Immobilization of high-concentration antimony by schwertmannite: Structural incorporation and mineral stability

作者：Yiming Zhang, Zhiwei Sun, Ru Wang, Hua Li, Xiaomeng Wang, Guanyu Zheng · 发表于：Chemical Engineering Journal Advances · 年份：2025 · DOI：10.1016/j.ceja.2025.100780 · 被引用次数：3 · 研究领域：Arsenic contamination and mitigation、Mine drainage and remediation techniques、Metal Extraction and Bioleaching

Antimony (Sb) is a priority pollutant frequently co-occurring with arsenic (As) in mining-impacted environments. The speciation, mobility, and fate of Sb in the environment are intricately linked to its interactions with iron minerals at micro-interfaces. This study investigated the immobilization behavior and mechanisms of Sb(III) and Sb(V) at relatively high environmental concentrations onto schwertmannite (Sch), a common iron mineral prevalent in mining areas, with ferrihydrite (Fh) serving as a reference. Batch adsorption experiments demonstrated that Sb(V) adsorption was favored at low pH, whereas Sb(III) adsorption increased significantly at higher pH levels. The maximum adsorption capacities of Sch for Sb(V) and Sb(III) was determined to be 100.8 mg/g and 111.1 mg/g, respectively, at pH 7.0. Sequential extraction and spectroscopic analyses revealed that Sb immobilization on Sch occurred through hydroxyl complexation, structural incorporation, and surface precipitation mechanisms, with sulfate exchange also contributing to the immobilization of Sb(V). Additionally, Sb adsorption increased the mineral stability, enhancing the resistance to acidic dissolution. The co-existing As influenced Sb adsorption, with As(III) exerting a stronger inhibitory effect on Sb(III) adsorption. These findings reveal the immobilization behavior and mechanisms of high-concentration Sb by Sch, emphasizing the critical roles of structural incorporation and surface precipitation in Sb immobiliz...