Nanocomposite SiEA-KNiFe sorbent — Complete solution from synthesis through radiocesium sorption to vitrification using the sol–gel method

•Novel nanocomposite silica/potassium-nickel hexacyanoferrate/ethanolamine (SiEA-KNiFe) was synthesised and characterized.•The SiEA-KNiFe sorbent was employed as radiocesium adsorbent in batch and fixed-bed process.•The SiEA-KNiFe exhibited high selectivity for cesium removal in the presence of competitive ions.•Sol–gel method for spent sorbent vitirification was elaborated.•Cesium leaching test confirmed stable embedment of the spent sorbent in the glass matrix.