Tannic acid-assisted prussian blue anchoring on membranes for rapid and recyclable removal of cesium

As an effective adsorbent, prussian blue (PB) has been used to selectively eliminate radioactive cesium from the complex and change wastewater. Multiple attempts were introduced to refrain from the recovery difficulty of direct application of PB. This study designed a novel strategy of tannic acid (TA) assisted multilayer PB immobilization on a commercial substrate for cesium adsorption. As an effective binder, TA-Fe was successfully applied to immobilize and disperse PB to increase the number of active particles. The resulting composite membrane (MTA-PB) showed excellent cesium selectivity with a high Kd value of 8986 mL/g in geothermal water and maintained its cesium adsorption ability after 5 cycles. Compared with the reported PB powder, the loaded PB gave full play to the adsorption performance. The convenient fabrication method and effective removal of Cs from complex solutions demonstrated that the MTA-PB has excellent potential for practical application in low wastewater concentrations.