A Magnetic Sorbent for Radiocesium and Radiostrontium Removal from Clay and Soil Suspensions

A magnetic sorbent based on a mixture of magnetic iron and nickel oxides, and specific surface activation by ferrocyanide solution for enhancement of cesium adsorption is described. After equilibration of clay or soil suspension with the magnetic sorbent, the latter can be removed with exchangeable radiocesium and radiostrontium by means of magnetic separation. The distribution coefficients of the order 2·103 l/kg for cesium and 5·103 l/kg for strontium were determined. The efficiency of the sorbent was investigated in a 1% montmorillonite or soil suspension. At a soil:sorbent ratio 1:1–1:6 in the suspension, the fraction of exchangeable radiocesium in soil at a 2 hours contact was diminished from 56–59% to 48–12%, the decontamination factor of both the mobile cesium and strontium is about 3. The multistage process and sorbent recycling need further investigation.