Effective adsorption of mercury by Zr(IV)-based metal-organic frameworks of UiO-66-NH2 from aqueous solution.
Environ Sci Pollut Res Int
; 28(6): 7068-7075, 2021 Feb.
Article
em En
| MEDLINE
| ID: mdl-33025445
ABSTRACT
In this study, Zr-based metal-organic frameworks (MOFs) of UiO-66 and UiO-66-NH2 were synthesized and applied to removal of mercury from aqueous solution. The characterizations of UiO-66 and UiO-66-NH2 were examined by X-ray diffraction (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). To investigate the adsorption properties of UiO-66-NH2 for mercury, the experiments of kinetics, isotherm, pH, temperature, and salt concentration were conducted, and the results were compared with those by UiO-66. The result showed that UiO-66-NH2 has a higher adsorption capacity for mercury than UiO-66. The maximum adsorption capacity of UiO-66-NH2 was 223.8 ± 17.8 mg g-1 at 313 K. The salt concentration of NaCl has a significant effect on the adsorption of mercury on UiO-66, while UiO-66-NH2 can maintain the stable adsorption capacity for mercury in the concentration range of 0.1-0.5 M NaCl. Adsorption thermodynamics result indicated that the adsorption process of mercury on UiO-66-NH2 was spontaneous and endothermic. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses showed that the mercury was successfully adsorbed on the surface of UiO-66-NH2 and amino functional group as a soft base played a major role to react with mercury during the adsorption process. Graphical abstract.
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MEDLINE
Assunto principal:
Purificação da Água
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Estruturas Metalorgânicas
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Mercúrio
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article