Migration of strontium, cesium, europium and uranium from poly(methyl styrene)- and polystyrene - phosphate composites prepared using gamma radiation

Composites consisting of natural phosphate powder and two monomers (styrene or methyl styrene) have been prepared by means of gamma irradiation. The polymerization reaction was followed up using a thermogravimetric analyzer (TGA) to determine the conversion of the polymerization. Differential scanning calorimeter (DSC) was used to locate and determine the glass transition temperature (Tg) of the prepared samples. The distribution of 137Cs, 152Eu, 85Sr and 238U in a solid-aqueous system, composites of phosphate-poly(methyl styrene) and of phosphate-polystyrene in contact with groundwater, was investigated using alfa-spectrometry and fluorometry. The effects of contact time, pH, and the concentration of concurrent element (Ca) were studied. The results were compared with earlier results with phosphate alone in the solid phase. The ability of the produced composites to keep the studied radioisotopes in the solid phase is much higher than in the mineral phosphate. This improvement is more remarkable for strontium and cesium than for europium and uranium, due to their high element ratio in the solid phase in phosphate experiments.