Efficient sorption of zirconium (IV) from zircon leachate using a carboxymethyl cellulose based sorbent

In this study, a hydrogel carboxymethyl cellulose-polyvinyl alcohol-fumaric acid (CPF hydrogel) composed of Sodium Carboxymethyl Cellulose (CMC) and Polyvinyl Alcohol (PVA) with the ratio 3:1 and Fumaric Acid was synthesized through the wet chemical method and evaluated for the sorption of Zr (IV) ions from acidic leachate solution. The CPF hydrogel was characterized using FT-IR, SEM and EDX. The results confirmed its porous structure and surface functionality that promoted the effective metal ion sorption. Batch experiments were conducted to investigate the effects of contact time, initial concentration, V/m ratio, temperature, and pH on Zr (IV) extraction. Equilibrium was reached within 90 min at pH 1, V/m = 0.3, and 20 °C. The maximum sorption capacity was 239.7 mg g^- 1. The sorption kinetics followed the pseudo-n^th-order model, while equilibrium data best fit the Dubinin-Radushkevich (D-R) isotherm models, indicating the chemisorption nature of the sorption process. Thermodynamic analysis revealed that the sorption process is spontaneous and endothermic. Desorption studies showed that 0.2 M H₂SO₄ was an effective eluent to recover about 90% Zr (IV). These findings highlight CPF hydrogel as a promising, cost-effective material for the selective recovery of Zr (IV) from acidic leachates, offering potential applications in metal separation and purification processes.