Application of potassium titanium ferrocyanide for the removal of uranium from aqueous solution. Efficiency and mechanism

Uranium, as a highly toxic radioactive contaminant existing in mine wastewater and contaminated groundwater, has sparked widespread alarm in recent years. This work demonstrates the technological possibility of recovering uranium from aqueous solutions using potassium titanium ferrocyanide (KTiFC). The adsorption behavior, kinetics, isotherms, and thermodynamic investigations were systematically examined. The maximum capacities were achieved at pH3.8, and KTiFC was proven to be stable across a wide pH range. The adsorption process was best represented by a pseudo-second order rate equation and the Langmuir isotherm model, with 90% of the uranium eliminated in 60 min. The adsorption process was endothermic and spontaneous, adsorption efficiency of uranium is highly related to water temperature. The integrated analysis of EDS, ICP-OES, FTIR and XPS suggested that chemisorption combined with ion exchange between K and U can describe the adsorption mechanism of uranium sorption on KTiFC. This study points the way toward developing effective and low-cost materials with practical functionality for uranium extraction from polluted water. (author)