Advanced oxidation processes at ambient conditions for olive oil extraction industry wastewater degradation

Abstract

The olive mills are theoretically waste free plants, at the refined oil extraction units, a highly pollutant effluent is generated. In this work the performance of different AOPs in the same multiphase reactor was evaluated to minimize real oil extraction effluent environmental impact. In terms of COD removal, the combination of Fenton and Ozone reaction simultaneously, allows the highest reduction (58.5%) although the combination of Fenton followed by ozone at pH3 lead to a similar removal, about 54%. In what regards mineralization, Fenton peroxidation alone was the most efficient process leading to 53% of TOC removal. Fentońs process presents an interesting role in the effluent treatment. However, if one bears in mind phenolic content removal and toxicity abatement, the best results were obtained by Fenton peroxidation (pH 3) followed by ozonation (pH 9). The treatment processes selection should consider the target results as well as a suitable economic analysis.