The growing populationSewage sludge has resulted in a substantial burden on water supplies and a corresponding increase in wastewater generation. Consequently, releasing untreated wastewater into receiving bodies of water has deleterious consequences. The efficient wastewater treatment in this situation requires ongoing effort. Owing to its increased treatment efficiency, the algae-based treatment system has gained attention lately. Algae cultivation in wastewater is an environmentally friendly remediation method that can replace traditional technologies. The reason behind this is its capacity to photosynthesize and its rapid growth in low-cost nutrient source of wastewater. Algae in wastewater lowers both the organic loadsOrganic load and the inorganic nutrients. Unlike traditional treatment methods that generate hazardous sludge, algae-mediated treatment methods yield nutrient-loaded biomass that can be utilized for the manufacture of value-added products such as biofuels and fertilizers. Nevertheless, this approach has some significant drawbacks because the biological method needs a lot of land and more time to operate. This chapter outlines the benefits and drawbacks of the various biological wastewater treatment techniques as well as their many applications along with prospects.