Coupled removal of Rhodamine B and Cu2+ by activating persulfate using micron zero-valent iron

Abstract

Abstract In this study, micron zero-valent iron (ZVI) was used to activate persulfate (PS) for the coupled removal of Rhodamine B (RhB) and Cu2+. It was observed that the removal of RhB could be significantly enhanced with Cu2+ compared with that of the case without Cu2+. In addition, the reaction reduced the RhB by 96% within 10 min, and meanwhile reduced the Cu2+ by 60% within 120 min. Investigation of the mechanism revealed that, on the one hand, Cu2+ species could be turned into Cu0 and Cu+ species; on the other hand, PS and Cu2+ could first accelerate the corrosion of ZVI to release Fe2+. Then, in situ generated Cu+ and Fe2+ further decomposed PS to produce ·SO4− and ·OH, which could take part in the removal of RhB. In addition, the ZVI/PS/Cu2+ system also showed a wider pH working range than the ZVI/PS system. Our study proved that simultaneous removal of heavy metal and organic compound in the ZVI/PS/Cu2+ system was feasible.