Application of electro-Fenton oxidation for the detoxification of olive mill wastewater phenolic compounds.

Olive mill wastewaters are powerful pollutants that are difficult to treat as they contain high concentrations of recalcitrant and toxic polyphenolics of different molecular masses. We report in this paper that pre-treatment of phenolic fractions extracted from olive mill wastewaters as well as a synthetic phenolic mixture by the electro-Fenton method is a highly efficient procedure in which low mass phenolics are polymerised to polyphenolics and removed by precipitation. This decreases the toxicity load by 78% and makes the waste amenable to further anaerobic post-treatment.