Hydroxyapatite modified ZIF-67 composite with abundant binding groups for the highly efficient and selective elimination of uranium (VI) from wastewater.
J Hazard Mater
; 426: 127834, 2022 03 15.
Article
em En
| MEDLINE
| ID: mdl-34865903
ABSTRACT
In this work, nanoscale hydroxyapatite (HAP)-modified ZIF-67 composite, HAP/ZIF-67, with abundant functional groups for uranium(VI) binding was synthesized via a facile ultrasound-assisted synthesis method. The prepared HAP/ZIF-67 was characterized by XRD, SEM, TEM, BET, FT-IR and XPS techniques, and was applied to eliminate uranium(VI) from aqueous solutions under various conditions, i.e., pH, coexisting ions, temperature and contact time. The results indicate that the abundant Co-OH, -CN- and -NH- binding groups originating from the ZIF-67 and the Ca-OH and PO43- derived from loaded nanoscale HAP synergistically endowed HAP/ZIF-67 with the excellent U(VI) adsorption capacity of 453.1 mg/g, which is 2.55 and 1.78 times that of pristine HAP and ZIF-67. HAP/ZIF-67 showed high adsorption selectivity toward U(VI), and the U(VI) elimination efficiency for real wastewater by HAP/ZIF-67 reached 97.29%. The adsorption kinetics and isotherms were well simulated by the pseudo-second-order model and Langmuir isotherm model, respectively, suggesting that U(VI) adsorption was an endothermic monolayer chemisorption process. The adsorption mechanism of U (VI) by HAP/ZIF-67 was dominated by surface complexation process. This work is expected to provide an effective strategy for developing HAP-modified MOFs absorbent to be used for the highly efficient elimination of radionuclides from wastewater.
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MEDLINE
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Urânio
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En
Ano de publicação:
2022
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Article