, respectively, depending on the LG-MgO reactivity. A final experiment was performed to examine the composition and morphology of the precipitate obtained under the most favourable conditions, which showed that (i) struvite was the mineral phase with the highest peaks intensity and (ii) struvite was present in two different shapes: hopper and polyhedral. Overall, this research has demonstrated that LG-MgO is an efficient source of magnesium for struvite precipitation, which fits the circular economy principles by valorising an industrial by-product, reducing the pressure on natural resources, and developing a more sustainable technology for phosphorus recovery.


Asunto(s)
Óxido de Magnesio , Purificación del Agua , Estruvita/química , Óxido de Magnesio/química , Magnesio/química , Compuestos de Magnesio/química , Anaerobiosis , Fosfatos/química , Fósforo/química , Precipitación Química , Eliminación de Residuos Líquidos/métodos
3.
Molecules ; 27(16)2022 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-36014400

RESUMEN

The present study describes the green biofunctional synthesis of magnesium oxide (MgO) nanoparticles using the aqueous Tarenna asiatica fruit extract. The characterization of Tarenna asiatica fruit extract MgO nanoparticles (TAFEMgO NPs) was achieved by X-ray powder diffraction, UV-Vis spectroscopy, FTIR, TEM, SEM, and energy-dispersive X-ray diffraction. TAFEMgO NPs scavenged the DPPH free radicals with an IC50 value of 55.95 µg/µL, and it was highly significant compared to the standard. To authenticate the observed antioxidant potential of TAFEMgO NPs, oxidative stress was induced in red blood cells (RBC) using sodium nitrite (NaNO2). Interestingly, TAFEMgO NPs ameliorated the RBC damage from oxidative stress by significantly restoring the stress parameters, such as the protein carbonyl content (PCC), lipid peroxidation (LPO), total thiol (TT), super-oxide dismutase (SOD), and catalase (CAT). Furthermore, oxidative stress was induced in-vivo in Sprague Dawley female rats using diclofenac (DFC). TAFEMgO NPs normalized the stress parameters in-vivo and minimized the oxidative damage in tissues. Most importantly, TAFEMgO NPs restored the function and architecture of the damaged livers, kidneys, and small intestines by regulating biochemical parameters. TAFEMgO NPs exhibited an anticoagulant effect by increasing the clotting time from 193 s in the control to 885 s in the platelet rich plasma. TAFEMgO NPs prolonged the formation of the clot process in the activated partial thromboplastin time and the prothrombin time, suggest the effective involvement in both intrinsic and extrinsic clotting pathways of the blood coagulation cascade. TAFEMgO NPs inhibited adenosine di-phosphate (ADP)-induced platelet aggregation. TAFEMgO NPs did not show hemolytic, hemorrhagic, and edema-inducing properties at the tested concentration of 100 mg/kgbody weight, suggesting its non-toxic property. In conclusion, TAFEMgO NPs mitigates the sodium nitrite (NaNO2)- and diclofenac (DFC)-induced stress due to oxidative damage in both in vitro and in vivo experimental models.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Trombosis , Animales , Diclofenaco/farmacología , Femenino , Óxido de Magnesio/química , Óxido de Magnesio/farmacología , Nanopartículas del Metal/química , Nanopartículas/química , Estrés Oxidativo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Carbonilación Proteica , Ratas , Ratas Sprague-Dawley , Nitrito de Sodio/farmacología
4.
Biomater Adv ; 138: 212855, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35913247

RESUMEN

The use of chemically synthesized nanoparticles and crude plant extracts as antimicrobial -anticancer agents have many limitations. In this study, we have used Centella asiatica extract (CaE) having relatively less explored but tremendous medicinal properties, as reducing and stabilizing agents to green synthesize magnesium oxide nanoparticles (MgONPs) using magnesium nitrate. In comparison to the bulk material, capabilities of Ca-MgONPs as an improved antibacterial, antifungal, and anticancer agent in human prostatic carcinoma cells (PC3), as well as membranolytic capability in model cell membrane, were studied. The phyto-functionalized Ca-MgONPs were characterized using UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDX), X-ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FT-IR) and Atomic Force Microscopy (AFM). Observation of characteristic peaks by spectroscopic and microscopic analysis confirmed the synthesis of Ca-MgONPs. The Ca-MgONPs showed broad spectrum of bactericidal activity against both gram-positive and gram-negative bacteria and fungicidal activity against two species of the Candida fungus. The Ca-MgONPs also exhibited dose-dependent and selective inhibition of proliferating PC3 cells with IC50 of 123.65 ± 4.82 µg/mL at 24 h, however, without having any cytotoxicity toward non-cancerous HEK293 cells. Further studies aimed at understanding the probable mechanism of toxicity of Ca-MgONPs in PC3 cells, the results indicated a significant reduction in cell migration capacities, increment in cytosolic ROS, loss of mitochondrial transmembrane potential, DNA damage and S-phase cell cycle arrest. Ca-MgONPs also induced pore formation in a synthetic large unilamellar vesicle. Thus, Ca-MgONPs might be useful in the effective management of several human pathogens of concern and some more cancer types.


Asunto(s)
Antiinfecciosos , Centella , Nanopartículas del Metal , Antibacterianos/farmacología , Antiinfecciosos/química , Bacterias Gramnegativas , Bacterias Grampositivas , Tecnología Química Verde , Células HEK293 , Humanos , Óxido de Magnesio/química , Nanopartículas del Metal/uso terapéutico , Extractos Vegetales , Espectroscopía Infrarroja por Transformada de Fourier , Triterpenos
5.
Proc Natl Acad Sci U S A ; 119(30): e2202682119, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35858430

RESUMEN

Heterogeneous peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have shown a great potential for pollutant degradation, but their feasibility for large-scale water treatment application has not been demonstrated. Herein, we develop a facile coprecipitation method for the scalable production (∼10 kg) of the Cu-Fe-Mn spinel oxide (CuFeMnO). Such a catalyst has rich oxygen vacancies and symmetry-breaking sites, which endorse it with a superior PMS-catalytic capacity. We find that the working reactive species and their contributions are highly dependent on the properties of target organic pollutants. For the organics with electron-donating group (e.g., -OH), high-valent metal species are mainly responsible for the pollutant degradation, whereas for the organics with electron-withdrawing group (e.g., -COOH and -NO2), hydroxyl radical (•OH) as the secondary oxidant also plays an important role. We demonstrate that the CuFeMnO-PMS system is able to achieve efficient and stable removal of the pollutants in the secondary effluent from a municipal wastewater plant at both bench and pilot scales. Moreover, we explore the application prospect of this PMS-based AOP process for large-scale wastewater treatment. This work describes an opportunity to scalably prepare robust spinel oxide catalysts for water purification and is beneficial to the practical applications of the heterogeneous PMS-AOPs.


Asunto(s)
Óxido de Aluminio , Óxido de Magnesio , Peróxidos , Contaminantes del Agua , Purificación del Agua , Óxido de Aluminio/química , Catálisis , Óxido de Magnesio/química , Peróxidos/química , Contaminantes del Agua/química , Purificación del Agua/métodos
6.
Chemosphere ; 303(Pt 1): 135011, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35609664

RESUMEN

Each year, extensive dredged clay slurries containing heavy metals need to be treated before being reused; in such contaminated slurries, lead (Pb) is frequently identified. Quicklime (CaO)-activated ground granulated blast-furnace slag (GGBS), magnesium (MgO)-activated GGBS, and ordinary Portland cement (OPC) are usually used to remediate the lead (Pb)-contaminated soil; nevertheless, using these curing agents (or binders), particularly CaO-GGBS and MgO-GGBS, to treat Pb-contaminated slurry with high water content is rarely reported. Moreover, inconsistent results were obtained from previous studies in terms of the mechanical and leaching performance of Pb-contaminated soils with the three binders. Based on the above-mentioned reasons, this study used CaO-GGBS, MgO-GGBS, and OPC to treat the Pb-contaminated clay slurry, and compared the effectiveness of the three binders in improving the mechanical and leaching properties of the slurry. Laboratory tests were performed to examine the leaching, strength, mineralogical, and micro-structural performance of treated clay slurries. The results showed that GGBS-based binders were more effective than OPC in improving the strength and Pb leachability of contaminated slurries. When suitable ratios between activators (CaO and MgO) and GGBS were used, a similar or even higher UCS was produced by CaO-GGBS than MgO-GGBS. Similar leachate pH and Pb leachability could be achieved between CaO-GGBS- and MgO-GGBS-treated contaminated clay slurries. Therefore, it is not rigorous to state that MgO-GGBS is better in improving the strength and leachability of Pb-contaminated soils than CaO-GGBS only by comparing the two GGBS-binders based on the same activator/GGBS ratio, as reported in some previous studies. The leachability of Pb was affected by the pH, but the addition of GGBS facilitated the decrease of Pb leachability in slurries. The XRD result showed the formation of CSH and Pb(OH)2, which facilitated the reduction of Pb leachability.


Asunto(s)
Contaminantes del Suelo , Arcilla , Plomo , Óxido de Magnesio/química , Suelo/química , Contaminantes del Suelo/análisis
7.
Chemosphere ; 296: 133878, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35131268

RESUMEN

The low cost and non-toxic of magnesium oxides make it a potential eco-friendly material for arsenic removal. Polysaccharide is a kind of green modifier to obtain nanoscale MgO particles with a higher adsorption affinity. In this study, the impact of chain structures of polysaccharides on the morphology features and arsenate removal efficiency of MgO-NPs were investigated. Pullulan and starch facilitated the synthesis of flower-like MgO-NPs, and pectin facilitated the synthesis of plate-like ones. Although the two kinds of flower-like MgO-NPs undergone similar time to reach equilibrium, the one obtained from the starch-synthesis route showed a higher arsenate adsorption capacity (98 mg g-1), due to that their bushy and smaller petals on the surface provide more active sites for arsenic adsorption. The pectin-synthesis route also produced MgO-NPs with higher arsenate adsorption capacity (101 mg g-1), ascribed to stacking of nano-plates on their surfaces facilitated to form defect surfaces. However, due to their lower BET area, the plate-like MgO-NPs took twice times to reach equilibrium for arsenic adsorption compared with the others. In the stage for the hydrolysis of MgO, hydroxyl groups on the polymer chain provide active sites to physically trap or bond with MgO particles and then to produce hydrolyzed precursors. The poly chain containing inter- and intra-hydroxyl groups directed MgO molecular growing into hydroxide crystals with 3D frameworks during their nucleation and growth. However, pectin only provides inter-hydroxyl groups and directs to form hydroxides with 2D frameworks. Furthermore, the rapid-nucleation vs. slow-growth model in the stage of pyrolysis of hydroxide crystals successfully interprets the thinner petals and complex chemical phases of the final nanoparticles obtained from the pullulan-synthesis route. This work may provide direction and perspectives for the rational design of well-performing MgO materials for arsenate removal.


Asunto(s)
Arsénico , Nanopartículas , Contaminantes Químicos del Agua , Adsorción , Arseniatos , Óxido de Magnesio/química , Nanopartículas/química , Pectinas , Polisacáridos , Almidón , Contaminantes Químicos del Agua/análisis
8.
Food Chem Toxicol ; 159: 112725, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34856315

RESUMEN

Synthetic food colorants are extensively used across the globe regardless of the fact that they induce deleterious side effects when used in higher amounts. In this work, a novel electrochemical sensor based on nickel nanoparticles doped lettuce-like Co3O4 anchored graphene oxide (GO) nanosheets was developed for effective detection of sulfonated azo dye sunset yellow widely used as a food colorant. Hydrothermal synthesis was adopted for the preparation of lettuce-like spinel Co3O4 nanoparticles and Ni-Co3O4 NPs/GO nanocomposite was prepared using ecofriendly and economical sonochemical method. The prepared ternary nanocomposite meticulously fabricated on a screen-printed carbon electrode exhibited remarkable electrocatalytic activity towards sunset yellow determination. This is apparent from the resultant well-defined and intense redox peak currents of Ni-Co3O4 NPs/GO nanocomposite modified electrode at very low potentials. The developed sunset yellow sensor exhibited a high sensitivity of 4.16 µA µM-1 cm-2 and a nanomolar detection limit of 0.9 nM in the linear range 0.125-108.5 µM. Furthermore, experiments were conducted to affirm excellent stability, reproducibility, repeatability, and selectivity of proposed sensor. The practicality of sunset yellow determination using the developed sensor was analyzed in different varieties of food samples including jelly, soft drink, ice cream, and candy resulting in recovery in the range of 96.16%-102.56%.


Asunto(s)
Compuestos Azo/análisis , Técnicas Electroquímicas/métodos , Colorantes de Alimentos/análisis , Nanopartículas del Metal/química , Nanocompuestos/química , Óxido de Aluminio/química , Cobalto/química , Grafito , Límite de Detección , Modelos Lineales , Óxido de Magnesio/química , Níquel/química , Óxidos/química , Reproducibilidad de los Resultados
9.
Molecules ; 26(19)2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34641609

RESUMEN

In recent years, the interest in the health-promoting effects of hop prenylflavonoids, especially its estrogenic effects, has grown. Unfortunately, one of the most potent phytoestrogens identified so far, 8-prenylnaringenin, is only a minor component of hops, so its isolation from hop materials for the production of estrogenically active food supplements has proved to be problematic. The aim of this study was to optimize the conditions (e.g., temperature, the length of the process and the amount of the catalyst) to produce 8-prenylnaringenin-rich material by the magnesium oxide-catalyzed thermal isomerization of desmethylxanthohumol. Under these optimized conditions, the yield of 8-prenylnaringenin was 29 mg per 100 gDW of product, corresponding to a >70% increase in its content relative to the starting material. This process may be applied in the production of functional foods or food supplements rich in 8-prenylnaringenin, which may then be utilized in therapeutic agents to help alleviate the symptoms of menopausal disorders.


Asunto(s)
Flavanonas/metabolismo , Flavonoides/metabolismo , Fitoestrógenos/metabolismo , Preparaciones de Plantas/metabolismo , Propiofenonas/metabolismo , Cerveza/análisis , Catálisis , Suplementos Dietéticos/análisis , Flavanonas/química , Flavonoides/química , Humanos , Humulus/química , Óxido de Magnesio/química , Óxido de Magnesio/metabolismo , Fitoestrógenos/química , Extractos Vegetales/metabolismo , Preparaciones de Plantas/química , Propiofenonas/química , Temperatura
10.
Molecules ; 26(4)2021 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-33562208

RESUMEN

MgAl2O4-spinel has wide industrial and geological applications due to its special structural and physical-chemical features. It is presumably the most important endmember of complex natural spinel solid solutions, and therefore provides a structural model for a large group of minerals with the spinel structure. There exists a well known but still inadequately understood phenomenon in the structure of MgAl2O4-spinel, the Mg-Al cations readily exchanging their positions in response to variations of temperature, pressure, and composition. A large number of experiments were performed to investigate the Mg-Al cation order-disorder process usually quantified by the inversion parameter x (representing either the molar fraction of Al on the tetrahedral T-sites or the molar fraction of Mg on the octahedral M-sites in the spinel structure), and some thermodynamic models were thereby constructed to describe the x-T relation. However, experimental data at some key T were absent, so that the different performance of these thermodynamic models could not be carefully evaluated. This limited the interpolation and extrapolation of the thermodynamic models. By performing some prolonged annealing experiments with some almost pure natural MgAl2O4-spinel plates and quantifying the x values with single-crystal X-ray diffraction technique, we obtained some critical equilibrium x values at T down to 773 K. These new x-T data, along with those relatively reliable x values at relatively high T from early studies, clearly indicate that the CS94 Model (a model constructed by Carpenter and Salje in 1994) better describes the Mg-Al cation order-disorder reaction in MgAl2O4-spinel for a wide range of T. On the basis of the CS94 Model, a geothermometer was established, and its form is T-closure = 21362 × x3 - 12143 × x2 + 6401 × x - 10 (T-closure standing for the closure temperature of the Mg-Al cation exchange reaction). This geothermometer can be used to constrain the thermal history of the geological bodies containing MgAl2O4-spinel.


Asunto(s)
Aluminio/química , Magnesio/química , Óxidos/química , Óxido de Aluminio/química , Óxido de Magnesio/química , Minerales/química , Modelos Moleculares , Soluciones/química , Temperatura , Termodinámica , Difracción de Rayos X
11.
PLoS One ; 15(8): e0237567, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32797097

RESUMEN

Distinct morphological MgO nanoparticles (MgONPs) were synthesized using biomasses of Saussurea costus roots. The biomass of two varieties of Saussurea costus (Qustal hindi and Qustal bahri) were used in the green synthesis of MgONPs. The physical and chemical features of nanoparticles were confirmed by spectroscopic and microscopic techniques. The surface morphology of the obtained nanoparticles was detected at different magnifications by SEM and TEM microscopy and the size of nanoparticles were found to be 30 and 34 nm for Qustal hindi and Qustal bahri, respectively. The antimicrobial activity of the prepared MgONPs was screened against six pathogenic strains. The synthesized nanoparticles by Qustal bahri biomass exerted significant inhibition zones 15, 16, 18, 17, 14, and 10 mm against E. coli, P. aeruginosa, C. tropicalis and C. glabrata, S. aureus and B. subtilis as compared to those from Qustal hindi 12, 8 and 17 mm against B. subtilis, E. coli and C. tropicalis, respectively. MgONPs showed a potential cytotoxicity effect against MCF-7 breast cancer cell lines. Cellular investigations of MgONPs revealed that the prepared nanoparticles by Qustal bahri exhibited high cytotoxicity against MCF-7 cancer cell lines. IC50 values in MCF-7 cells were found to be 67.3% and 52.1% for MgONPs of Saussurea costus biomasses, respectively. Also, the photocatalytic activity of MgONPs of each Saussurea costus variety was comparatively studied. They exhibited an enhanced photocatalytic degradation of methylene blue after UV irradiation for 1 h as 92% and 59% for those prepared by Qustal bahri and Qustal hindi, respectively. Outcome of results revealed that the biosynthesized MgONPs showed promising biomedical potentials.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Óxido de Magnesio/farmacología , Azul de Metileno/química , Saussurea/química , Antiinfecciosos/química , Antineoplásicos/química , Bacterias/efectos de los fármacos , Biomasa , Catálisis , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Hongos/efectos de los fármacos , Tecnología Química Verde , Humanos , Células MCF-7 , Óxido de Magnesio/química , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana , Procesos Fotoquímicos , Extractos Vegetales/química , Raíces de Plantas/química
12.
Chemosphere ; 259: 127427, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32599385

RESUMEN

Spinel oxides, e.g., NiCo2O4, is a promising catalyst for the catalytic oxidation of toluene. Understanding and designing versatile NiCo2O4 spinel is important for low-temperature toluene oxidation. Here, we investigated the surface-characteristic-dependent degradation activity of NiCo2O4 crystals through experiment and characterization. NiCo2O4 nanosheet using ethanol as solvent (named E--NiCo2O4) exposing {110} crystal planes exhibited the lowest temperature toluene oxidation. The T99 of toluene conversion was 256 °C, which is much lower than that of NiCo2O4 nanosheet using ethylene glycol as solvent (named EG--NiCo2O4), NiCo2O4 octahedron (named O--NiCo2O4) and NiCo2O4 truncated octahedron (named TO--NiCo2O4). Characterization using various techniques such as XRD, TEM, BET, XPS, H2-TPR and CO2-TPD showed that Co3+ and surface adsorbed oxygen (Osur) enriched surface, excellent redox properties and effective diffusion of the reaction product reasonably explain the enhancement in catalytic activity over the E--NiCo2O4. The research reveals that the effect of specific crystal planes and solvent was the key factor to govern the activity of low-temperature toluene oxidation.


Asunto(s)
Óxido de Aluminio/química , Óxido de Magnesio/química , Tolueno/química , Adsorción , Catálisis , Frío , Oxidación-Reducción , Óxidos/química , Oxígeno/química , Solventes
13.
Ecotoxicol Environ Saf ; 194: 110384, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32126412

RESUMEN

Electrolytic manganese residue (EMR) contains a large amount of NH4+-N and Mn2+ and can negatively impact the environment. A stabilization treatment of soluble contaminants in the EMR is necessary for its reuse and safe stacking. This study presents experimental results for the stabilization of NH4+-N and Mn2+ in the EMR using phosphogypsum leachate as a low-cost phosphate source and MgO/CaO (PLMC) process. The results demonstrated that the stabilization efficiency of NH4+-N and Mn2+ was 93.65% and 99.99%, respectively, under the following conditions: a phosphogypsum leachate dose of 1.5 mL g-1, an added MgO dose of 0.036 g g-1, an added CaO dose of 0.1 g g-1 and a reaction time of 2 h. The stabilization effect of the PLMC process was higher and more cost effective than that of using Na3PO4·12H2O and MgO/CaO. The concentration of NH4+-N and Mn2+ in the leaching liquor decreased to 80 mg L-1 and 0.5 mg L-1, respectively, after the stabilization under the optimum conditions. The stabilization characteristics indicated that NH4+-N was stabilized to form NH4MgPO4·6H2O (struvite) and that Mn2+ was stabilized to form Mn5(PO4)2(OH)4, Mn3(PO4)2·3H2O and Mn(OH)2. PO43--P, F-, and heavy metal ions of the phosphogypsum leachate were removed from the leaching liquor and stabilized in the treated EMR.


Asunto(s)
Compuestos de Calcio/química , Sulfato de Calcio/química , Óxido de Magnesio/química , Manganeso/análisis , Óxidos/química , Fósforo/química , Amoníaco/análisis , Amoníaco/química , Electrólisis , Electrólitos , Contaminantes Ambientales/análisis , Contaminantes Ambientales/química , Residuos Industriales/análisis , Manganeso/química , Solubilidad , Estruvita/análisis , Estruvita/química
14.
Chemosphere ; 247: 125847, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32069709

RESUMEN

The effective removal and recovery of phosphorus from aquatic environments are highly important for successful eutrophication control and phosphorus recycling. Herein, we prepared biochar containing MgO nanoparticles (MgO-biochar) by fast pyrolysis of MgCl2-impregnated corn stalks, probed its phosphate adsorption performance. Through the fast pyrolysis, the MgCl2 promoted the formation of micropores and mesoporous, and decomposed into MgO nanoparticles with the size smaller than 100 nm. The adsorption experiments showed that the adsorption property increased with the increase of Mg content, and had a strong correlation with the external surface area. And the phosphate adsorption was well described by the Langmuir-Freundlich model (maximum adsorption capacity was determined as 60.95 mg P/g). Kinetic analysis and characterization analysis of MgO-biochar for different adsorption time indicated that phosphate adsorption onto MgO-biochar was mainly controlled by rapid binding to the external surface (about 75% of the equilibrium adsorption amount), and the uptake rate was limited by the slow diffusion of phosphate into the biochar interior (about 25% of the equilibrium adsorption amount). The results suggested that the synthesized MgO-biochar with enough MgO active site dispersed on a higher external surface can be used as a potential adsorbent for phosphate removal and recovery from aqueous solution.


Asunto(s)
Carbón Orgánico/síntesis química , Óxido de Magnesio/química , Fósforo/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Cinética , Nanopartículas/química , Fosfatos/química , Fósforo/química , Reciclaje , Agua , Contaminantes Químicos del Agua/análisis
15.
Chemosphere ; 242: 125244, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31896184

RESUMEN

Efficient wastewater restoration depends on the robustness and capability of the catalyst to promote sophisticated decontamination technologies. In this study, Co3Fe7-CoFe2O4 nanoparticles (NPs) prepared by facile pyrolysis were completely characterized and used to decompose 2,4-dichlorophenol (2,4-DCP). Furthermore, the catalytic performance and relevant mechanisms involved in the activation of peroxymonosulfate (PMS) were also investigated. The optimal conditions were achieved at the catalyst loading of 0.05 g L-1, PMS dosage of 1.26 g L-1, and pH of 7.7 through the response surface methodology by using the Box-Behnken design model. Under optimal conditions, 97.1% efficiency of 2,4-DCP removal was obtained within 30 min. Moreover, the quenching experiments and electron paramagnetic resonance result indicated that sulfate (SO4•-) and hydroxyl (HO•) radicals were considered as the dominant reactive oxygen species, which resulted in the effective removal of 2,4-DCP in the Co3Fe7-CoFe2O4/PMS system. Moreover, Co3Fe7-CoFe2O4 showed efficient catalytic performance in continuous five runs and exhibited less metal leaching of 0.052 and 0.036 mg L-1 for Co and Fe species, respectively. Furthermore, no considerable change was observed in the structural characteristics of the fresh and used Co3Fe7-CoFe2O4 catalytic system. The above-mentioned results indicated that the synergistic effects between Co3Fe7 alloy and CoFe2O4 spinel not only significantly improved the activity and long-term durability of the catalyst, but also accelerated the Co3+/Co2+ and Fe3+/Fe2+ redox cycles. Overall, the Co3Fe7-CoFe2O4/PMS system provides a novel advanced oxidation approach to further develop multifunctional transition metal-based nanomaterials responsible for producing surface-bound radicals and enhancing the remediation of refractory pollutants in the environmental application.


Asunto(s)
Óxido de Aluminio/química , Clorofenoles/química , Óxido de Magnesio/química , Peróxidos/química , Eliminación de Residuos Líquidos/métodos , Aleaciones , Catálisis , Nanopartículas/química , Oxidación-Reducción , Fenoles , Aguas Residuales
16.
Appl Biochem Biotechnol ; 190(4): 1385-1410, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31776944

RESUMEN

Insulin resistance is one of the major factors that leads to type 2 diabetes. Although insulin therapies have been shown to overcome insulin resistance, overweight and hypoglycemia are still observed in most cases. The disadvantages of insulin therapies have driven the interest in developing novel curative agents with enhanced insulin resistance reversibility. Magnesium deficiency has also been recognized as a common problem which leads to insulin resistance in both type 1 and 2 diabetes. Oxide nanoparticles demonstrate highly tunable physicochemical properties that can be exploited by engineers to develop unique oxide nanoparticles for tailored applications. Magnesium supplements for diabetic cells have been reported to increase the insulin resistance reversibility. Hence, it is hypothesized that magnesium oxide (MgO) nanoparticles could be molecularly engineered to offer enhanced therapeutic efficacy in reversing insulin resistance. In the present work, morphologically different MgO nanoparticles were synthesized and evaluated for biophysical characteristics, biocompatibility, cytotoxicity, and insulin resistance reversibility. MTT assay revealed that hexagonally shaped MgO nanoparticles are less toxic to 3T3-L1 adipose cells (diabetic) compared with spherically and rod-shaped MgO nanoparticles. MTT assays using VERO cells (normal, non-diabetic) showed that 400 µg/ml of hexagonal MgO nanoparticles were less toxic to both diabetic and non-diabetic cells. DNS glucose assay and western blot showed that hexagonally shaped MgO nanoparticles had reversed 29.5% of insulin resistance whilst fluorescence microscopy studies indicated that the insulin resistance reversal is due to the activation of intracellular enzymes. The probable mechanism for MgO nanoparticles to induce cytotoxic effect and insulin resistance reversal is discussed.


Asunto(s)
Adipocitos/efectos de los fármacos , Resistencia a la Insulina , Óxido de Magnesio/química , Nanopartículas del Metal , Células 3T3-L1 , Adipocitos/metabolismo , Animales , Calorimetría , Chlorocebus aethiops , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Transportador de Glucosa de Tipo 4/metabolismo , Concentración de Iones de Hidrógeno , Hipoglucemiantes/farmacología , Concentración 50 Inhibidora , Ratones , Microscopía Electrónica de Transmisión , Microscopía Fluorescente , Células Vero
17.
Luminescence ; 35(3): 418-426, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31846203

RESUMEN

In this paper, the Eu3+ -Eu2+ (4%, molar ratio)-doped xAl2 O3 -ySiO2 (x = 0-2.5, y = 1-5) and xAl2 O3 -zMgO (x = 0-1.5, z = 0-3) composites phosphors with different Al2 O3 to SiO2 (A/S) and Al2 O3 to MgO (A/M) ratios were prepared using a high-temperature solid-state reaction under air atmosphere. The effects of the A/S and A/M on luminescence properties, crystal structure, electron spin resonance, and Commission Internationale de l'Eclairage chromaticity coordinates of the samples were systematically analyzed. These results indicated that the different A/S and A/M ratios in the matrix effectively affected the crystal phase, degrees of self-reduction of Eu3+ , and led the relative emission intensity of Eu2+ /Eu3+ to change and adjust.


Asunto(s)
Óxido de Aluminio/química , Europio/química , Sustancias Luminiscentes/química , Óxido de Magnesio/química , Dióxido de Silicio/química , Mediciones Luminiscentes
18.
Int J Biol Macromol ; 152: 1174-1185, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31760003

RESUMEN

Interaction of metal nanoparticles and metal nanocomposites with blood proteins is important from the perspectives of cytotoxicity and production of novel drug delivery systems. In this study, Ag-MgO nanocomposites were bio-modified by different concentrations of Artemisia haussknechtii medicinal plant and Protoparmeliopsis muralis medicinal lichen extracts. Determination of physicochemical properties of NCs were carried out by UV-Visible spectroscopy, scanning electron microscope (SEM), X-ray powder diffraction (XRD), and Fourier transform infrared (FT-IR) analyses. Antibacterial effects of NCs against methicillin-resistant Staphylococcus aureus (MRSA), E. coli ATCC 25922, and P. aeruginosa ATCC 27853 bacteria were measured by disc diffusion and minimum inhibition/bactericidal concentrations (MIC and MBC). Also, in final section, interaction of bio-modified NCs (BNCs) with hemoglobin (Hb) protein was surveyed by SEM, atomic force microscope (AFM), and FT-IR techniques. BNCs by plant extract (10%w/v) showed highest antibacterial effects on E. coli ATCC 25922 as inhibition zone diameter of (IZD) value of 20 ± 0.89 mm. Aggregation of Hb around BNCs was approved by mentioned analyses. This investigation illustrated contribution of various functional groups including thiol and imidazole groups in self-assembly of Hb surrounding BNCs.


Asunto(s)
Antibacterianos/química , Artemisia/química , Ascomicetos/química , Hemoglobinas/química , Óxido de Magnesio/química , Nanocompuestos/química , Plata/química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Quitosano/química , Cobre/química , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana/métodos , Extractos Vegetales/química , Extractos Vegetales/farmacología
19.
Mater Sci Eng C Mater Biol Appl ; 107: 110314, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31761184

RESUMEN

This review focuses on the biomedical applications and toxicity of spinel ferrite nanoparticles (SFNPs) with more emphasis on the recently published work. A critical review is provided on recent advances of SFNPs applications in biomedical areas. The novelty of SFNPs in addressing the bottleneck problems encountered in the areas of health; in particular, for diagnosis and treatment of tumour cells are well reviewed. Furthermore, research gaps, toxicity of SFNPs and areas which still need more attention are highlighted. Based on the result of this review, the SFNPs have unlimited capacity in cancer treatment, disease diagnosis, magnetic resonance imaging, drug delivery and release. Overall, stepping out of the conventional way of treatment is difficult but also essential in bringing long lasting solution for cancer and other diseases treatment. In fact, the toxicity study and commercialisation of the SFNPs based cancer treatment options are the main challenges and need further study, in order to reduce unforeseen consequences.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Hipertermia Inducida/métodos , Nanocompuestos/química , Nanocompuestos/uso terapéutico , Nanopartículas/química , Nanopartículas/uso terapéutico , Óxido de Aluminio/química , Animales , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/uso terapéutico , Compuestos Férricos/química , Humanos , Óxido de Magnesio/química , Nanocompuestos/toxicidad , Nanopartículas/toxicidad , Neoplasias/diagnóstico
20.
J Pharm Biomed Anal ; 179: 112957, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31735474

RESUMEN

Microwave-assisted activated carbon was fabricated from lentil waste (LW) by K2CO3 chemical activation at optimum production conditions and the synthesized optimal activated carbon (LWAC) with a high surface area (1875 m2/g) was used as a matrix for spinel ferrite composite production. CuFe2O4 nanoparticles were embedded to LWAC and a novel magnetic composite material (M-LWAC) was synthesized. A detailed structural and textural analysis of M-LWAC was made by using various characterization techniques. M-LWAC was also used as an effectual remover for tetracycline (TC) bearing wastewater with 384.62 mg/g of adsorption capacity. Kinetic, isotherm and thermodynamic analyses indicated the fast, effective and spontaneous adsorption of TC by M-LWAC.


Asunto(s)
Óxido de Aluminio/química , Compuestos Férricos/química , Óxido de Magnesio/química , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Adsorción , Antibacterianos/química , Materiales Biocompatibles/química , Carbón Orgánico/química , Fenómenos Magnéticos , Nanocompuestos , Tetraciclina/química , Termodinámica , Purificación del Agua/métodos
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