Conclusion

The integration of municipal wastewater treatment with algal biofuel generation is an economically viable and attractive option for reducing nutrient load (C,N,P), GHG emissions, and meeting the decentralised energy demand. The efficiency of lipid extraction from algae was found to differ according to the species, cell disruption and associated extraction methods. The highest lipid was extracted from Euglena sp. (24.6-31%) followed by Spirogyra sp. (18.4-20%) and Phormidium sp. (6.18-11.54%). Fatty acid composition analysis showed highest C16:0 and C18:1 in Spirogyra sp. followed by Euglena sp., and Phormidium sp. showed highest C18:0, when the cells were disrupted through sonication. Thus of all the methods adopted for cell disruption sonication method showed the highest efficiency. Lipid productivities of Euglena sp. were 40 times higher than Spirogyra sp. and Phormidium sp. Higher biomass productivities of wastewater-grown algae such as Euglena sp.  (6.52 t/ha/yr) suggests algae based treatment option for removal of nutrients from wastewater as well as biofuel production for fostering the sustainable production of renewable energy.