Selective Removal of Cs+ From Contaminated Water Using Silicon Bead/Potassium Copper Ferrocyanide Composites in Fixed-Bed Column

By using a column elution method, potassium copper ferrocyanide(Cu-PBA) was in situ loaded on silicon bead(SiO2) column packing, thereby yielding a SiO2/Cu-PBA fixed bed column. The characterizations of SiO2/Cu-PBA by SEM-EDS, FTIR, XRD and N2 adsorption-desorption isotherm techniques confirms the successful loading of Cu-PBA on SiO2. In batch experiments, it is found that the maximum adsorption capacity of SiO2/Cu-PBA for Cs+ is around 4.0 mg/g, and it needs 30 min to reach equilibrium adsorption. Then, the adsorpion behavior of Cs+ by the SiO2/Cu-PBA fixed bed was systematically studied, including the impacts of various operating parameters such as bed depth, bed diameter, flow rate, and influent Cs+ concentration. In the optimized fixed bed system, the adsorption behaviors of Cs+ and coexisting metal ions(K+, Na+, Ca2+, and Mg2+) by SiO2/Cu-PBA and cation-exchanged resin were compared in both simulated groundwater and seawater. The efficient and highly selective removal of Cs+ by SiO2/Cu-PBA is addressed as well as the inefficiency of cation-exchanged resin in simulated seawater. Therefore, the SiO2/Cu-PBA composite will have great application prospects in the continuous removal of Cs+ from various Cs+-contaminated environmental water media.