Biotreatment of olive washing wastewater by a selected microalgal-bacterial consortium

Abstract

This purpose of the study was the development of a microalgal-bacterial consortium to degrade phenolic compounds. Two microalgae were isolated and characterized from an olive wash water (OWW) storage basin and identified as Scenedesmus obliquus and Chlorella vulgaris according to their 18S rRNA gene sequences. The two strains were cultured in synthetic olive washing water medium containing phenolic compounds, which showed they were capable of growth in the presence of these substances, although they were sensitive to phenolic compounds and their growth decreased compared to controls grown in the absence of the compounds. Complementary experiments were carried out using a microalgal-bacterial consortium containing the two microalgae and two bacterial strains able to degrade phenolic compounds (Raoultella terrigena and Pantoea agglomerans). The results showed that the microalgal-bacterial consortium actively metabolized phenolic compounds with more that 99% of phenolic compounds removed at 48 h. The consortium also removed significant amounts of N and P from the liquid medium. The selected microalgal-bacterial consortium appeared to be a promising candidate for the bioremediation of OWW.