Work

Enhancing Cs retention in superabsorbent polymers via preferential Ca removal by CO2 bubbling in fly-ash aqueous systems

Year: 2026

Type: article

Abstract: In this study, we aimed to safely treat fly ash generated during the incineration-based volume reduction of 137 Cs-contaminated waste from the Fukushima Daiichi Nuclear Power Plant accident by applying SAP in the fly-ash washing process. To enhance the Cs⁺ retention capacity of SAP, we investigated the removal of the interfering element Ca from fly-ash aqueous solutions by inducing CaCO 3 precipitation via CO 2 bubbling. When CO 2 bubbling adjusted the pH of the solution to an appropriate range, Ca 2+ concentrations decreased through CaCO 3 precipitation, thereby decreasing the distribution coefficient for Ca and enhancing that for Cs. This method is advantageous because it does not require chemical modification of SAP and avoids increasing the electrolyte concentration, which would otherwise reduce SAP water-absorption capacity.

Source: Journal of Radioanalytical and Nuclear Chemistry

DOI: 10.1007/s10967-026-11051-3

Authors: Shogo Higaki, Toru Oishi

Institutions: The University of Tokyo, Nippon Steel (Japan)

Language: English

Topic: Chemical Synthesis and Characterization

Subfield: Waste Management and Disposal

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $3,790