Photo-Fenton-like degradation of antibiotics by inverse opal WO3 co-catalytic Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes: A comparative study

Abstract

Advanced oxidation processes (AOPs) such as Fenton and Fenton-like process for pollutant removal have been widely reported. However, most papers choose one of the popular oxidants (H2O2, peroxymonosulfate (PMS) or peroxydisulfate (PDS)) as the oxidant via AOPs for pollutant degradation. The purpose of this work is to compare the degradation rates of the Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes. Furthermore, to solve the problem of slow regeneration of Fe2+, the visible light irradiation and inverse opal WO3 cocatalyst were added to the Fenton/Fenton-like process. The IO WO3 co-catalytic visible light assisted Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes greatly improved the degradation efficiency of norfloxacin (NOR), reaching about 30 times, 9 times and 12 times that of the homogeneous Fenton/Fenton-like process, respectively. On average, the TOC removal rates of PMS-based, H2O2-based and PMS-based processes for the five pollutants were 71.6%, 54.0%, and 59.6% within 60 min, and the corresponding co-catalyst treatment efficiencies were 0.215 mmol/g/h, 0.162 mmol/g/h, and 0.179 mmol/g/h, respectively. 1O2 and •O2− have been proven to play a vital role in the degradation of NOR via all the three IO WO3 co-catalytic photo-Fenton-like processes. In addition, the effects of different reaction parameters on the activity of degrading norfloxacin were explored. The IO WO3 co-catalytic visible light assisted Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes for removal of different persistent organic pollutants and norfloxacin in different actual wastewater have also been studied. Nonetheless, this study proves that IO WO3 co-catalytic visible light assisted Fe2+/PMS, Fe2+/H2O2 and Fe2+/PDS processes could effectively remove antibiotics from wastewater.