Synthesis, Kinetic Modeling, and Thermodynamic Evaluation of Textile Waste-Derived CMC/NCC Nanocomposites for Efficient Neodymium Adsorption

This study investigated the adsorption efficiency of neodymium (Nd) ions using carboxymethyl cellulose (CMC)-nanocrystalline cellulose (NCC) biopolymers synthesized from textile waste. Microcrystalline cellulose (MCC) was obtained via acid hydrolysis, followed by NCC synthesis using a basic reaction. The materials were characterized using FT-IR, SEM, and XRD analyses. Key parameters such as pH, initial Nd concentration, agitation time, and temperature were optimized, revealing effective adsorption of Nd by CMC biopolymer. Thermodynamic analysis showed the process was endothermic and spontaneous, fitting Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. Kinetic analyses revealed a two-stage adsorption mechanism involving rapid initial physical adsorption followed by chemisorption, with the pseudo-second-order model providing the best fit to experimental data and confirming the dominant role of chemical interactions in Nd (III) immobilization onto the CMC/NCC nanocomposite. The porous hydrogel structure of CMC enhances adsorption performance. In conclusion, CMC-NCC biopolymer offers a cost-effective, eco-friendly, and efficient alternative for Nd ion removal from aqueous solutions.