This work aimed to develop a rotating algal biofilm (RAB) cultivation system that
can be widely adopted by microalgae producers for easy biomass harvest. Algal cells
were grown on the surface of a material rotating between nutrient-rich liquid and
CO2-rich gaseous phase. Scrapping biomass from the attached surface avoided the expensive
harvest operations such as centrifugation. Among various attachment materials, cotton
sheet resulted in best algal growth, durability, and cost effectiveness. A lab-scale
RAB system was further optimized with harvest frequency, rotation speed, and CO2 levels.
The algal biomass from the RAB system had a similar water content as that in centrifuged
biomass. An open pond raceway retrofitted with a pilot-scale RAB system resulted in
a much higher biomass productivity when compared to a control open pond. Collectively,
the research shows that the RAB system is an efficient algal culture system for easy
biomass harvest with enhanced biomass productivity.