Offshore concentration of caesium radioisotopes from large volume seawater samples using KNiFC-PAN.

A method for caesium concentration from North Sea and Baltic Sea seawater samples was tested and optimised for offshore concentration of radiocaesium and seawater volumes up to 150 L. The composite ion-exchanger PotassiumNickel Hexacyanoferrate in a Polyacrylnitrile binding matrix (KNiFC-PAN) with 80% of powdered KNiFC per gram of dry residue was used for this study. The optimised method achieved recoveries of around 99% with a bed volume (BV) of 50 mL of KNiFC-PAN and average flow rates of seawater of around 182 BV per hour (e.g. 9.1 L per hour).