Zero-valent iron (ZVI) facilitated in-situ selenium (Se) immobilization and its recovery by magnetic separation: Mechanisms and implications for microbial ecology

Wang, Zhongli; Lü, Changwei; Wang, Yanming; Gomes, Rachel L.; Clarke, Coby J.; Gomes, Helena I.

Abstract

Selenium (Se(VI)) is environmentally toxic. One of the most popular reducing agents for Se(VI) remediation is zero-valent iron (ZVI). However, most ZVI studies were carried out in water matrices, and the recovery of reduced Se has not been investigated. A water-sediment system constructed using natural sediment was employed here to study in-situ Se remediation and recovery. A combined effect of ZVI and unacclimated microorganisms from natural sediment was found in Se(VI) removal in the water phase with a removal efficiency of 92.7 ± 1.1% within 7 d when 10 mg L−1 Se(VI) was present. Soluble Se(VI) was removed from the water and precipitated to the sediment phase (74.8 ± 0.1%), which was enhanced by the addition of ZVI (83.3 ± 0.3%). The recovery proportion of the immobilized Se was 34.2 ± 0.1% and 92.5 ± 0.2% through wet and dry magnetic separation with 1 g L−1 ZVI added, respectively. The 16 s rRNA sequencing revealed the variations in the microbial communities in response to ZVI and Se, which the magnetic separation could potentially mitigate in the long term. This study provides a novel technique to achieve in-situ Se remediation and recovery by combining ZVI reduction and magnetic separation.

Citation

Wang, Z., Lü, C., Wang, Y., Gomes, R. L., Clarke, C. J., & Gomes, H. I. (2024). Zero-valent iron (ZVI) facilitated in-situ selenium (Se) immobilization and its recovery by magnetic separation: Mechanisms and implications for microbial ecology. Journal of Hazardous Materials, 473, Article 134591. https://doi.org/10.1016/j.jhazmat.2024.134591

• Journal Article Type: Article
• Acceptance Date: May 10, 2024
• Online Publication Date: May 14, 2024
• Publication Date: Jul 15, 2024
• Deposit Date: May 20, 2024
• Publicly Available Date: May 15, 2025
• Journal: Journal of Hazardous Materials
• Print ISSN: 0304-3894
• Electronic ISSN: 1873-3336
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 473
• Article Number: 134591
• DOI: https://doi.org/10.1016/j.jhazmat.2024.134591
• Public URL: https://nottingham-repository.worktribe.com/output/35141459
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0304389424011701?via%3Dihub