Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal
The fabrication of chitosan (CH) biocomposite beads with variable copper (Cu<sup>2+</sup>) ion doping was achieved with a glutaraldehyde cross-linker (CL) through three distinct methods: (1) formation of CH beads was followed by imbibition of Cu(II) ions (CH-<i>b</i>-Cu) with...
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MDPI AG
2024-01-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/29/2/445 |
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| author | Inimfon A. Udoetok Abdalla H. Karoyo Mohamed H. Mohamed Lee D. Wilson |
| author_facet | Inimfon A. Udoetok Abdalla H. Karoyo Mohamed H. Mohamed Lee D. Wilson |
| author_sort | Inimfon A. Udoetok |
| collection | DOAJ |
| description | The fabrication of chitosan (CH) biocomposite beads with variable copper (Cu<sup>2+</sup>) ion doping was achieved with a glutaraldehyde cross-linker (CL) through three distinct methods: (1) formation of CH beads was followed by imbibition of Cu(II) ions (CH-<i>b</i>-Cu) without CL; (2) cross-linking of the CH beads, followed by imbibition of Cu(II) ions (CH-<i>b</i>-CL-Cu); and (3) cross-linking of pristine CH, followed by bead formation with Cu(II) imbibing onto the beads (CH-CL-<i>b</i>-Cu). The biocomposites (CH-<i>b</i>-Cu, CH-<i>b</i>-CL-Cu, and CH-CL-<i>b</i>-Cu) were characterized via spectroscopy (FTIR, <sup>13</sup>C solid NMR, XPS), SEM, TGA, equilibrium solvent swelling methods, and phosphate adsorption isotherms. The results reveal variable cross-linking and Cu(II) doping of the CH beads, in accordance with the step-wise design strategy. CH-CL-<i>b</i>-Cu exhibited the greatest pillaring of chitosan fibrils with greater cross-linking, along with low Cu(II) loading, reduced solvent swelling, and attenuated uptake of phosphate dianions. Equilibrium and kinetic uptake results at pH 8.5 and 295 K reveal that the non-CL Cu-imbibed beads (CH-<i>b</i>-Cu) display the highest affinity for phosphate (Q<i><sub>m</sub></i> = 133 ± 45 mg/g), in agreement with the highest loading of Cu(II) and enhanced water swelling. Regeneration studies demonstrated the sustainability and cost-effectiveness of Cu-imbibed chitosan beads for controlled phosphate removal, whilst maintaining over 80% regenerability across several adsorption–desorption cycles. This study offers a facile synthetic approach for controlled Cu<sup>2+</sup> ion doping onto chitosan-based beads, enabling tailored phosphate oxyanion uptake from aqueous media by employing a sustainable polysaccharide biocomposite adsorbent for water remediation by mitigation of eutrophication. |
| first_indexed | 2024-03-08T09:49:28Z |
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| id | doaj.art-2eab1f12a26f4c9cb3bc0f399a4b7858 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-08T09:49:28Z |
| publishDate | 2024-01-01 |
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| series | Molecules |
| spelling | doaj.art-2eab1f12a26f4c9cb3bc0f399a4b78582024-01-29T14:08:42ZengMDPI AGMolecules1420-30492024-01-0129244510.3390/molecules29020445Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate RemovalInimfon A. Udoetok0Abdalla H. Karoyo1Mohamed H. Mohamed2Lee D. Wilson3Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, CanadaDepartment of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, CanadaDepartment of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, CanadaDepartment of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, CanadaThe fabrication of chitosan (CH) biocomposite beads with variable copper (Cu<sup>2+</sup>) ion doping was achieved with a glutaraldehyde cross-linker (CL) through three distinct methods: (1) formation of CH beads was followed by imbibition of Cu(II) ions (CH-<i>b</i>-Cu) without CL; (2) cross-linking of the CH beads, followed by imbibition of Cu(II) ions (CH-<i>b</i>-CL-Cu); and (3) cross-linking of pristine CH, followed by bead formation with Cu(II) imbibing onto the beads (CH-CL-<i>b</i>-Cu). The biocomposites (CH-<i>b</i>-Cu, CH-<i>b</i>-CL-Cu, and CH-CL-<i>b</i>-Cu) were characterized via spectroscopy (FTIR, <sup>13</sup>C solid NMR, XPS), SEM, TGA, equilibrium solvent swelling methods, and phosphate adsorption isotherms. The results reveal variable cross-linking and Cu(II) doping of the CH beads, in accordance with the step-wise design strategy. CH-CL-<i>b</i>-Cu exhibited the greatest pillaring of chitosan fibrils with greater cross-linking, along with low Cu(II) loading, reduced solvent swelling, and attenuated uptake of phosphate dianions. Equilibrium and kinetic uptake results at pH 8.5 and 295 K reveal that the non-CL Cu-imbibed beads (CH-<i>b</i>-Cu) display the highest affinity for phosphate (Q<i><sub>m</sub></i> = 133 ± 45 mg/g), in agreement with the highest loading of Cu(II) and enhanced water swelling. Regeneration studies demonstrated the sustainability and cost-effectiveness of Cu-imbibed chitosan beads for controlled phosphate removal, whilst maintaining over 80% regenerability across several adsorption–desorption cycles. This study offers a facile synthetic approach for controlled Cu<sup>2+</sup> ion doping onto chitosan-based beads, enabling tailored phosphate oxyanion uptake from aqueous media by employing a sustainable polysaccharide biocomposite adsorbent for water remediation by mitigation of eutrophication.https://www.mdpi.com/1420-3049/29/2/445chitosan beadsbiocomposite adsorbentglutaraldehyde cross-linkingCu(II) ion complexationphosphate |
| spellingShingle | Inimfon A. Udoetok Abdalla H. Karoyo Mohamed H. Mohamed Lee D. Wilson Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal Molecules chitosan beads biocomposite adsorbent glutaraldehyde cross-linking Cu(II) ion complexation phosphate |
| title | Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal |
| title_full | Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal |
| title_fullStr | Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal |
| title_full_unstemmed | Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal |
| title_short | Chitosan Biocomposites with Variable Cross-Linking and Copper-Doping for Enhanced Phosphate Removal |
| title_sort | chitosan biocomposites with variable cross linking and copper doping for enhanced phosphate removal |
| topic | chitosan beads biocomposite adsorbent glutaraldehyde cross-linking Cu(II) ion complexation phosphate |
| url | https://www.mdpi.com/1420-3049/29/2/445 |
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