Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Applied & Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan, 430079, PR China.
Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Applied & Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan, 430079, PR China.
Chemosphere. 2020 Apr;244:125568. doi: 10.1016/j.chemosphere.2019.125568. Epub 2019 Dec 10.
Persulfate (PS) is widely used for environmental remediation, but its organic contaminant removal performance strongly depends on its activation. In this study, we demonstrate that pyrite (FeS) can more effectively activate PS than the commonly used FeSO for atrazine degradation. When 3.0 mM of PS and 4.2 mM of iron salts were used, the atrazine degradation efficiency of FeS/PS was 1.4 times that of FeSO/PS, while the amount of consumed PS in case of FeS was only 53% of that by FeSO. The better PS activation performance of FeS could be attributed to its slow and sustainable release of dissolved Fe(II), inhibiting the quenching reaction between •SO/•OH and Fe(II) ions, and thus producing more reactive oxygen species for the atrazine degradation. More importantly, the surface bound Fe(II) of FeS could activate molecular oxygen to generate superoxide radical (•O), which could further promote the effective decomposition of PS by accelerating the Fe(III)/Fe(II) redox cycle. This study unravels the roles of dissolved Fe(II) and surface bound Fe(II) on the persulfate activation, and provides a promising heterogeneous persulfate activator for pollutant control and environmental remediation.
过硫酸盐（PS）被广泛应用于环境修复，但它对有机污染物的去除性能强烈依赖于其活化。在本研究中，我们证明了黄铁矿（FeS）比常用的硫酸亚铁（FeSO）更能有效地活化 PS 以降解莠去津。当使用 3.0mM 的 PS 和 4.2mM 的铁盐时，FeS/PS 对莠去津的降解效率是 FeSO/PS 的 1.4 倍，而 FeS 消耗的 PS 量仅为 FeSO 的 53%。FeS 具有更好的 PS 活化性能，这可归因于其缓慢且持续释放溶解态的 Fe(II)，抑制了 •SO/•OH 和 Fe(II)离子之间的猝灭反应，从而产生更多的活性氧物种以降解莠去津。更重要的是，FeS 的表面结合态 Fe(II)可激活分子氧生成超氧自由基（•O），这可通过加速 Fe(III)/Fe(II)氧化还原循环进一步促进 PS 的有效分解。本研究揭示了溶解态 Fe(II)和表面结合态 Fe(II)在过硫酸盐活化中的作用，并为污染物控制和环境修复提供了一种有前景的非均相过硫酸盐活化剂。
