National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China.
Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan.
Molecules. 2022 Jul 18;27(14):4570. doi: 10.3390/molecules27144570.
Geopolymers, as a kind of inorganic polymer, possess excellent properties and have been broadly studied for the stabilization/solidification (S/S) of hazardous pollutants. Even though many reviews about geopolymers have been published, the summary of geopolymer-based S/S for various contaminants has not been well conducted. Therefore, the S/S of hazardous pollutants using geopolymers are comprehensively summarized in this review. Geopolymer-based S/S of typical cations, including Pb, Zn, Cd, Cs, Cu, Sr, Ni, etc., were involved and elucidated. The S/S mechanisms for cationic heavy metals were concluded, mainly including physical encapsulation, sorption, precipitation, and bonding with a silicate structure. In addition, compared to cationic ions, geopolymers have a poor immobilization ability on anions due to the repulsive effect between them, presenting a high leaching percentage. However, some anions, such as Se or As oxyanions, have been proved to exist in geopolymers through electrostatic interaction, which provides a direction to enhance the geopolymer-based S/S for anions. Besides, few reports about geopolymer-based S/S of organic pollutants have been published. Furthermore, the adsorbents of geopolymer-based composites designed and studied for the removal of hazardous pollutants from aqueous conditions are also briefly discussed. On the whole, this review will offer insights into geopolymer-based S/S technology. Furthermore, the challenges to geopolymer-based S/S technology outlined in this work are expected to be of direct relevance to the focus of future research.
地质聚合物作为一种无机聚合物，具有优异的性能，已广泛研究用于稳定/固化（S/S）危险污染物。尽管已经发表了许多关于地质聚合物的评论，但关于地质聚合物基 S/S 各种污染物的总结尚未得到很好的开展。因此，本文全面总结了地质聚合物对危险污染物的 S/S 作用。涉及并阐明了典型阳离子（如 Pb、Zn、Cd、Cs、Cu、Sr、Ni 等）的地质聚合物基 S/S。总结了阳离子重金属的 S/S 机制，主要包括物理包裹、吸附、沉淀和与硅酸盐结构的键合。此外，与阳离子相比，由于它们之间的排斥作用，地质聚合物对阴离子的固定能力较差，浸出率较高。然而，一些阴离子，如硒或砷的含氧阴离子，已经通过静电相互作用被证明存在于地质聚合物中，这为增强地质聚合物基 S/S 对阴离子的能力提供了一个方向。此外，关于地质聚合物基 S/S 有机污染物的报道很少。此外，还简要讨论了为从水相中去除危险污染物而设计和研究的基于地质聚合物的复合材料的吸附剂。总的来说，本文将为地质聚合物基 S/S 技术提供新的见解。此外，本文概述的地质聚合物基 S/S 技术面临的挑战有望直接与未来研究的重点相关。
