Evaluation of three microalgae within an integrated friendly climatic change bioprocess for real two-phase decanter extraction process olive mill wastewater bioremediation

Abstract

A new bioprocess for the bioremediation of olive mill wastewater from two-phase extraction process was designed with the following operation units, flocculation-sedimentation, photolysis by artificial ultraviolet light and microalgal culture in which Chlorella vulgaris, Neochloris oleoabundans and Scenedesmus quadricauda were evaluated. The main innovation of this work is the use of microalgae as a third step for the treatment of OMWW and at the same time the production of proteins, lipids, carbohydrates, pigments, and genetic materials which can be exploited in the production of new compounds. In fact, the experimental results of flocculation-sedimentation and artificial photolysis show that the removal percentages in terms of chemical oxygen demand, and total phenolic compounds were 53.3 %, and 35.5 %, respectively. The biochemical composition of the harvest N. oleoabundans biomass determined 8.83 ± 0.133 % (w/w) proteins, 56.4 ± 1.02 % (w/w) carbohydrates, 27.4 ± 0.270 % (w/w) total lipids, and 0.521 ± 0.156 % (w/w) total pigments. The final treated water quality allows its use in agriculture for irrigation/fertirrigation. The final atmospheric-CO2 removal yields were 0.446, 0.303, and 3.23 g of CO2/g of generated biomass for C. vulgaris, N. oleoabundans, and S. quadricauda, respectively.