A closed solar
photobioreactor for cultivation of microalgae under supra-high irradiance:
basic design and performance
J.
Masojídek,
Š.
Papáček,
M. Sergejevová, V. Jirka, J. Červený,
J.
Kunc, J. Korečko, O. Verboviková, J. Kopecký,
D.
Štys,
G. Torzillo
Journal of Applied Phycology, 15(2):
239-248
Abstract:
An account is given of the setting up and use of a
novel type of closed tubular photobioreactor at the Academic and University
Centre in Nove Hrady, Czech Republic. This "penthouse-roof"
photobioreactor was based on solar concentrators (linear Fresnel lenses)
mounted in a climate-controlled greenhouse on top of the laboratory complex
combining features of indoor and outdoor cultivation units. The dual-purpose
system was designed for algal biomass production in temperate climate zone
under well-controlled cultivation conditions and with surplus solar energy
being used for heating service water. The system was used to study the
strategy of microalgal acclimation to supra-high solar irradiance, with
values as much as 3.5 times the ambient value, making the approach unique.
The cultivation system proved to be fully functional with sufficient mixing
and cooling, efficient oxygen stripping and light tracking. Experimental
results (measurement of the maximum photochemical yield of PSII and
non-photochemical quenching) showed that the cyanobacterium Spirulina
(= Arthrospira) platensis cultivated under sufficient
turbulence and biomass density was able to acclimate to irradiance values as
high as 7 mmol photon m-2 s-1. The optimal biomass
concentration of Spirulina cultures in September ranged between 1.2
to 2.2 g L-1, which resulted in a net productivity of about 0.5 g
L-1 d-1 corresponding to a biomass yield of 32.5 g m-2
d-1 (based on the minimum illuminated surface area of the
photobioreactor).
(Institute of Physical Biology,
University of South Bohemia, Zámek 136, Nové Hrady, CZ-37333, Czech
Republic, e-mail: masojidek@alga.cz)