FeCu-coal gangue heterogeneous activation of peracetic acid for degradation of sulfamethoxazole

Abstract

A novel FeCu anchored coal gangue (FeCu-CG) composite was prepared by a two-step (acidation and subsequent chemical reduction) method and applied in catalytic activation of peracetic acid (PAA) for sulfamethoxazole (SMX) removal in water. The BET, XPS, SEM, EDS, and XRD characterization of FeCu-CG indicated that it had a porous structure with the SBET area of 36.38 m² g−1 and nano-FeCu particles were successfully loaded in the CG carrier, which provided electrons and Fe(II) for PAA decomposition through the bimetallic corrosion reaction. The hydroxyl radical (HO•) was verified to be largely responsible for SMX elimination in FeCu-CG/PAA system. More than 96.4 % of SMX was removed by FeCu-CG/PAA in 40 min at initial pH ranging from 5.0 to 9.0. Increasing FeCu-CG dosage from 0.1 to 1.0 g L−1 could enhance SMX degradation in FeCu-CG/PAA system, but higher dosage inhibited SMX removal owing to the aggregation of FeCu-CG particles. Coexisting dissolved organic matter (DOM), HCO3- and Cl- suppressed SMX degradation. The degradation pathways of SMX by FeCu-CG/PAA were proffered including hydroxylation, amino oxidation, bond cleavage and coupling reaction based on five detected degradation products.