Construction of efficient Ni-FeLDH@MWCNT@Cellulose acetate floatable microbeads for Cr(VI) removal: Performance and mechanism

Ahmed M Omer; Gehad S Elgarhy; Gehan M El-Subruiti; Eman M Abd El-Monaem; Abdelazeem S Eltaweil

doi:10.1016/j.carbpol.2023.120771

Construction of efficient Ni-FeLDH@MWCNT@Cellulose acetate floatable microbeads for Cr(VI) removal: Performance and mechanism

Carbohydr Polym. 2023 Jul 1:311:120771. doi: 10.1016/j.carbpol.2023.120771. Epub 2023 Mar 3.

Authors

Ahmed M Omer¹, Gehad S Elgarhy², Gehan M El-Subruiti², Eman M Abd El-Monaem², Abdelazeem S Eltaweil³

Affiliations

¹ Polymer Materials Research Department, Advanced Technology and New Materials Research Institute (ATNMRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, P. O. Box: 21934, Alexandria, Egypt. Electronic address: Ahmedomer_81@yahoo.com.
² Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
³ Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt. Electronic address: abdelazeemeltaweil@alexu.edu.eg.

PMID: 37028881
DOI: 10.1016/j.carbpol.2023.120771

Abstract

Water pollution is an aggravating dilemma that is extending around the world, threatening human survival. Strikingly, the notorious heavy metals like hexavalent chromium ions (Cr⁶⁺) cause environmental problems raising awareness of the essentials for finding feasible solutions. For this purpose, the self-floating Ni-FeLDH@MWCNT@CA microbeads were prepared for removing Cr⁶⁺. The morphological, thermal, and composition characteristics of Ni-FeLDH@MWCNT@CA microbeads were analyzed using XRD, FTIR, TGA, SEM, XPS, and zeta potential. Notably, the adsorption aptitude of Cr⁶⁺ was enhanced by raising the MWCNTs proportion to 5 wt% in microbeads. The Cr⁶⁺ adsorption onto Ni-FeLDH@MWCNT@CA fitted Langmuir and Freundlich isotherm models with q_m of 384.62 mg/g at pH 3 and 298 K. The adsorption process was described kinetically by the pseudo-2nd order model. More importantly, the adsorption of Cr⁶⁺ onto Ni-FeLDH@MWCNT@CA occurred via electrostatic interactions, inner/outer sphere complexations, ion exchange, and reduction mechanisms. Besides, the cycling test showed the remarkable reusability of Ni-FeLDH@MWCNT@CA floatable microbeads for five subsequent cycles. The self-floating Ni-FeLDH@MWCNT@CA microbeads in this work provide essential support for the potential applications for the remediation of heavy metals-containing wastewater.

Keywords: CA, MWCNTs; Cr(6+) adsorption; Floating; LDH; Mechanism.