Heterogeneous photo-Fenton-like degradation of emerging pharmaceutical contaminants in wastewater using Cu-doped MgO nanoparticles

Abstract

A facile thermal decomposition method was utilized to synthesize mesoporous Cu-doped MgO nanoparticles. These Cu-MgO nanoparticles were shown to be efficient photo-Fenton-like catalysts for degrading emerging pharmaceutical contaminants in wastewater and completely oxidized salicylic acid within 1 h under optimized conditions. Tetracycline was shown to be converted to other intermediates with a large portion of it undergoing full mineralization. Batch experiments were conducted to demonstrate the effects of Cu loading on MgO, overall catalyst loading, and H2O2 concentration on the salicylic acid and tetracycline conversion and rate constants. Quenching experiments revealed that both •OH radicals or HO2•/•O2- radicals were involved in the reaction, with the latter showing a higher contribution. The surface dissolution of MgO was shown to increase solution pH which completely prevented Cu from leaching out while retaining high activity. The catalyst reusability was shown to be satisfactory with high activity and conversion being preserved over five cycles.