the gaseous and aquatic phases. The algae reactor comprises of a tall and narrow greenhouse frame, while the algae growth is on sub-vertical fixed beds medium. Algal nourishment is done by thin-film circulation of the aquatic effluent and the greenhouse atmosphere is enriched by flue gases. Excess algal biomass is continuously harvested via an automated harvester, which crops the algae and accumulates it. The excess algal product may be utilized for several economic purposes starting with animal feedstock, through organic fertilizer and also as industrial raw material, in particular bio-fuels and the bio-plastics industry.