Fe-Ag/GAC catalytic persulfate to degrade Acid Red 73

The present study reported a novel Fe-Ag/GAC catalyst and investigated its catalytic activity for the degradation of Acid Red 73 by persulfate. The results of characterization of Fe-Ag/GAC showed that Nano-Ag was supported uniformly on GAC with high degree of crystallinity and Fe distributed mostly in the forms of noncrystalline FeO/Fe3O4 or FeOOH. The presence of catalyst greatly enhanced the removal rate of AR 73, and it was found that 99% of decolorization efficiency and 84.1% of total organic carbon removal (TOC) of AR 73 could be obtained at the neutral pH within 60 min, respectively. The optimized experiments found that either higher temperature or higher dosage of Fe-Ag/GAC or Na2S2O8 was favored for the degradation of Acid Red 73. Lowering solution pH could improve the degradation rate of AR 73. The recycling test indicated that the catalyst was relatively stable, showing a promising application.