Hydroxylamine hydrochloride enhanced Fe-C nano-microelectrolytic material for efficient peracetic acid activation: Proton/electron synergistic effect

Abstract

pH and reduction of Fe(III) are the limiting factors of iron-induced advanced oxidation processes. In this study, hydroxylamine hydrochloride (HAH) was employed as a proton (H⁺) and electron donor to adjust pH for ions leaching and reduce Fe(III) to further promote efficiency and reactive species generation in Fe-C nano-microelectrolytic material (nMET)/peracetic acid (PAA) system. It was demonstrated that HAH remarkably boosted Fe(II) recycle and continuous supplied H⁺ to produce organic radicals and hydroxyl radicals in the nMET/HAH/PAA system, based on the consequences of H⁺ and Fe conversion analysis, electrochemical experiment, electron para-magnetic resonance spectrometer analysis and quenching test. After the addition of HAH, the degradation efficiency of the nMET/PAA system for metronidazole (MNZ) increased from 31.6 % to 84.7 %. nMET/HAH/PAA system showed ideal tolerance to wide pH (3.0−9.0), Cl⁻, NO₃⁻ and SO₄²⁻, while H₂PO₄⁻ inhibited the MNZ degradation. Further, MNZ was transformed into low toxic products through processes of N-denitration, nitro-reduction and ring-opening in the nMET/HAH/PAA process. This research proposed an insight into the role of HAH in the Fe-based advanced oxidation processes for emerging contaminants remediation.