Phycoremediation of Nutrients and Valorisation of Microalgal Biomass: An Economic Perspective

Abstract

Microalgae are considered as one of the most suitable feedstocks for the production of bioenergy and other valuable bioproducts for realising the dream of bio-economy. For any significant displacement of fossil-based products currently in use, cultivation of microalgae at industrial scale will be required. Industrial-scale cultivation of microalgae besides being costly would also compete with terrestrial crops for nutrients and moisture. However, several recent studies have shown the potential of culturing microalgae in municipal/industrial wastewaters. Vast quantum of agricultural nutrient ends up in the sewer which can be utilised efficiently as culturing media for algae and as a cheap and environmentally benign source of nutrients. Coupling wastewater treatment and microalgae cultivation combines the prospects of nutrient remediation and biomass production. Uncompetitive economics remain the single most significant hurdle for large-scale production and commercialisation of algal products. Coupling wastewater treatment and biomass production leads to economic savings regarding avoidance of costly wastewater treatment approaches and produces high-value algal biomass. Considering the current and projected demand for algae-based products, careful and strategic valorisation of algal biomass depending on the composition of biomass and processing strategies is critical. In this work, we have analysed the economic dimensions of coupling wastewater treatment and production of algal biomass and their subsequent valorisation to value-added products.