Microwave-enhanced Fenton-like system, Cu(II)/H₂O₂, for olive mill wastewater treatment

Abstract

Olive mill wastewater (OMW) is a substantial pollutant not only because of its high organic matter content and recalcitrant compounds such as polyphenols, but also due to its high chemical oxygen demand and biological oxygen demand. Its degradation by means of hydroxyl radicals generated from microwave application in the presence of hydrogen peroxide and Cu(II) has been investigated. The optimal experimental conditions were found to be a microwave intensity of 680 W, the presence of Cu(II) and relatively concentrated hydrogen peroxide (12 mol L⁻¹). In these conditions, discolouration of OMW reached 98.0±0.2% and phenolic compounds decreased to 81.8±0.2% of their initial concentration after 12 min microwave time. Fourier transform infrared analysis confirmed that microwave degradation of phenols by means of the Fenton-like system Cu(II)/H₂O₂ could be an efficient solution for the treatment of olive mill wastewater.

Keywords:

• Fenton-like
• microwave
• olive mill wastewater
• polyphenols