Chen, ZehongXia, PanWang, DazhiNiu, XiaodongAo, LixinHe, QiangWang, ShaYe, ZhihongSirés Sadornil, Ignacio2023-06-162025-04-192023-04-190048-9697https://hdl.handle.net/2445/199403Hydroxyl radical (¿OH) is considered the dominant reactive species in the electro-Fenton (EF) and Fered-Fenton (EFFere) processes for wastewater treatment. However, in chloride-rich media, this is arguable due to the obscure mechanisms for the oxidant speciation and pollutant degradation. Herein, the role of active chlorine and Fe(IV)-oxo species (FeIVO2+) as primary oxidizing agents in HClO-mediated Fered-Fenton (EF-Fere-HClO) process is discussed, along with the dependence of their contribution on the pollutant structure. HClO generated from anodic oxidation of Cl− can be consumed by added H2O2 to form singlet oxygen (1O2), which is detrimental because this species is quickly deactivated by water. The reaction between HClO and Fe2+ was proved to generate FeIVO2+, rather than ¿OH or Cl¿ suggested in the literature. The yield of FeIVO2+ species was proportional to the Cl− concentration and barely affected by solution pH. The long-lived HClO and FeIVO2+ can selectively react with electron-rich compounds, which occurs simultaneously to the non-selective attack of ¿OH formed from Fenton's reaction. The FeIVO2+ and ¿OH concentration profiles were successfully modelled. Although the accumulation of toxic chlorinated by-products from HClO-mediated oxidation might cause newenvironmental concerns, the toxicity of pesticide wastewater with 508mMCl− was halved upon EF-Fere-HClO treatment.application/pdfengcc-by-nc-nd (c) Elsevier B.V., 2023https://creativecommons.org/licenses/by-nc-nd/4.0/ClorursElectroquímicaContaminantsChloridesElectrochemistryPollutantsinfo:eu-repo/semantics/article7334952023-06-16info:eu-repo/semantics/openAccess