Nuclear energy serves as a vital low‑carbon energy source, while radioactive wastewater containing soluble 137 Cs and 90 Sr poses severe ecological and health risks. These radionuclides feature long half‑lives and strong environmental mobility. Traditional treatment approaches divide pollutant adsorption and subsequent solidification into independent procedures. Such workflows suffer from poor physicochemical compatibility between adsorbents and solidification matrices, complicated operation procedures and large volumes of secondary radioactive waste. It is urgent to develop robust functional materials combining efficient dynamic adsorption, radiation tolerance and intrinsic self‑solidification capacity.
Recently, a team of material scientists led by Kaituo Wang from Guangxi University, China reported novel radiation‑resistant sodalite microspheres (GXU‑SODs) via a facile geopolymer‑based non‑hydrothermal conversion strategy, which integrates the removal and permanent in‑situ immobilization of Cs + and Sr 2+ .
This work not only uncovers the atomic‑scale adsorption and thermally‑driven lattice immobilization mechanism of Cs + and Sr 2+ on GXU‑SODs, but also provides a scalable, template‑free non‑hydrothermal strategy to fabricate high‑strength radiation‑resistant zeolite microspheres for radioactive wastewater safe remediation.
The team published their work in Journal of Advanced Ceramics on September 16, 2026.
“In this report, we synthesized well‑crystallized sodalite micrspheres (GXU-SODs) by tuning the n(Na 2 O)/n(Al 2 O 3 ) molar ratio and curing time, and residual amorphous geopolymer acts as a tough binding phase,” Wang explained. “The optimized GXU‑SODs obtained a compressive strength of 13.88 MPa, which exceeds the 10 MPa threshold for fixed‑bed column continuous‑flow operation. Batch adsorption tests demonstrate the maximum adsorption capacities reach 59.64 mg·g -1 for Cs + and 56.67 mg·g -1 for Sr 2+ , following Langmuir monolayer chemisorption mechanism. Even under complex real‑water conditions such as seawater, the removal efficiency for target ions remains above 95 %. After 500 kGy irradiation, the material preserves over 96 % structural integrity and adsorption performance, confirming excellent radiation resistance.”said Wang.
“Our spent GXU‑SODs do not require additional glass or cement additives. Simple thermal treatment at 1100 ℃ triggers reconstructive phase transformation of sodalite framework. Cs + and Sr 2+ originally trapped in β‑cages are incorporated into nepheline, pollucite and stronalsite crystal lattices through strong ionic‑covalent bonding,” Wang noted. “The 28‑day normalized leaching rates of Sr 2+ and Cs + drop to 8.6×10 -7 and 2.82×10 -6 g·m -2 ·d -1 , far below the industrial regulatory standard, achieving permanent lattice‑confined immobilization rather than reversible ion exchange.” said Wang.
This scalable, template‑free synthetic route establishes an integrated “adsorption‑in‑situ immobilization” paradigm for radioactive nuclide treatment. It simplifies the whole waste‑management workflow and cuts secondary‑waste output. Nevertheless, further research is still required to explore intermediate‑temperature sintering routes to lower overall energy consumption for practical engineering deployment.
Other contributors include Min Yi, Haoyu Chen, Xinpeng Wang,Toyohisa Fujita, Xuemin Cui from the Guangxi University, China, and Lin Shao is from Nanning Normal University, China.
About Author
Kaituo Wang is an associate professor and master’s supervisor at the School of Resources, Environment and Materials, Guangxi University, China. He received his PhD degree from Guangxi University in 2016. He won the Third‑class Prize of Guangxi Science and Technology Progress Award (1st completer) and was selected for the Guangxi Bagui Youth Talent Training Program. His current research interests cover fabrication of functional nano‑adsorbents, thermal‑insulation materials, and comprehensive green utilization of solid wastes.
Funding
This work was supported by the Guangxi Natural Science Fund (Grant No. 2025GXNSFAA069185 and 2025GXNSFBA069338), National Natural Science Foundation of China (Grant No. 12105056) and Guangxi Bagui Youth Talent Training Program.
DOI LINK: 10.26599/JAC.2026.9221379
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen . JAC’s 2025 IF is 14, ranking in Top 1 (1/34, Q1) among all journals in “Materials Science, Ceramics” category, and its 2025 CiteScore is 24.6 (6/133) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
Journal of Advanced Ceramics
Non-hydrothermal synthesis of robust and radiation-resistant sodalite microspheres for effective removal and in-situ immobilization of Cs+ and Sr2+
16-Sep-2026