Degradation of sulfamethoxazole by the heterogeneous Fenton-like reaction between gallic acid and ferrihydrite

) together with the adsorbed and aqueous Fe(II). At pH 4.0, this Fenton-like reaction could lead to SMX degradation at a rate of 38.2% and 65.6% when GA concentration were set at 0.1 and 0.2 mM, respectively. Elevating pH inhibited SMX degradation process. Citric acid had no effect on SMX degradation, while ascorbic acid showed a promotive effect. Moreover, HPLC-MS showed the presence of 12 intermediate products, and the proposed pathways for SMX degradation included cleavage, demethylation, oxidation and electrophilic substitution. This work could enhance our understanding on how the abiotic soil Fenton-like reaction controls the fate of SMX in soil environments.