Adsorptive extraction of uranium(VI) from aqueous phase by dolomite

Natural dolomite rock collected from Chhitapandariya, Jaijaipur, Janjgir Champa region of Chhattisgarh, India, was tested for its uranium(VI) removal efficiency from aqueous phase. Adsorption characteristics relating to powdered dolomite rock were examined by conducting batch experiments under various adsorption parameters like pH, concentration, contact time, adsorbent dose, along with temperature. At 303 K when the optimum experimental conditions were employed, the removal of 78.8% of uranium(VI) was attained. The impact of temperature upon uranium(VI) extraction by dolomite adsorbent was studied at 303, 313, and 323 K and thermodynamic quantities (the change in Gibbs free energy, enthalpy and entropy of adsorption) were evaluated. The adsorption mechanism was specified by Langmuir adsorption isotherm and pseudo-first-order kinetics. The results suggested that natural dolomite rock has remarkable capability of treatment of uranium(VI) contaminated water.