Application of Liquid Solid Semi-moving Bed to Fractionation of Cesium Ion in Wastewater*

A liquid solid semi-moving bed with non-mechanical particle transport system is proposed and used for fractionation of cesium ion in wastewater. The particle transport system, which consists of a suction chamber, a mixing chamber, a nozzle and a riser tube, is designed to be controlled completely by hydraulic force. Experiments show that continuous feeding and discharging of resin can be realized by the transport system. The removal of cesium ion from wastewater is realized. The concentration of cesium ion in effluent liquid remains below 0.1g · L−1 (the initial concentration is 5.3g · L−1) during the 73 hours' experiment. The average exchange capacity of resin discharged from the bed is 0.57 mmol · (g dry resin)−1, which is close to the saturated capacity of 0.65 mmol · g−1. And it is also proved that the non-homogeneity of particle vertical velocity along the radial direction can seriously influence the ion-exchange process.