Hydroxylamine enhanced activation of peroxymonosulfate by Fe(III)/Cu(II) bimetallic for high-efficiency degradation of AO7

In this study, a new type of iron/copper bimetallic combined with hydroxylamine (HA) activated peroxymonosulfate (PMS) was constructed to treat organic pollutants. Selecting the azo dye acid orange 7 (AO7) as the representative of organic pollutants, the new system can achieve nearly 100% degradation of AO7 within 5 min. The Fe(III)/Cu(II)/HA/PMS system mainly generates SO 4 ·− to achieve the degradation of AO7 in acidic environment, while neutral and alkaline environments rely on · OH. The presence of hydroxylamine accelerates the cycle of Fe(III)/Fe(II) and Cu(II)/Cu(I) in the system, and enhances the degradation ability of the system for organic pollutants. The addition of trace Cu(II) (1 μM) enhances the ability of a single Fe(III)/HA/PMS system to degrade AO7 in neutral and alkaline environments without causing secondary copper pollution. The common inorganic anions Cl − and NO 3 − in water have almost no effect on the degradation of AO7 in the system. The constructed Fe(III)/Cu(II)/HA/PMS system is an efficient and clean organic pollutant wastewater treatment process, which has very promising application prospects. The effect of hydroxylamine on the activation of peroxymonosulfate in Fe(III)-Cu(II) bimetallic is reported for the first time. The Fe(III)/Cu(II)/hydroxylamine/peroxymonosulfate system can remove 100% of AO7 within 5 min. Hydroxylamine enables Fe(III), which cannot activate peroxymonosulfate, to activate peroxymonosulfate efficiently. A trace amount of Cu(II) can reduce Fe(III) to Fe(II).