Cr(III)-organic complexes removal from wastewater is challenging to decompose the complexes without producing toxic Cr(VI). Herein we demonstrated that oxalated zero-valent iron (Ox-ZVI) could one-step decomplex 95.4% of Cr(III)-EDTA with 94.2% removal of total Cr and 60.5% removal of TOC without generating Cr(VI) at pH 6.0. Ox-ZVI with FeC₂O₄ shell preferred to adsorb and activate O₂ to produce more reactive species than ZVI with iron oxide shell, while the generated ¹O₂ could selectively break the Cr-O and Cr-N bond to precisely decomplex Cr(III)-EDTA without producing Cr(VI). The released Cr(III) was in-situ precipitated on the surface of ZVI in Cr(OH)₃ form. Interestingly, •OH preferred the effective degradation of the released EDTA ligand to the oxidation of the chelated Cr(III) at pH 6.0. This study offers a green and facile method for the Cr(III)-organic complexes treatment, and also sheds light on the importance of reactive species adjustment for the precise pollutant control.

从废水中去除 Cr(III)-有机络合物对于分解络合物而不产生有毒的 Cr(VI) 具有挑战性。在本文中，我们证明了草酸零价铁 (Ox-ZVI) 可以在 pH 6.0 下一步解络 95.4% 的 Cr(III)-EDTA，同时去除 94.2% 的总 Cr 和 60.5% 的 TOC 而不会产生 Cr(VI) . _{具有FeC 2} O ₄壳的Ox-ZVI比具有氧化铁壳的ZVI更倾向于吸附和活化O _{2以产生更多的活性物质，而生成的}¹ O ₂可以选择性地破坏Cr-O和Cr-N键以精确解络Cr (III)-EDTA 不产生 Cr(VI)。_{释放的 Cr(III) 在 Cr(OH) 3}中原位沉淀在 ZVI 表面形式。有趣的是，在 pH 6.0 下，•OH 更喜欢释放的 EDTA 配体的有效降解，而不是螯合的 Cr(III) 的氧化。本研究为 Cr(III)-有机络合物的处理提供了一种绿色简便的方法，同时也阐明了活性物种调节对于精确控制污染物的重要性。