Insights into the adsorption capacity and breakthrough properties of uranium onto rice straw based activated carbon impregnated with ionic-liquid

This study is concerned with uranium adsorption on KOH-oxidized rice and impregnated with ionic-liquid straw-based carbon (RSK carbon) in adsorption contacting systems of batch-type and fixed bed. In this concern, experiments were performed using uranium solution of various initial concentration (100, 200, 400 mg/L); different flow rates (3, 5, 10 ml/min) and different bed depths (3 cm, 6 cm and 12 cm). The data indicated that the adsorbed uranium quantity increased with increasing bed depth, decreasing inlet concentration and flow rate. The difference between isotherm and column values is reasonable due to inherent difference in the nature of batch and continuous operations, in the batch mode equilibrium takes place and there is not continuous feeding from solution but in fixed bed, solution was fed continuously without sufficient time to attain equilibrium. Although the predictive model has been failed in producing breakthrough data on high level of accuracy, the study provided useful information's for design of fixed bed column for uranium-activated carbon system.