Novel waste wool fabric reinforced alginate-gum hydrogel composites for rapid and selective Pb (II) adsorption

Abstract

Heavy metals employed in various industrial applications can negatively impact both the ecosystem and human beings. Common techniques for eliminating pollutants often rely on expensive materials. So, this study focuses on exploring economical alternatives obtained from nature and textile waste. In this study, a hydrogel composite was synthesized using wool nonwoven fabric mixed with alginate, gum Arabic (GA), and xanthan gum (XG) to evaluate its efficacy in adsorbing lead (Pb) from aqueous solutions. The composites were characterized using SEM, FTIR, and XPS to understand their structure and composition before and after Pb adsorption. The effects of time, pH, and initial metal ion concentration on Pb adsorption by the composite were also investigated. Maximum adsorption was observed at a basic pH, with the highest value recorded at 85.2 mg/g. Notably, 88.2 % of this maximum adsorption was achieved within 60 min, indicating a rapid adsorption process. Kinetic studies indicated that the adsorption process best fits pseudo-second-order kinetics, while the Freundlich model, with an R² value of 0.95, suggests a chemisorption mechanism. The developed wool-alginate-gum hydrogel composite has shown to be a promising candidate for the removal of Pb²⁺ ions from wastewater.

Keywords

• Sodium alginate
• Waste wool
• Gum arabic/xanthan gum
• Hydrogel composite
• Heavy metal adsorption
• Wastewater treatment