Developments of Efficient Dithionite-Zerovalent Iron/Persulfate Systems with accelerated Fe(III)/Fe(II) Cycle for PAHs Removal in Water and Soils
Developments of Efficient Dithionite-Zerovalent Iron/Persulfate Systems with accelerated Fe(III)/Fe(II) Cycle for PAHs Removal in Water and Soils
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DOI：
10.1016/j.cej.2023.142325
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发表时间：
2023-03
影响因子：
15.1
通讯作者：
Maolin Wang;Yaling Wang;Xudong Jing;Jiahui Xu;Min Li;Qing Xie;Xiyun Cai
中科院分区：
文献类型：
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作者：
Maolin Wang;Yaling Wang;Xudong Jing;Jiahui Xu;Min Li;Qing Xie;Xiyun Cai
铁活化的过硫酸盐（PS）系统通常在地下水和土壤中遭受不良的Fe（III）/Fe（II）氧化还原循环，这是由于Fe（II）被PS相关的和天然存在的氧化性物质快速氧化。维持Fe（III）/Fe（II）氧化还原循环对于实现铁活化的过硫酸盐体系对芳族污染物（例如，多环芳烃）的地下水和土壤。本研究发现了连二亚硫酸盐（DTN）和零价铁（ZVI）的混合物对PS的协同活化作用，并开发了高效、稳定的DTN-ZVI/PS体系用于去除地下水和土壤中的多环芳烃。DTN和中间体亚硫酸盐/硫代硫酸盐在DTN-ZVI/PS体系中引发了ZVI衍生的Fe（III）物种的还原。该反应加速了Fe（III）/Fe（II）的氧化还原循环，并在ZVI上包覆了FeSx，这两种反应都有利于HO自由基点和SO 4 −自由基点的生成。DTN-ZVI/PS在Nap和/或PS的15次降解中有11次表现出>90%的Nap去除率，是ZVI/PS的1.4-2.4倍。同样地，在五种化学类型的地下水中，Nap的去除率增加了0.47-4.3倍，在土壤中，PAHs的去除率增加了1.3-2.4倍。本研究为开发新型铁活化氧化系统修复地下水和土壤提供了技术基础。
Iron-activated persulfate (PS) systems commonly suffer from the poor Fe(III)/Fe(II) redox cycle in groundwater and soils, due to the rapid oxidation of Fe(II) by both PS-related and naturally occurring oxidative substances. Maintaining the Fe(III)/Fe(II) redox cycle is necessary to achieve the high efficiency and stability of iron-activated persulfate systems toward aromatic contaminants (e.g., PAHs) in groundwater and soils. Herein, we discover the mixtures of dithionite (DTN) and zerovalent iron (ZVI) to synergistically activate PS, and develop highly efficient, stable DTN-ZVI/PS systems for PAHs removal in groundwater and soils. DTN and intermediates sulfite/thiosulfate initiated reduction of ZVI-derived Fe(III) species in DTN-ZVI/PS systems. This reaction accelerated the Fe(III)/Fe(II) redox cycle and coated ZVI with FeSx, both favoring the generation of HOradical dotand SO4−radical dot. DTN-ZVI/PS exhibited Nap removal of >90% in water during 11 of 15 supplementations of Nap and/or PS, 1.4–2.4 times ZVI/PS. Similarly, 0.47–4.3 fold increments of Nap removalkobswere obtained in five chemical types of groundwater, and 1.3–2.4 fold increments of PAHs removal in soils. This study may provide a technical basis to develop new Fe-activated oxidation systems for groundwater and soil remediation.