Effective sorption of U(VI) from chloride solutions using zirconium silico-tungstate matrix

A zirconium silico-tungstate gel material (ZiSiW) was prepared using an inexpensive precipitating technique to be used as a sorbent. The uptake capacity of ZrSiW sorbent from uranium chloride feed solution was found to be 76 mg/g adsorbent. The Optimum adsorption process was carried out using conditions; chloride feed solution of 810 mg/L U(VI) and pH 4, solid adsorbent to chloride aqueous solutions of 1/100 and contact time of 20 minutes at 45°C. The equilibrium adsorption results were fitted well with Langmuir model, which elucidated the sorption process and provided an understanding of the sorption mechanism. The adsorption reaction was found to follow the pseudo-second-order kinetics, and the calculated adsorbate in the adsorbent at equilibrium fitted well with the experimental results. Obtained thermodynamic parameters indicated that the adsorption process was endothermic nature and the adsorption process was more favourable at high temperatures. Characterisation of the loaded adsorbent using FT-IR and EDAX analysis proved the uranium adsorption upon the ZrSiW gel.