Attached cultivation technology of microalgae for efficient biomass feedstock production

The potential of microalgae biofuel has not been realized because of low productivity and high costs associated with the current cultivation systems. In this paper, an attached cultivation method was introduced, in which microalgae cells grew on the surface of vertical artificial supporting material to form algal film. Multiple of the algal films were assembled in an array fashion to dilute solar irradiation to facilitate high photosynthetic efficiency. Results showed that a broad range of microalgae species can grow with this attached method. A biomass productivity of 50–80 g m−2 d−1 was obtained outdoors for Scenedesmus obliquus, corresponding to the photosynthetic efficiency of 5.2–8.3% (total solar radiation). This attached method also offers lots of possible advantages over traditional open ponds, such as on water saving, harvesting, contamination controlling and scale-up. The attached cultivation represents a promising technology for economically viable production of microalgae biofuels.

► Attached cultivation + light dilution boosts the biomass production of microalgae.
► An high biomass productivity of 80 g m−2 d−1 for Scenedesmus was obtained outdoors.
► Photosynthetic efficiency of 10.8–17.3% (visible light) was reached outdoors.
► Potentials of water saving, power cost-effective, contamination control and scale-up.