Recovery of radioactive cesium using nickel hexacyanoferrate as an electrically switched ion exchanger

A combination of conventional ion exchange and electrochemical processes was conducted in production of electrically switched nickel hexacyanoferrate ion exchanger, specially used for 134Cs recovery. The deposited films were physically characterized by energy dispersive x-ray spectroscopy and x-ray diffraction techniques. 134Cs uptake was controlled by modulation of the ion exchanger potential in batch and flow systems. The deposited nickel hexacyanoferrate ion exchange film was found hydro-mechanically stable up to 130 bed volume/h. The ion uptake was about more than 90% achieved after 15 h of equilibrium . The reduced film state showed higher performance than the oxidized one in presence and absence of Na+ ions with different concentrations. The breakthrough of the electrically switched ion exchange (ESIX) process was also conducted in different stacking of electrodes cells. Three and six stacked electrodes assemblies showed longer breakthroughs than single electrode assembly at the same operating conditions. In vertical cell, representing larger scale tests, higher concentrations (60 ppm Cs+) could be successfully treated.