About 400 trillion liters of wastewater is generated yearly due to widespread and inefficient water use. The wastewater from different sources contains many nutrients, including nitrogen, phosphorous, and carbon. Therefore, these nutrients must be recovered using appropriate sustainable processes. The selection of the proper process depends upon the type of waste and its generation. Hence, there is a need to implement a biorefinery approach to utilize organic and biological pollutants to recover energy and bioproducts. For sustainable and inexpensive wastewater treatment, microalgae-based processes have garnered considerable interest. The biomass produced by microalgae can be used in bioenergy production and other value-added products. Thus, this chapter provides state-of-the art information regarding the potential of biomass-based integrated biorefineries for effluent treatment.