Sonochemical synthesis of guar gum - Zirconium phosphate composite for efficient capture of uranium from water

The increasing presence of uranium as a radionuclide contaminant in water is a threat to human health and the environment. Sonication-assisted crosslinking of guar gum, a biopolymer, is carried out with zirconium phosphate to form an adsorbent (GG@ZrP) for the removal of uranium from water. The surface characteristics, functionalities, and thermal stability of the composite were established using various analytical and spectral tools. Langmuir, Freundlich, and Sips models were used to evaluate the batch adsorption parameters. The adsorbent exhibited an excellent Langmuir adsorption capacity of 500 mg g^-1 towards adsorption of uranium at pH 6. The adsorption was endothermic (ΔH, 22.63 kJ mol^-1) and followed pseudo-second order kinetics. The synergistic influence of hydroxyl-rich guar gum and phosphate moieties resulted in efficient binding of uranium. With a high selectivity towards interfering cations and anions and applicability over a good range of pH, this adsorbent is a promising candidate for uranium remediation from water.