Thermal activation of kaolinite titanium hydroxide composite for uranium adsorption from aqueous solutions

Abstract

AbstractIn the present study, thermally treated kaolinite at 600 ºC was incorporated with titanium hydroxide produced from ilmenite to prepare a novel, low-cost and a promising adsorbent (KT). Different analytical techniques such as FTIR, EDS, SEM were used to determine its structural analysis. Its applicability for uranium uptaking and desorption from its aqueous solutions was investigated by varying controlling conditions including pH, shaking time, initial concentrations, temperature and KT dose weight. Untreated kaolinite showed zero loading capacity and adsorption efficiency towards uranium ions, on the contrary thermal activation and incorporation with Ti(OH)4 improved its performance. Batch results for adsorption experiments showed that loading capacity of (KT) reached 160mgg−1; at pH 5, after only 20 min shaking time. Uranium adsorption process was much closer to a traditional Langmuir adsorption isotherm with a theoretical saturation capacity of 161.3mgg−1. From thermodynamics data, the adsorption process is endothermic in nature which emphasized by elevating temperature has an enhancement effect on uranium adsorption with uptake of 205 mgg−1 at 60 ℃. Uranium adsorption was kinetically fitted with the pseudo-second-order model. KT composite has a high applicability and reusability due to its high resistance to extreme acidity levels.