I am never a fan of land-based biofuels because they are worse for the environment than fossil fuels, and I regard algae fuels as problematic due to the difficulty of separating phytoplankton from water. However,
this use of algae as a means to treat sewage as well as serve as biofuel is noteworthy because it also serves to remediate an environmental liability. I proposed this in an article I published five years ago where
I question the use a switchgrass as a sustainable biofuel. I suggested the integration of biofuel algae with sewage treatment plants to supply nutrients and cement factories or power plants to supply carbon dioxide. The current set-up gets carbon dioxide from the air, but one of my lab activities shows that
algae growth is boosted by the addition of carbon dioxide to the water. Even though the author points out that costs are lowered by the use of common strains of algae, it is not clear whether or not the project is cost-effective. I would think that the integration of a carbon emitting source can only serve to enhance the
economic sustainability of algae biofuels.