Abstract The olive mill wastewater (OMW) is a stable emulsion composed by water, olive pulp and residual oil. An approach for using this waste as a renewable resource is of greater interest. Several authors have been studding physicochemical treatment methods. However, the biological treatments allow not only the treatment, but also the effluent valorization, by producing several valuable products. This effluent is also a source of natural antioxidants and its extraction is economically attractive. The ideal OMW valorization process could be achieved by the combination of methods, for instance the use of physical-chemical methods as pretreatment can highly reduce the pollutants concentrations and allows better production efficiency by microorganisms.