Removal of cesium from liquid radioactive waste by in situ electrochemical synthesis of cesium zinc ferrocyanide

Cesium ion in the simulated liquid radioactive waste was treated with cesium zinc ferrocyanide (CsZnFC) precipitate synthesized by in situ electrochemical synthesis method (ISESM) in this study. The best removal rate of Cs+ was 99.42%, and the residual Cs+ in the effluent was 29.13 μg L‐1 under the optimal experimental conditions of initial pH (pHint) of 7.0, reaction temperature (T) of 35 °C, current density (J) of 0.7 mA cm−2, electrolytic time (t) of 30 min, and molar ratio of [Fe(CN)6]4- to Cs (RFCN/Cs) of 1.0. The synthesized precipitate was characterized by SEM-EDS, XRD and FT-IR. The precipitated particles are cubic with a particle size of around 190 nm. The XRD pattern shows that the phase composition of the synthesized compound is Cs2Zn[Fe(CN)6], and the absorption peaks of O–H bonds, C–N bonds, and C–Fe bonds appear in IR spectrum. The method of in situ electrochemical synthesis of CsZnFC is promising for the treatment of liquid radioactive wastes. [Display omitted] •The cesium zinc ferrocyanide synthesized by the in-situ electrochemical method has an excellent removal effect on Cs+.•The synthesized precipitate has a face-centered cubic crystalline structure and the chemical formula is Cs2Zn[Fe(CN)6].•It can be removed Cs+ from liquid radioactive waste with higher efficiency.