Recyclable MFeO (M = Mn, Zn, Cu, Ni, Co) coupled micro-nano bubbles for simultaneous catalytic oxidation to remove NO and SO in flue gas.

NO can be efficiently removed by micro-nano bubbles coupling with Fe and Mn, but the catalyst cannot be reused and the adsorption wastewater should be treated. This work developed a new technology that uses micro-nano bubbles and recyclable MFeO to simultaneously remove NO and SO from flue gas, and clarified the effectiveness and reaction mechanism. MFeO (M = Mn, Zn, Cu, Ni and Co) prepared by a hydrothermal method was characterized. The results show that MFeO can be activated to produce ˙OH which can accelerate the oxidation absorption of NO . Compared with no catalyst, the NO conversion rate increased from 32.85% to 83.88% in the NO -SO-MFeO-micro-nano bubble system, while the removal rate of SO can reach 100% at room temperature. The catalytic activities of MFeO showed the following trend: CuFeO > ZnFeO > MnFeO > CoFeO > NiFeO. The results provide a new idea for the application of advanced oxidation processes in flue gas treatment.