Enhanced peroxymonosulfate activation for effective norfloxacin degradation by sepiolite-based FeCo layered double hydroxide composite

In this study, the FeCo layered double hydroxide/Sepiolite composite was successfully synthesized by a water bath approach which exhibited outstanding norfloxacin (NOR) degradation performance in presence of peroxymonosulfate (PMS). The reaction rate constant in the FeCo-LDH/Sepiolite/PMS system was 0.1644 min−1, which was around 1.78 times greater than that in the FeCo-LDH/PMS system. The introduction of the sepiolite carrier, which led to an increase in specific surface area and pore volume, was principally responsible for the considerable improvement in PMS activation efficiency. Moreover, the composite presented good stability and reusability. According to the results of the electron paramagnetic resonance (EPR) and quenching tests, the predominant reactive species in the FeCo-LDH/Sepiolite/PMS/NOR system were SO4•- and 1O2. Furthermore, possible NOR degradation pathways and catalytic mechanism were proposed. In summary, our research provised new ideas in the synthesis of promising mineral based PMS catalyst for wastewater treatment.