Conclusion

The present study highlights the possibility of treatment of domestic wastewater with biofuel production using Euglena sp. (indigenous algae). The results indicate that culturing algae in mixotrophic mode offers an efficient removal of TOC, N and P from domestic wastewater without any pre-treatment. Developing nations in tropical region need to safeguard and sustain existing freshwater resources through technically feasible, economically viable and environmentally sound technologies to treat wastewater. Algal based wastewater treatment would be effective in tropical countries in reducing eutrophication. Euglena sp. with high biomass productivities accumulate substantial lipid in the cells while removing the nutrients from wastewater. The lipid profiles of the extracted algal oil were similar to the vegetative feedstock oils, indicating a good quality fuel for energy generation. The recycling of nutrients by converting the sewage to algal biomass and then to biofuel is a major environmental benefit to  the system. This would also help in mitigating GHG’s through assimilation of carbon (as algae are photosynthetic organisms). Algae based pond systems deployed in the rapidly growing cities would aid in the sustainable management of wastewater through low cost treatment with the prospects of biofuel in addressing the regional energy demand.