A1 Journal article (refereed), original research

Polyethylenimine-modified chitosan materials for the recovery of La(III) from leachates of bauxite residue


Open Access publication

Publication Details
Authors: Zhao Feiping, Yang Ziqi, Wei Zongsu, Spinney Richard, Sillanpää Mika, Tang Juntao, Tam Michael, Xiao Ruiyang
Publisher: Elsevier
Publication year: 2020
Language: English
Related Journal or Series Information: Chemical Engineering Journal
Journal acronym: Chem Eng J
Volume number: 388
ISSN: 1385-8947
eISSN: 1873-3212
JUFO-Level of this publication: 3
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe202002216140

Abstract

The separation and recovery of rare earth elements (REEs) from leachates of bauxite residue has attracted increasing attention. Yet, the characteristics of bauxite residue leachates (low pH, low concentration of REEs, and co-existence of other trivalent ions) results in a longstanding challenge in the recovery of REEs. Here, we reported on the development of polyethylenimine (PEI) modified chitosan materials as efficient adsorbents for REE, La(III). The introduction of PEI brought abundant protonatable amino nitrogen atoms, which endows materials with excellent buffering capacity at extremely acidic pH. The PEI-chitosan materials can easily separate La(III) from Al(III), a major co-existing ion, with a separation factor of 3.1. The single-metal adsorption behavior showed fast and efficient adsorption capacity of 2.015 mmol/g for La(III). In binary systems, La(III) was preferentially adsorbed over Al(III) due to the higher degree of association with PEI. The FT-IR, XPS and EDS mapping results revealed that in the binding mechanism the N atoms form coordination bonds with La(III) by sharing an electron pair, resulting in eight-membered chelate rings. The PEI-chitosan materials also exhibited an excellent reusability with regeneration efficiency of 90% after 4 recycles. Overall, PEI-chitosan demonstrates that it is a viable and economical material for the separation and preconcentration of REEs from leachates of bauxite residue.


Last updated on 2020-21-02 at 11:34