Issue 64, 2017, Issue in Progress

Preparation of PEI/CS aerogel beads with a high density of reactive sites for efficient Cr(vi) sorption: batch and column studies

Abstract

In view of the sustainable character and high-density of reactive sorption sites, a new kind of poly(ethylenimine)/chitosan (PEI/CS) aerogel beads were successfully synthesized using controllable sol–gel and freeze drying methods, with the aim of using them for efficient Cr(VI) removal from aqueous acid solutions. Compared with the reported CS-based sorbents for hexavalent chromium [Cr(VI)], not only is the synthetic process used simple but the bead-like samples could be easily separated from solutions for recycling. Structural characterization and batch experiments were compared to illustrate the adsorption performance of the aerogel beads which were synthesized using various processes. Out of the three samples (CS–glutaraldehyde (GA), CS–GA–PEI and CS/PEI–GA beads), the one referred to as CS–GA–PEI exhibited the highest adsorption capacity and the maximum amount of Cr(VI) removal was 402.9 mg g−1 at pH 2.0 and 298 K. The pseudo-second-order and Langmuir model preferably fitted the adsorption process best. After five cycles of desorption–regeneration tests, more than 80% of Cr(VI) could still be removed by these newly designed CS–GA–PEI beads. Adsorption mechanisms could be explained using electrostatic attraction and reduction reaction theories, on the basis of comprehensive analysis. More importantly, taking advantage of the micrometer sized particles and three-dimensional network that developed, fixed-bed column tests were also conducted on the resultant bead-like sample, which also exhibited excellent sorption performance under testing conditions. These superiorities of CS–GA–PEI beads make them a potential candidate for use in remediating the pollution caused by Cr(VI) ions.

Graphical abstract: Preparation of PEI/CS aerogel beads with a high density of reactive sites for efficient Cr(vi) sorption: batch and column studies

Supplementary files

Article information

Article type
Paper
Submitted
21 Jun 2017
Accepted
04 Aug 2017
First published
16 Aug 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 40227-40236

Preparation of PEI/CS aerogel beads with a high density of reactive sites for efficient Cr(VI) sorption: batch and column studies

R. Li, Q. An, Z. Xiao, B. Zhai, S. Zhai and Z. Shi, RSC Adv., 2017, 7, 40227 DOI: 10.1039/C7RA06914F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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