Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, South Korea.
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, South Korea.
J Hazard Mater. 2016 Nov 15;318:339-346. doi: 10.1016/j.jhazmat.2016.07.003. Epub 2016 Jul 4.
The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10(3) and 10(4), respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior.
本研究考察了地质聚合物固化体对铯和锶浸出行为的物理屏障效应。使用粉煤灰基地质聚合物和矿渣混合地质聚合物作为固化剂。根据 ANSI/ANS-16.1 评估了地质聚合物中铯和锶的浸出行为。与波特兰水泥相比，粉煤灰基地质聚合物中铯和锶的扩散系数分别降低了 10(3)和 10(4)倍，表现出显著提高的固定化性能。粉煤灰基地质聚合物的抗浸出性与粉煤灰的类型无关，基本保持不变。水溶性铯和锶离子的扩散系数与粘结剂的临界孔径高度相关。粉煤灰基地质聚合物的临界孔径明显小于波特兰水泥和矿渣混合地质聚合物；因此，其阻止核素扩散的能力（物理屏障效应）更强。
