Enhanced cesium decontamination in water reservoirs using natural geosorbents with optimized dispersion

This study investigated the efficiency of natural mineral-based sorbents, specifically zeolites, in removing cesium (Cs) and optimizing sorbent dispersion for enhanced decontamination of water bodies of different scales. Batch sorption experiments on seven types of clay minerals revealed that powder-type zeolite (P-Zeo) exhibited remarkable Cs sorption efficiency. The maximum sorption capacity of P-Zeo was 1.35 × 108 μg kg−1, and it achieved nearly 99 % removal efficiency under various initial Cs concentrations, temperatures, gamma radiation, and the presence of competitive cations such as K and Na. Then, P-Zeo was modified into foam-type zeolite (F-Zeo) to enhance the horizontal dispersion of the material in surface water. Comparative application tests in water tanks and a natural reservoir demonstrated that the horizontal dispersion of F-Zeo was 50 % better than that of P-Zeo due to its foam formulation, leading to wider, more effective decontamination coverage. Additionally, F-Zeo remained suspended longer than P-Zeo in water bodies, which enhanced its Cs sorption effectiveness and maintained its consistent removal pattern over a broader area. These results highlight the need to develop advanced decontamination strategies that leverage the unique properties of zeolites to protect water resources from radiological contamination. •Clay minerals are effective medium to decontaminate cesium in a large water body.•Horizontal dispersion of natural geosorbent is enhanced by foam-type processing.•Zeolites achieved 99 % Cs removal efficiency under diverse environmental conditions.•The foam-type zeolite lasts a long time in a water body, and improves cesium removal rate.