Peroxymonosulfate activation by sponge-based FeS material for efficient degradation of tetracycline: The critical role of sponge

Abstract

The effective control of antibiotic pollution in water has become an important issue in the field of environmental protection. In this study, the composite of iron sulfide and melamine sponge (FeS@MS) was successfully synthesized by in-situ synthesis method and applied to the oxidative removal of tetracycline (TC) in the presence of peroxymonosulfate (PMS). Under optimal conditions ([FeS@MS] = 0.1 g/L and [PMS] = 0.2 mM), 95.7% of TC was degraded in 5 min. The presence of NO3−, SO42−, and Cl− slightly inhibited TC removal, whereas HPO4− had a certain promotion effect in activating PMS to degrade TC. The primary reactive oxygen species (ROS), including SO4−, OH, 1O2, and O2− were identified through electron paramagnetic resonance (EPR) spectroscopy and radical quenching experiments. In addition, Fe3+ in solution could react with FeS to produce Fe2+, which continuously activates PMS to generate radicals for TC degradation. The presence of MS reduced the agglomeration of FeS and played a protective role in the slow release of Fe2+. The degradation performance was further validated in real water matrices. This study provided new insight into fabricating functional material for the remediation of antibiotic wastewater.