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

•Refined oil extraction units produce a highly pollutant effluent difficult to threat.•AOPs alone and combined were evaluated to reduce the oil extraction effluent impact.•Fenton’s process was the most efficient of AOPs used alone to threat the effluent.•Combination of Fenton’s and Ozone reaction achieve the best COD removal.•Fenton and ozone (pH 9) achieve the best phenolic content and toxicity reduction.