Evaluation of the Potential of Microalgae as Bioremediation Agents for Olive Mill Wastewater

Abstract

The potential for bioremediation of olive mill wastewaters with different origins—olive washing (OWW) and olive oil extraction (OMW)—among four species of microalgae (Chlorella vulgaris, Auxenochlorella protothecoides, Scenedesmus obliquus, and Arthrospira maxima) was evaluated. All microalgae could grow in the wastewaters, but C. vulgaris and C. protothecoides showed the best performances. The highest biomass productivities of 165.8 mg L−1 day−1 for OMW and 107.9 mg L−1 day−1 for OWW were achieved with C. vulgaris and A. protothecoides, respectively. Moreover, with both species, COD and nitrate contents of the two wastewaters were reduced by 60 and more than 50%, respectively. However, significant removal of polyphenols was verified only in OWW (~45%). Overall, these findings demonstrate the potential of C. vulgaris and A. protothecoides species to be used in a biological olive mill wastewater treatment process.

Keywords

• microalgae
• bioremediation
• biomass
• olive mill wastewater