Enhanced Degradation of Bisphenol Af (Bpaf) by Visible Light Irradiated Zero Valent Iron Activated Persulfate System

Abstract

In this study, we conducted a systematic study of bisphenol AF (BPAF) removal by visible light coupled zero valent iron activated persulfate (Vis/Fe0/PS) system. The results showed that the use of visible light significantly improved the removal efficiency of BPAF in Fe0/PS system. Under visible light irradiation, PS became excited, which favored its reaction with Fe2+ and the formation of hydrogen peroxide to produce more free radicals. Moreover, Fe3+ could form complex with mono-hydroxylated and mono-carboxylated intermediate of BPAF, and the photoinduced ligand-metal charge transfer (LMCT) process can effectively transfer the charge to the metal ion, accelerating the reduction of Fe3+ to Fe2+ to enhance the generation of free radicals. The generation of hydroxylation products of bisphenol AF in the Vis/Fe0/PS system is greatly increased compared to the Fe0/PS system. The Vis/Fe0/PS system demonstrated great application value that it reduced the economic cost of BPAF treatment, and sunlight irradiation was also effective in outdoor degradation test.  Findings of this study provides new insights into the synergistic role of visible light in Fe0/PS systems and may advance the practical application of Vis/Fe0/PS system in water and wastewater treatment.

Keywords: Bisphenol AF, Visible light/zero valent iron/persulfate, Synergistic effect, Reaction mechanism, Real application