Adsorption of Cr(VI) on nano Uio-66-NH2 MOFs in water

• Published in: Environmental technology Vol. 39; no. 15; pp. 1937 - 1948
• Main Authors: Wu, Shibiao, Ge, Yejun, Wang, Yaqin, Chen, Xia, Li, Feifei, Xuan, Han, Li, Xi
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03-08-2018; Taylor & Francis Ltd
• Subjects: Adsorbents; Adsorption; Aqueous solutions; Chromium; Cr(VI); Kinetics; Membranes; Metal-organic frameworks; Reaction kinetics; Temperature dependence; thermodynamics; Uio-66-NH
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2017.1344732

An efficient adsorbent, nano Uio-66-NH
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Metal-organic frameworks (MOFs), for the high efficiency removal of Cr(VI) from aqueous solution was successfully synthesized. The adsorbent was characterized and its performance in Cr(VI) removal was evaluated for the first time. Kinetic data reveal that the Cr(VI) adsorption is rapid in the beginning followed by a slower adsorption process; The Cr(VI) adsorption kinetics were well described by the pseudo-second-order kinetics model. The calculated adsorption capacity of this adsorbent for Cr(VI) by Langmuir model was 32.36 mg/g at pH 6.5. The temperature-dependent isotherms indicated that the adsorption reaction of Cr(VI) on the MOFs was a spontaneous process. Filtration experiments revealed that the membranes fabricated by the MOFs could quickly remove Cr(VI) ions from the aqueous solutions. Electrostatic attraction between Uio-66-NH
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and Cr(VI) should be the mechanism for Cr(VI) adsorption by Uio-66-NH
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.