Heterogeneous Photo-Fenton Removal of Methyl Orange Using the Sludge Generated in Dyeing Wastewater as Catalysts

Abstract

The disposal process of iron-containing sludge often leads to secondary pollution. Pyrolysis of sludge appears to be less polluting than conventional methods. Herein, the heterogeneous photo-Fenton catalysts were prepared using sludge generated in the dyeing wastewater through a simple one-step pyrolysis route. The catalysts were characterized by XRD, FT-IR, XPS, EDS, BET, and SEM. The batch experiments for methyl orange (MO) degradation were performed to evaluate the efficiency and stability of the catalysts. Among the catalysts prepared, FeCN-300 exhibited the best degradation efficiency with 92% removal of the pollutant and good stability, with approximately 90% removal of the pollutant after five cycles. The •OH was identified as the dominant reactive species. This work provides a reasonable resource utilization of iron-containing sludge.