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.

中文翻译：

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用于砷长期固定的纳米Fe(II)释放剂及其可持续性评估


二价铁（Fe(II)）基氧活化用于土壤和地下水污染物减排引起了广泛关注，而电子供体利用率低和寿命不足是阻碍其实际应用的主要挑战。在此，我们提出了一种纳米限制的 Fe(II) 释放策略，通过将零价铁封装在生物质衍生的碳壳 (ZVI@porous碳复合材料；ZVI@PC)。该策略有效地增强了活性氧的产生，从而实现了土壤中 As(III) 的有效氧化和随后的固定化。重要的是，这种Fe(II)释放剂对复杂的土壤基质表现出很强的抗干扰能力，并且伴随生成的Fe(III)能够使As固定在土壤中，有效降低土壤As的生物有效性。土壤固定床柱实验表明，通过 10 年的模拟降雨输入，出水中的总砷减少了 79.5%，表明土壤中砷固定化具有优异的长期稳定性。生命周期评估结果表明，这种 Fe(II) 释放剂可以显着减轻对环境的负面影响。这项工作为开发用于环境修复的绿色和可持续技术提供了新的见解。