Hu Yang, Tang Jinping, Fei Yingxiang, Shang Jing, Liu Peng, Liu Yingying
College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China.
College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China.
Environ Pollut. 2025 Feb 15;367:125639. doi: 10.1016/j.envpol.2025.125639. Epub 2025 Jan 3.
Industrial solid wastes like coal fly ash (CFA) and steel slag pose environmental challenges, while the remediation of heavy metal-contaminated water remains a global priority. This study investigates the impact of incorporating steel slag during the synthesis of CFA-based geopolymers (CFAG) on the leaching characteristics of inherent heavy metals in CFA and the Zn adsorption performance of CFAG. Leaching experiments show geopolymerization effectively immobilizes heavy metals including Fe, Cr, As, Cd, and Ti in CFA while having little effect on Mn, V, and Ni. The incorporation of 10 wt% steel slag into CFAG further enhances the stability of As but slightly elevates the release of Fe, Ti, Cu, V, and Cd. Column experiments demonstrate steel slag doped-CFAG (SCG) achieves over a 50% improvement in Zn adsorption performance compared to CFAG. Furthermore, hydrochemical analysis, X-ray absorption spectroscopy, and sequential desorption experiments reveal Zn is removed from solution by SCG primarily through surface complexation and precipitation as ZnSiO, which have suitable stability and resistance to desorption. These findings suggest doping steel slag into CFAG is a viable strategy to enhance Zn removal in contaminated water, decrease remediation costs, and effectively consume CFA and steel slag. Nevertheless, potential trade-offs concerning heavy metal leaching should be carefully evaluated to balance the performance and environmental impacts of SCG.
煤矸石（CFA）和钢渣等工业固体废物带来了环境挑战，而重金属污染水的修复仍是全球优先事项。本研究调查了在基于CFA的地质聚合物（CFAG）合成过程中加入钢渣对CFA中固有重金属的浸出特性以及CFAG对锌的吸附性能的影响。浸出实验表明，地质聚合有效地固定了CFA中的铁、铬、砷、镉和钛等重金属，而对锰、钒和镍的影响较小。向CFAG中加入10 wt%的钢渣进一步提高了砷的稳定性，但略微增加了铁、钛、铜、钒和镉的释放。柱实验表明，与CFAG相比，掺钢渣的CFAG（SCG）的锌吸附性能提高了50%以上。此外，水化学分析、X射线吸收光谱和连续解吸实验表明，SCG主要通过表面络合和沉淀为ZnSiO从溶液中去除锌，ZnSiO具有合适的稳定性和抗解吸能力。这些发现表明，向CFAG中掺杂钢渣是提高污染水中锌去除率、降低修复成本以及有效消耗CFA和钢渣的可行策略。然而，应仔细评估与重金属浸出相关的潜在权衡，以平衡SCG的性能和环境影响。
