Effective degradation of sulfamethoxazole with Fe2+-zeolite/peracetic acid

Peracetic acid (PAA), a green disinfectant, has been widely used in the wastewater treatment. Here, a novel heterogeneous advanced oxidation process (Fe 2+ -zeolite/PAA) capable of generating hydroxyl radical was developed to remove sulfamethoxazole (SMX) from the contaminated water. The influences of various operational parameters including the initial pH, dosages of PAA and Fe 2+ -zeolite and water matrix on the removal of SMX were investigated. The complete removal of SMX occurred at mild pH condition (around 7.0) within 50 min. With the increase in PAA concentration or Fe 2+ -zeolite dosage, the degradation of SMX both enhanced. Presence of metal cations, inorganic anions and natural organic matter in the reaction system had a different degree of influence on SMX degradation. Based on the radical scavenging experiment, hydroxyl radical was proved to be mainly responsible for SMX oxidation. The degradation mechanism of SMX by Fe 2+ -zeolite/PAA was tentatively proposed showing three different reaction pathways including hydroxylation, nitrosation and bond cleavage according to the detected transformation products.