Cost-effective zinc ferrite-functionalized hydroxyethyl cellulose/chitosan film for efficient removal of methyl orange dye from aqueous solutions

Abstract

The increasing contamination of water bodies with toxic dyes, particularly methyl orange (MO), has become a significant environmental challenge. In this study, we present an adsorbent, zinc ferrite-loaded hydroxyethyl cellulose/chitosan film (ZnFe₂O₄@HEC/Cs), designed for the efficient removal of MO dye from aqueous solutions. These composites combine the magnetic properties of ZnFe₂O₄ with the biocompatibility of HEC and Cs, forming a robust material with excellent MO dye adsorption capabilities. For comparison, three different concentrations of ZnFe₂O₄ (0.1, 0.2, and 0.3 g) were added to the HEC/Cs solution prior to the film preparations. These prepared films that loaded with the different concentrations of ZnFe₂O₄ were nominated as 1ZnFe₂O₄@HEC/Cs, 2ZnFe₂O₄@HEC/Cs, and 3ZnFe₂O₄@HEC/Cs films and compared with the films (HEC/Cs) that prepared without ZnFe₂O₄ loading. The prepared films (1ZnFe₂O₄@HEC/Cs, 2ZnFe₂O₄@HEC/Cs, and 3ZnFe₂O₄@HEC/Cs) exhibited rough morphological surface. The influence of various parameters such as pH, dye concentration, adsorbent dose, and contact time were systematically explored to optimize the adsorption conditions. Compared to pure HEC/Cs (199 mg/g), the adsorption power of MO dye sequestration in the presence of 3ZnFe₂O₄@HEC/Cs was 288 mg/g. The experimental results are described by chemical kinetics with a pseudo-second order. The Freundlich and Langmuir adsorption models were employed to analyze the experimental results indicating multilayer adsorption of MO dye. The results reveal that the ZnFe₂O₄@HEC/Cs composite demonstrates a rapid adsorption rate and high dye removal efficiency, with the ability to maintain its performance even in the presence of common contaminants. Moreover, the composite can be easily regenerated, offering a sustainable solution for dye removal in wastewater treatment. This study provides valuable insights into designing advanced, environmentally friendly adsorbents to remove dyes from polluted water. The exceptional performance and reusability of ZnFe₂O₄@HEC/Cs films highlight their potential for large-scale wastewater treatment applications.

Keywords: Adsorption; Composite film; Hydroxyethyl cellulose; Wastewater treatment; Zinc ferrite.