3D Composite U(VI) Adsorbents Based on Alginate Hydrogels and Oxidized Biochar Obtained from <i>Luffa cylindrica</i>

3D naturally derived composites consisting of calcium alginate hydrogels (CA) and oxidized biochar obtained from <i>Luffa cylindrica</i> (ox-LC) were synthesized and further evaluated as adsorbents for the removal of U(VI) from aqueous media. Batch-type experiments were conducted to inve...

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Bibliographic Details
Main Authors: Andreas Ayiotis, Efthalia Georgiou, Panagiotis S. Ioannou, Ioannis Pashalidis, Theodora Krasia-Christoforou
Format: Article
Language:English
Published: MDPI AG 2023-10-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/16/19/6577
Description
Summary:3D naturally derived composites consisting of calcium alginate hydrogels (CA) and oxidized biochar obtained from <i>Luffa cylindrica</i> (ox-LC) were synthesized and further evaluated as adsorbents for the removal of U(VI) from aqueous media. Batch-type experiments were conducted to investigate the effect of various physicochemical parameters on the adsorption performance of materials. The maximum adsorption capacity (q<sub>max</sub>) was 1.7 mol kg<sup>−1</sup> (404.6 mg·g<sup>−1</sup>) at pH 3.0 for the CA/ox-LC with a 10% wt. ox-LC content. FTIR spectroscopy indicated the formation of inner-sphere complexes between U(VI) and the surface-active moieties existing on both CA and ox-LC, while thermodynamic data revealed that the adsorption process was endothermic and entropy-driven. The experimental data obtained from the adsorption experiments were well-fitted by the Langmuir and Freundlich models. Overall, the produced composites exhibited enhanced adsorption efficiency against U(VI), demonstrating their potential use as effective adsorbents for the recovery of uranium ions from industrial effluents and seawater.
ISSN:1996-1944