Synthesis and application of chitosan and orange peel biocomposites for cadmium (II) removal from water

Sustainability-based approaches have encouraged the scientific community to address the development and synthesis of materials capable of removing contaminants from water, prioritizing the use of environmentally friendly raw materials and methods. In this study, we describe the synthesis of a composite by ionic crosslinking, using chitosan as a polymeric matrix and orange peel (1:3). The composites demonstrated structural stability, evaluated through swelling equilibrium and soluble fraction at pH 3, 5, and 7. At these same pH values, the adsorption capacity of Cd(II) was evaluated, obtaining a maximum capacity of 122.93 mg g⁻¹ at pH 7. The adsorption of Cd(II) on the composites was attributed to electrostatic attraction and chemisorption mechanisms, which were corroborated by the morphological, textural and physicochemical characterization of the material. According to the results, the chitosan and orange peel composites present potential characteristics for the removal of contaminants such as Cd(II) in water.