Preparation of MoS2/SiO2 composites as fixed-bed reactors for Fenton-like advanced oxidation of sulfonamides in water

Abstract

Fenton-like reaction was considered one of the most prospective advanced oxidation processes in the removal of organic pollutants. To achieve efficient degradation of sulfonamides (SAs) in water, MoS2/SiO2 composites (M@Si) were fabricated by a simple “one-pot” process and packed as fixed-bed reactors (FBR) for Fenton-like reaction. The SEM and XRD results showed the nano-sized MoS2 particles (400 – 600 nm) were attached to the SiO2 particles, confirming the successful fabrication of M@Si composites. The operation conditions for the M@Si FBR were systematically optimized, including H2O2 concentration, Fe2+ concentration, pH, bed height and flow rate, and the degradation rate of > 95% was realized for sulfisoxazole (20 mg/L) at a residence time of 15 s. M@Si Fenton FBR could enhance the Fe3+/Fe2+ cycle for producing hydroxyl radicals (·OH) and self-generate singlet oxygen (1O2) from the interaction between H2O2 and MoS2. Moreover, the M@Si FBR could be operated for over six days without the plunge of degradation efficiency. Finally, M@Si FBR was successfully applied in the degradation of SAs in pond water, demonstrating the application prospect of this reactor. This system presented a simple MoS2 based Fenton catalyst for the efficient activation of hydrogen peroxide for the removal of antibiotics in continuous flow mode.