Cobalt and hydroxy magnetite doped Arabic gum as mesoporous composite for efficient removal of uranium (VI) from aqueous solution.

Uranium contamination in aquatic environments poses serious risks to both ecosystems and human health, necessitating efficient and sustainable removal technologies. The present work investigates the application of gum Arabic activated magnetite mesoporous particles (GA-MMPs) and gum Arabic activated magnetite-cobalt mesoporous particles (GA-CoMMPs) for uranium adsorption from aqueous solutions. The sorbents were characterized using various techniques including FTIR, SEM-EDX, BET surface analysis, and zeta potential measurements to explore the structural and morphological features of the sorbents. Batch adsorption experiments were conducted to evaluate the effects of pH, sorbent dose, contact time, initial uranium concentration, and temperature on the adsorption process. The adsorption kinetics followed a pseudo-second-order model, while the Sips isotherm best described the equilibrium data. Thermodynamic studies revealed that the adsorption process was spontaneous and endothermic. The GA-CoMMPs demonstrated superior performance compared to GA-MMPs, attributed to the incorporation of cobalt ions, which improved surface properties and binding site availability. The maximum adsorption capacities of GA-CoMMPs and GA-MMPs were 70.6 mg g⁻¹ and 55.9 mg g⁻¹, respectively at pH 4, sorbent dose of 1 g/L. The sorbents showed excellent reusability over five adsorption-desorption cycles using sulfuric acid as the eluent. A case study using industrial wastewater demonstrated the sorbents' effectiveness and selectivity for uranium removal in complex matrices. The novelty of this work lies in the eco-friendly synthesis of a cobalt-doped magnetic mesoporous composite based on Arabic gum, combining high selectivity, recyclability, and adsorption efficiency, and positioning it as a strong candidate for real-world uranium remediation applications.