Mass transport modeling of Cs(I) through hollow fiber supported liquid membrane containing calix-[4]-bis(2,3-naptho)-crown-6 as the mobile carrier

A mathematical model is developed for the transport of cesium through hollow fiber supported liquid membrane (HFSLM) containing calix-[4]-bis(2,3-naptho)-crown-6 (CNC) as the carrier extractant in NPOE and n-dodecane mixture as diluent. The model is developed on the principle of facilitated diffusional transport mechanism with laminar flow inside the tubular region in the fiber with all the flow rate conditions. It predicts the rate of transport of cesium from feed solution under various experimental conditions and system compositions. Simultaneously, experiments were performed taking varying concentrations of cesium nitrate in 3 M HNO3 as the feed solution and distilled water as the strip and the cesium transport rates were measured. Both the results were plotted and a good level of agreement is seen between predicted and experimental data points. Similar studies were carried out as a function of carrier extractant concentration and varying feed and strip flow rates. Reasonable agreement between the experimental and predicted data suggested validity of the developed model.

► Cs recovery from radioactive waste is one of the most challenging issues.
► Calix-crown ligands have been found to be highly selective for Cs.
► SLM based methods are ‘green’ alternatives to the solvent extraction methods.
► Mathematical modeling of Cs(I) transport across hollow fiber membranes containing calix-crown extractant is done.
► The modeling studies will be beneficial for solving scale up issues.