Uptake of U(VI) from aqueous media by magnetic Schiffʹs base chitosan composite

Schiffʹs base chitosan composite with magnetic properties has been prepared and investigated. The modification process took place through the reaction between chitosan and polymeric Schiffʹs base of thiourea/glutaraldehyde in the presence of magnetite. The sorption characteristics of the composite towards UO 2 2 + at different experimental conditions were carried out by means of batch and column methods. The composite showed high affinity and fast kinetics for the sorption of UO 2 2 + ions, the sorption capacity reached 2.32 mmol/g at 25 °C. Various parameters such as pH, agitation time, UO 2 2 + concentration and temperature had been studied. The kinetics and thermodynamic behavior of the sorption reaction were defined. These data indicated an exothermic and spontaneous sorption process, and kinetically followed pseudo-second order model, Fickian diffusion low and Elovich equation. The uptake of UO 2 2 + was slightly influenced by the increase of ionic strength. Breakthrough curves for the removal of UO 2 2 + were studied at different flow rates and bed heights. The critical bed height for the studied column was found to be 0.656 cm at flow rate of 4 mL/min. Hydrochloric acid (0.2 M) was used for desorbing UO 2 2 + from loaded composite: desorption yield as high as 97% was obtained.