Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Int J Biol Macromol ; 229: 344-353, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36586656

RESUMO

A sustainable and efficient nanobentonite@sodium alginate@oleylamine (Nbent@Alg@OA) nanocomposite has been successfully synthesized via coating reaction of nanobentonite (Nbent) with alginate (Alg) and oleylamine (OA). The nanocomposite has been characterized and examined for the adsorption of 60Co(II) and 152+154Eu(III) radionuclides from simulated radioactive waste solution. FT-IR, XRD, SEM, and HR-TEM techniques have been applied to confirm the structural and morphological characteristics of the Nbent@Alg@OA nanocomposite. The effects of various parameters, such as pH of the medium, initial concentration of the radionuclides, contact time, and temperature on the adsorption of 60Co(II) and 152+154Eu(III) radionuclides were investigated by the batch adsorption technique. The results revealed that the optimum pH values for the adsorption of 152+154Eu (III) and 60Co (II) radionuclides were 4 and 5, respectively. The adsorption capacity of 152+154Eu(III) (65.6219 mg/g) was found greater than that of 60Co(II) (47.3469 mg/g). The adsorption process was found to be well described by the pseudo-second-order kinetic model. Furthermore, the equilibrium isotherm evaluation revealed that the Langmuir model was adequately matched with the adsorption data. According to the thermodynamic characteristics, the adsorption process was endothermic and spontaneous. Regeneration and reuse of Nbent@Alg@OA nanocomposite confirmed that the recycled nanocomposite was sufficiently efficient in several successive practical applications.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Espectroscopia de Infravermelho com Transformada de Fourier , Adsorção , Alginatos/química , Radioisótopos de Cobalto , Nanocompostos/química , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio , Cinética
2.
Appl Radiat Isot ; 188: 110324, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35793582

RESUMO

A Promising nanocomposite from ß-Cyclodextrin/Alginate (ß-CD/Alg) composite impregnated with nickel oxide nanoparticles (NiO) has been synthesized and characterized using diverse techniques like FT-IR, XRD, TGA, and SEM. The new nanocomposite has been investigated for the efficient remediation of 51Cr and 56Mn radionuclides from simulated contaminated radioactive water. All the controlling experimental parameters such as solution pH, contact time, initial radionuclides concentration and adsorbent mass have been investigated and optimized. The distribution coefficient values Kd (mL/g) for 51Cr and/or 56Mn radionuclides have been calculated for all factors it was found that the optimum pH values were at 5 and 6 with Kd 5300, and 4500, for 51Cr and/or 56Mn, respectively and the equilibrium was at 90 and 100 (min) with Kd values 5600 and 4800 for 51Cr and/or 56Mn, respectively.


Assuntos
Recuperação e Remediação Ambiental , Poluentes Radioativos , beta-Ciclodextrinas , Adsorção , Alginatos , Concentração de Íons de Hidrogênio , Cinética , Níquel , Radioisótopos , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , beta-Ciclodextrinas/química
3.
Appl Radiat Isot ; 159: 108989, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32250753

RESUMO

The contribution of oleyl amine as a biodegradable and simple aliphatic compound containing amine functional group (-NH2) was discussed in this work with respect to the remediation process of heavy metal ions from aqueous solution. Manganese oxide nanoparticles were synthesized via combustion synthesis and then functionalized with oleyl amine to form a new nanosorbent (NMn3O4-OA).The characteristics of this nanosorbent were examined using different instruments, such as Fourier-transform infrared spectroscopy, thermal gravimetric analysis, X-ray powder diffraction and high-resolution transmission electron microscopy. The HR-TEM images confirmed nanoscale range for NMn3O4-OA between 41.30 and 61.86 nm. The influence of diverse parameters on remediation of ZnII/CoII was examined, involving pH of metal ion solutions (pH 1-7), reaction time (1-60 min), solid amount (5-100 mg) and ionic concentration (0.1-2.0 mol/L). The optimum conditions were found pH 7 and 5-20 min reaction time for the two metal ions. The maximum capacities for adsorptive remediation were found 202 and 100 mgg-1for ZnII and Co II, respectively.

4.
Environ Sci Pollut Res Int ; 25(22): 22120-22135, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29802617

RESUMO

A comparative study between two nanosorbents, nanopolyaniline (NPANI) and nanopolyaniline coated with nanosilver oxide (NPANI-NAg2O) is explored to dispose the divalent species of Zn/Co from water and radioactive isotopes 65Zn/60Co from radioactive wastewater using batch and column techniques. NPANI-NAg2O nanocomposite was synthesized via solid-solid reaction. Characterization was achieved using FT-IR, TGA, XRD, SEM, HR-TEM, and surface area analysis. The images of SEM and HR-TEM confirmed the success of the modification process and the particle size was found in the range 28.78-68.28 nm (NPANI) and 25.74-85.71 nm (NPANI-NAg2O), respectively. Solution pH, contact time, solid dosage, and ionic concentration of the metals were studied as fundamental factors. The obtained results indicated that the optimum conditions to dispose Zn/Co divalent species using NPANI were pH 7 and 30-33 min, while NPANI-NAg2O exhibited the optimum conditions at pH 7 and 20-30 min. The maximum removal capacities were 100.1 and 139.75 mg/g for Zn(II) and 57.93 and 112.1 mg/g for Co(II) using NPANI and NPANI-NAg2O, respectively. Graphical abstract ᅟ.


Assuntos
Compostos de Anilina/síntese química , Radioisótopos de Cobalto/química , Nanocompostos/química , Óxidos/química , Compostos de Prata/química , Poluentes Radioativos da Água/isolamento & purificação , Radioisótopos de Zinco/química , Adsorção , Química Verde , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias/química , Purificação da Água/métodos , Zinco
5.
Ecotoxicol Environ Saf ; 145: 665-673, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28843201

RESUMO

A novel material was designed using layer-by-layer functionalization of nanobentonite with nanopolyaniline and oleic acid to produce an efficient NBent-NPA-OA nanosorbent to adsorb the divalent ionic Zn/Co and their radioisotopes 65Zn/60Co from tap water and radioactive wastewater. The new nanosorbent was characterized by Fourier-transform-infrared (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and determination of surface area. The NBent-NPA-OA particle size was ranged between 9.45 and 33.60nm according to HR-TEM analysis. The FT-IR exhibited several characteristic absorption peaks due to the existence of deposited layers of nanopolyaniline and oleic acid on the surface of nanobentonite surface. Different experimental parameters including, initial pH, contact time, nanosorbent, initial concentration of the target metals and interfering ions were varied, investigated and optimized to evaluate the removal efficiency of the divalent ionic Zn/Co from their solutions by the action of NBent-NPA-OA nanosorbent. The collected batch equilibrium results confirmed the efficiency of newly functionalized NBent-NPA-OA nanosorbent to uptake the divalent ionic Zn/Co from their solutions (10.0mL of 0.01mol/L) with maximum capacity values 2.916 and 1.960mmolg-1, respectively using 5.0mg nanosorbent, pH 6.0 and 20min contact reaction time. The multistage microcolumn system was successfully implemented to remove the divalent ionic Zn/Co from tap water in addition to their radioisotopes 65Zn/60Co from radioactive wastewater. The current study refers to an excellent recovery and the removal percent of the radioisotopes 65Zn (96.4) and 60Co (92.7%) using NBent-NPA-OA nanosorbent.


Assuntos
Compostos de Anilina/química , Bentonita/química , Nanopartículas/química , Ácido Oleico/química , Águas Residuárias/química , Poluentes Radioativos da Água/análise , Purificação da Água/métodos , Adsorção , Cátions Bivalentes/análise , Cobalto/análise , Radioisótopos de Cobalto , Poluentes Químicos da Água/análise , Zinco/análise , Radioisótopos de Zinco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA