Design and fabrication of a simple and cost-effective microalgae culture
photobioreactor and optimization of culture conditions
Abstract
In connection with the cultivation of microalgae, the type of
photobioreactors is one of the major parameters that should be
considered as it directly affects the economy and efficiency of the
process. In this study, a new design and fabrication of a microalgae
culture photobioreactor using a plastic bag were performed. The
performance of the photobioreactor was enhanced, and technically
evaluated through tests such as stability, physical strength, light
penetration rate, mass transfer rate, temperature control and mixing.
The experimental results on plastic photobioreactors indicated that the
main issues were related to the aeration and mixing in the system. To
address this problem, an airlift pump was designed and installed at the
end of the photobioreactor. The performance of the photobioreactor in
the production of microalgae biomass was tested using the municipal
effluent of Malek Ashtar University as a culture medium and inoculation
of Chlorella vulgaris species. To optimize the culture conditions
of microalgae, three factors: urea, phosphate, and baking soda
concentrations were considered. The results showed the relationship
between carbon, nitrogen, and phosphorus sources in increasing the
cellular content of microalgae, which in the minimum amount of organic
carbon source, with increasing the concentration of nitrogen and
phosphorus, cell biomass production increases significantly.
Accordingly, the production of more than 14 g/l of biomass in the amount
of 0.9 g/l of baking soda, 0.25 g/l of urea, and 0.5 g/l of phosphate
was obtained..