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

• Published in: Groundwater for sustainable development Vol. 11; p. 100424
• Main Authors: Diwan, Vijita, Sar, Santosh Kumar, Biswas, Supriya, Lalwani, Rajesh
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2020
• Subjects: Aqueous phase; Dolomite; Extraction; Uranium(VI); Extraction; Dolomite; Uranium(VI); Aqueous phase
• ISSN: 2352-801X; 2352-801X
• DOI: 10.1016/j.gsd.2020.100424

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.
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•U(VI) removal efficiency by dolomite has been investigated by batch technique.•The adsorption mechanism involved chemical adsorption.•U(VI) removal from aqueous solutions by dolomite is due to the electrostatic attraction between U(VI) and HCO3− ions.•Spontaneity of adsorption process is confirmed by negative values of Gibbs free energy change.