Efficient degradation of sulfamethazine in aqueous solution by Co@MoS2-activated peroxomonosulfate: Performance and mechanism

Abstract

Sulfamethazine (SMT), a sulfonamide antibiotic, is widely present in medical wastewater and is one kind of refractory organic pollutants that endanger the water environment. An efficient and environmentally friendly degradation method is crucial for treating antibiotic wastewater. Based on the strong activation capability of transition metal ions for peroxymonosulfate (PMS) and highly affinity of MoS₂ towards PMS, the decoration of MoS₂ with transition metal ions would be an effective activation of PMS for degradation of organic pollutants. In this work, Co@MoS₂ was synthesized by hydrothermal method and used as catalyst for the degradation of SMT with PMS. Almost 100 % of sulfamethazine (SMT) was removed within 10 min. The EPR and quenching experimental results suggested that ¹O₂ was the main active species for SMT degradation in the Co@MoS₂/PMS system. The accelerated valence cycle between Co²⁺ and Co³⁺ was the key factor to PMS activation and SMT degradation. Further, the Co@MoS₂/PMS system showed good applicability to different pollutants, excellent reusability for SMT removal. Therefore, the results demonstrated that the present study process was a promising strategy for antibiotic removal.