Cultivating Microalgae in Domestic Wastewater for Biodiesel Production

Abstract

The objective of this study was to evaluate the growth of nine species of microalgae (green and blue green microalgae) on domestic waste water samples obtained from Zenein Waste Water Treatment Plant (ZWWTP), Giza governorate, Egypt. The species were cultivated in different kind of waste water; before treatment; after sterilization; with nutrients with sterilization and with nutrients without sterilization. The experiment was conducted in triplicate and cultures were incubated at 25±1°C under continuous shaking (150 rpm) and illumination (2000 Lux) for 15 days. pH, electric conductivity (EC), optical density (OD) , dry weight (DW), were done at the time of incubation and at the end of experiment, in addition to determine the percentage of lipid and biodiesel. The data revealed that, domestic waste water with nutrient media (T3) was promising for cultivation of five algal species when compared with conventional media, Moreover, domestic waste water after sterilization (T2) was selected media for cultivation of Oscillatoria sp and Phormedium sp. However, T1 media (waste water without treatment) was the promising media for cultivation of Nostoc humifusum. The biodiesel produced from algal species cultivated in waste water media ranged from 3.8 to 11.80% when compared with the conventional method (3.90 to 12.52%). The results of this study suggest that growing algae in nutrient rich media offers a new option of applying algal process in ZWWTP to mange the nutrient load for growth and valuable biodiesel feedstock production.