WS2 significantly enhances the degradation of sulfachloropyridazine by Fe(III)/persulfate

The use of antibiotics has become an indispensable part of the production and life of human society. Among them, sulfonamide antibiotics widely used in humans and animals are considered to be one of the most crucial antibiotics. However, antibiotics are difficult to degrade naturally, leading to an accumulation in the environment and a potential hazard to human health. In this paper, WS2 as a co-catalyst could reduce trace Fe(III) to Fe(II) which exhibited a great activating ability to PS through the exposed W(IV) active sites, and formed the Fe(III)/Fe(II) cycle to degrade sulfachloropyridazine (SCP) continuously. This paper systematically discussed the degradation of SCP under different conditions in the PS/WS2/Fe(III) system, including the amount of WS2, Fe(III) concentration, PS concentration, initial pH, natural organic matter (NOM) and common anions (NO3-, Cl-, HCO3-, HPO42- and H2PO4-). The experimental results showed that PS/WS2/Fe(III) system possessed a strong degradation ability for SCP in a wide pH range. NO3- and Cl- could promote the degradation of SCP a little. HCO3-, HPO42- and H2PO4- could significantly inhibit the degradation of SCP. The main types of free radicals that degraded SCP were explored. In addition, the stability and reusability of WS2 were examined, and two possible degradation pathways of SCP were proposed.