Microalgae biofilm carbon and nitrogen sequestration as a tool for economic and environmental sustainability

Abstract The continuous release of greenhouse gases (GHG) is negatively affecting the sustainability of the ocean as a carbon sink via acidification and ocean warming. The capture and storage of GHGs is important to reduce the long-term effects of the emissions. The use of microalgae biofilms for GHG sequestration is a promising method due to their ability to adapt to different environmental conditions and their rapid growth characteristics. The current review shows how the process of microalgae biofilm sequestration of carbon and nitrogen contributes to economic and environmental sustainability. The review shows that the use of wastewater as a medium for the cultivation of microalgae biofilm is cost effective and will increase the economic feasibility of the use of microalgae biofilm for GHG sequestration, but the dynamic nature of microalgae biofilm structure, which is directly influenced by the type of substrate, liquid flow, and environmental conditions, is a limitation. The results of the current review cannot assure that the use of microalgae biofilm is highly economically viable using techno-economic analysis due to the lack of accessible data showing the precise estimation operating expenditures and capital expenditures. The current review also shows that the use of microalgae biofilm for GHG capture will lead to environmental sustainability because the increase in availability of bioresources caused by microalgae biofilm cultivation will lead to a decrease in the world’s economic dependency on fossil resources. Graphical abstract