Solar technology‒closed loop synergy facilitates low-carbon circular bioeconomy in microalgal wastewater treatment

Abstract

Abstract The circular bioeconomy framework addresses the global transition toward resource-efficient and low-carbon economies. The use of microalgae in sustainable circular bioeconomy largely suffers from energy consumption and underutilization of residual biomass, leading to greenhouse gas (GHG) emissions. This analysis-based perspective reveals that closed loop microalgal wastewater systems reduce GHG emissions by >50% and enhance valorization of residual biomass for value-added products compared to open loop approach. Integrating solar technologies in closed loop system further reduces GHG emissions by 99% and aligns with 11 UN sustainable development goals, making it a suitable model for a zero-waste and low-carbon circular bioeconomy.