A photobioreactor is a bioreactor which incorporates some type of light source. Virtually any translucent container could be called a photobioreactor, however the term is more commonly used to define a closed system, as opposed to an open tank or pond. Because these systems are closed, all essential nutrients must be introduced into the system to allow algae to grow and be cultivated. A pond covered with a greenhouse could be considered a photobioreactor. A photobioreactor can be operated in "batch mode" but it is also possible to introduce a continuous stream of sterilized water containing nutrients, air, and carbon dioxide.Algae can also be grown in a photobioreactor. As the algae grows, excess culture overflows and is harvested. If sufficient care is not taken, continuous bioreactors often collapse very quickly, however once they are successfully started, they can continue operating for long periods. The photobioreactor is designed to provide optimal illumination, mixing, CO2 mass transfer, and nutrients to the phototrophic liquid suspension.
Types of photobioreactor -
http://www.instructables.com/id/Simple-Algae-Home-CO2-Scrubber-Part-1/ – some easy home made and lab made photobioreactor designs are there in this web site..