Nanoconfined Fe(II) releaser for long-term arsenic immobilization and its sustainability assessment

• Published in: Water research (Oxford) Vol. 260; p. 121954
• Main Authors: Liu, Kai, Li, Fangbai, Zhu, Zhenlong, Fang, Liping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.08.2024
• Subjects: Electron transfer; Life cycle assessment; Nanoconfinement; Reactive oxygen species; Redox process; Sustainability; Life cycle assessment; Electron transfer; Reactive oxygen species; Nanoconfinement; Redox process; Sustainability
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2024.121954

•A nanoconfined ZVI/porous carbon was developed for arsenic immobilization.•The nanoconfined ZVI@PC enables the long-term release of Fe(II) and electrons.•The longevity and reactivity of ZVI@PC is considerably greater than commercial ZVI.•Environmental sustainability of ZVI@PC for soil remediation was revealed. Ferrous (Fe(II))-based oxygen activation for pollutant abatements in soil and groundwater has attracted great attention, while the low utilization and insufficient longevity of electron donors are the primary challenges to hinder its practical applications. Herein, we propose a nanoconfined Fe(II) releasing strategy that enables stable long-term electron donation for oxygen activation and efficient arsenic (As) immobilization under oxic conditions, by encapsulating zero-valent iron in biomass-derived carbon shell (ZVI@porous carbon composites; ZVI@PC). This strategy effectively enhances the generation of reactive oxygen species, enabling efficient oxidation and subsequent immobilization of As(III) in soils. Importantly, this Fe(II) releaser exhibits strong anti-interference capability against complex soil matrices, and the accompanying generation of Fe(III) enables As immobilization in soils, effectively lowering soil As bioavailability. Soil fixed-bed column experiments demonstrate a 79.5 % reduction of the total As in effluent with a simulated rainfall input for 10 years, indicating the excellent long-term stability for As immobilization in soil. Life cycle assessment results show that this Fe(II) releaser can substantially mitigate the negative environmental impacts. This work offers new insights into developing green and sustainable technologies for environmental remediation. [Display omitted]