Abstract: In flotation wastewater, the residual organic reagents usually coexist with various ions, which can promote or inhibit the ozonation of organic reagents. The effects of coexisting ions on remo FRF-MP-2021val efficiencies of aniline aerofloat (AAF) and its mineralization by the ozonation were investigated. The results indicated that the inhibition order of coexisting anions for the ozonation of AAF was as follows: CO₃^2- > S^2- > HCO₃^- > PO₄^3-. These four anions could also reduce the mineralization rate of AAF, but Cl^- and SO₄^2- had no obvious inhibitory effect. The enhancement order of coexisting metallic cations for the ozonation of AAF was as follows: Fe³⁺>Cu²⁺ > Pb²⁺ > Ca²⁺≈Mg²⁺ > Zn²⁺. All of metallic cations could increase the mineralization rate of AAF, which showed the catalytic ozonation capacity of metallic cations. Among them, Fe³⁺ achieved the highest catalytic capacity. The kinds of organic byproducts in the Fe³⁺/O₃ were much less than that in sole O₃ after 60 min degradation of AAF. The results indicated that the catalytic ozonation capacity of Fe³⁺ could enhance further oxidation of byproducts, leading to more complete degradation of AAF collector.