Degradation of Rhodamine B at neutral pH using modified sponge iron as a heterogeneous electro‐Fenton catalyst

Abstract

Sponge iron was used as heterogeneous electro‐Fenton (EF) catalyst. Then, the catalytic activity and durability of sponge iron was greatly improved after modified by polytetrafluoroethylene (PTFE). Scanning electron microscopy, energy dispersive X‐ray, X‐ray diffraction spectrometry, and vibrating sample magnetometer were carried out to further understand the surface morphology, element composition, substance composition, and magnetic property, respectively. The PTFE modified sponge iron exhibited excellent mineralization performance for treatment of 20 mg/L Rhodamine B solution under the optimized conditions (catalyst dosage 0.5 g/L, current density 50 A/m2), achieving almost complete decolorization, 90.13% total organic carbon removal, and 93.24% Chemical Oxygen Demand removal after 120 min electrolysis. Moreover, the results confirmed that the modified sponge iron showed satisfactory durability after five times consecutive cycles, and could be a promising heterogeneous EF catalyst. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 989–995, 2018