Comparison on the performance of green and conventional magnetic chitosan-based composites in the removal of complex dyes: Synergetic effect, experimental and theoretical studies

Author(s)

Camparotto, Natalia Gabriele ; Fulaneti, Gabriel Henrique Silva ; Fokoue, Harold Hilarion ; Mastelaro, Valmor Roberto ; Vieira, Melissa Gurgel Adeodato ; Prediger, Patricia

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 289, p. 20-pg., 2024-12-20.

Abstract

The presence of complex dyes, which possess four or more aromatic rings, is pervasive in environmental matrices. Nanomaterials offer a promising avenue for their removal. In this study, we synthesized novel magnetic nanocomposites comprising nanochitosan (nCS) and iron nanoparticles through the application of green and conventional protocols. In the preparation of the green composite, designated as G-nCS@FeNPs, eucalyptus leaves extract and proanthocyanidins were employed as reducing and crosslinking agents, respectively. In contrast, the conventional composite, designated as C-nCS@FeNPs, utilized ammonia and glutaraldehyde as the reducing and crosslinking agents, respectively. The G-nCS@FeNPs exhibited a more electropositive surface, and prominent magnetic properties. The zeta potential measurements of the G-nCS@FeNPs (ranging from +36 to +30 mV) were more positive than those of the C-nCS@FeNPs (+35 to-2.79 mV). Additionally, the C content in C-nCS@FeNPs was less (36.4 %) than in G-nCS@FeNPs (57.2 %), which is likely due to the higher nanochitosan content and the presence of proanthocyanidins in the green nanocomposite. The G-nCS@FeNPs exhibited a tridimensional porous structure, whereas the conventional composite appeared to form a CS film with an uneven surface and embedded FeNPs. G-nCS@FeNPs demonstrated remarkable potential as an adsorbent material for the removal of anionic reactive dyes, namely orange 122 (RO122) and red 250 (RR250). It exhibited an exceptional adsorption capacity of 3005 mg.g- 1 for RO122. A DFT study revealed that the RO122 molecule displays enhanced reactivity towards the adsorbent surface. Moreover, experiments conducted in saline media and XPS and FTIR analyses post-adsorption indicated that 78.8 % of the interactions between RO122 and the adsorbent are based on electrostatic and ion exchange, while the remaining 22.2 % are attributed to pi- pi and hydrogen bonds. Also, G-nCS@FeNPs demonstrated a synergistic effect on the removal of the cationic dye safranin in multicomponent systems, exhibiting an increase in removal capacity from 0 to 169 mg.g-1. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 22/14834-0 - Synthesis of new nanoadsorbents, their characterizations and applications in pollutant adsorption in water
• Grantee: Patricia Prediger
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/02041-8 - Preparation of MOF-based polymeric membranes containing niobium by rotary jet-spun and its application in the removal of contaminants in water
• Grantee: Natália Gabriele Camparotto
• Support Opportunities: Scholarships in Brazil - Doctorate