A Novel Biocomposite of Diethylaminoethyl Cellulose Fiber Incorporated Fish Scale Derived Hydroxyapatite for Lead (II) Removal: Experimental and Mechanistic adsorption

This research introduces a novel biocomposite synthesized by incorporating diethylaminoethyl cellulose (DEAE-C) with natural hydroxyapatite (Hap) derived from fish scales, designed for the adsorption of Pb(II) ions from water. Comprehensive characterization was performed using FTIR, XRD, SEM-EDS, TGA, and BET analyses to elucidate the interactions and complexation between Hap and DEAE-C. Batch adsorption experiments assessed the effect of contact time, initial Pb(II) concentration, pH, and temperature. Adsorption equilibrium conformed to the Langmuir model, with a maximum uptake (qmax) of 147.7 mg g−1 at 25°C. Kinetic studies indicated a pseudo first order model for adsorption, while thermodynamic analysis revealed the process to be endothermic and spontaneous. Mechanistic insights, derived from theoretical calculations and XPS analysis, identified ion exchange and electrostatic interactions as the predominant mechanisms. The DEAE-C–Hap composite exhibited outstanding adsorption properties, underscoring its potential for practical applications in wastewater treatment. In conclusion, the cellulose composite containing natural hydroxyapatite exhibited excellent adsorption properties for heavy metal remediation.