Boron boosted Fe3O4 activated peracetic acid for removing sulfamethazine: Role of boron and mechanism

Nowadays, antibiotic pollution is increasingly serious and posing a huge threat to ecology and human health. Therefore, it is vital to find effective approaches to remove antibiotics. In this study, boron (B) was adopted to accelerate the surface and solution Fe2+ recycle in Fe3O4/peracetic acid (PAA) system, which showed excellent performance for antibiotics removal. According the XPS analysis and experiments detection, both recycle of surface and solution Fe2+ could be enhanced in the presence of boron in Fe3O4/PAA system. 74.0% sulfamethazine (SMT) could be removed within 60 min in Fe3O4/PAA system while 93.4% could be removed within only 20 min in B/Fe3O4/PAA system and the value of k in B/Fe3O4/PAA system (0.136 min−1) was also much higher than that in Fe3O4/PAA system (0.028 min−1). The effect of boron, Fe3O4, PAA dosage and initial pH on removing SMT in Fe3O4/PAA system were also conducted. Quenching experiments and EPR experiments demonstrated that ·OH, organic radicals (R-O·) and Fe(IV) exhibited 63.1%, 17.3%, and 16.2% role in removing SMT, respectively. Possible SMT degradation pathway and the toxicity of transformation products were analyzed. B/Fe3O4/PAA exhibited superior resistance to inorganic ions and nature organic matters, good recycle ability, excellent adaptability to various pollutants, and efficient performance for antibiotics removal in natural fresh water.