Open Access

ARTICLE

Iron Modified Opuntia ficus-indica Cladode Powder as a Novel Adsorbent for Dyes Molecules

Mehrzia Krimi^1,*, Nabil Nasri¹, Alma Jandoubi¹, Sami Boufi², Rached Ben Hassen¹

1 Laboratory of Materials and Environment for Sustainable Development, LR18ES10, University of Tunis El Manar, 9, Avenue Dr. Zoheir Safi, Tunis, 1006, Tunisia
2 Faculty of Science, University of Sfax, LMSE BP 802-3018, Sfax, 3000, Tunisia

* Corresponding Author: Mehrzia Krimi. Email:

(This article belongs to the Special Issue: Biobased Materials for Advanced Applications )

Journal of Renewable Materials 2025, 13(8), 1623-1644. https://doi.org/10.32604/jrm.2025.02025-0023

Received 08 February 2025; Accepted 07 April 2025; Issue published 22 August 2025

Abstract

In this study, Opuntia ficus-indica cladode powder (OFIC), locally sourced from Rabta in Tunis, was utilized as a novel, eco-friendly adsorbent in both raw and iron(III) chloride-modified forms. The presence of iron in the modified material was confirmed by X-ray fluorescence spectroscopy (XRF). The neat and modified biomass were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), and their usefulness as adsorbent for cationic Neutral Red (NR) and anionic Congo Red (CR) dyes were explored under batch conditions. Equilibrium studies revealed that the iron-modified Fe(OH)_x@Cellulose adsorbent exhibited superior adsorption capabilities for both dyes compared to the raw material. Moreover, CR dye was more effectively adsorbed by Fe(OH)_x@Cellulose than NR. The adsorption isotherms for both dyes were fitted. The results demonstrated that the adsorption of both NR and CR dyes onto the biosorbent Fe(OH)_x@Cellulose was closely followed by the Langmuir model, with R² values of 0.980 and 0.973 for NR and CR, respectively, and the pseudo-second-order kinetic model better depicted the adsorption kinetic. Thermodynamic analysis revealed a negative enthalpy value (−67.15 kJ/mol) for NR adsorption, suggesting an exothermic process, while a positive enthalpy value (3.99 kJ/mol) was observed for CR adsorption, indicating an endothermic process.

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