Waste stream valorization-based low-carbon bioeconomy utilizing algae as a biorefinery platform

Abstract

The increasing population growth and rapid industrialization have caused severe pollution issues caused by the uncontrolled release of flue gas and wastewater. By employing an algal-based biorefinery platform, the resource potential of these waste streams can be fully exploited and valorized to produce value-added products, achieving waste minimization, pollution mitigation, and circular economy. This review described the role of algae in simultaneous bioremediation and resource recovery from wastewater and flue gas for the biosynthesis of valuable bio-compounds. For flue gas bioremediation and valorization, topics such as algal tolerance and strain improvement, pilot-scale applications, limitations and possible solutions, techno-economic assessment, and life-cycle analysis were discussed. Subsequently, the valorization of wastewater as low-cost feedstock for the biosynthesis of valuable products, including biofuels (biogas, bioethanol and biodiesel), proteins, polyunsaturated fatty acids and pigments, were reviewed in detail with their opportunities and challenges. Chlorella sp. And Scenedesmus sp. Have been customarily employed as platform algae for co-valorizing wastewater and flue gas due to their strong adaptability. Government policies, such as carbon tax, incentives, fundings, national research programs and others, which contribute to the development of waste streams valorization-based algal bioeconomy, were also summarized and discussed.