**Abstract**

In the recent years, due to heavy surge in the price of petrochemical products, researchers are getting interest towards renewable bioenergy resources such as algal-based biomass. In order to meet a world energy demand, current bioeconomy challenges and to produce valuable products, intensive and integrated research on algal biorefinery is highly required. Even though several research carried out study for the conversion of algae biomass to biofuel, but none of these proved economically viable. Hence, range of value added product (biodiesel, biochar, fertilizer, etc.) must be produced subsequently from algae. The utilization of microalgae for biomass production is better than agricultural crops as microalgae do not required fresh water for its growth, it can readily grow on wastewater throughout the year. Generation of wastewater is severe concern throughout the world and discharge of wastewater without proper treatment in to water bodies causes water pollution. Microalgae bear vast potential in significantly deescalating pollutant load (nitrate, TDS, ammonium, phosphate, organic load) from wastewater. The harvested algal biomass after remediation has significance role in producing biofuels and by-products in a sustainable way. In this chapter, emphasis would be given on role of algae in wastewater treatment and its biorefinary approach for sustainable energy development.

**Keywords:** microalgae, wastewater, phycoemediation, biorefinery
