CULTIVATION OF SCENEDESMUS OBLIQUUS IN MIXTURES OF URBAN AND OLIVE-OIL MILL WASTEWATERS FOR THE DUAL APPLICATION OF ALGAL BIOMASS PRODUCTION AND WASTEWATER TREATMENT

Olive-oil mill wastewater (OMW) is a great environmental problem because of its high organic load plus another antioxidant compounds as phenolic compounds. On the other hand, the treated urban wastewater (TUW) in depuration plants, which have primary and secondary treatment processes, is directly disposed to public waterways. Both wastewaters could be used as sources for microalgal culture media constitution. These wastewaters are rich in nitrogen and phosphorus compounds such as ammonium, nitrates and phosphates as well as organic and inorganic compounds. The revalorization of these wastewaters throughout the microalgal biomass production and the reutilization of the final treated water were studied. The crude OMW was pretreated by flocculation and ultraviolet light before microalgal culture. All microalgal experiments were done in batchphoto-bioreactors (1 L work capacity) at laboratory scale. The operational conditions were agitation rate = 200 rpm, T = 25 degrees C, aeration rate = 0.5 Llmin and continuous light with illumination intensity equal to 359 mu E m(-2) s(-1). Results revealed that the new proposed process lead to improve the final water quality. High removal percentages of organic matter and nitrogen species were registered. The final biomass obtained was characterized by high energetic compounds percentages (carbohydrate and lipid contents).