| dc.description.abstract | Microalgae cultivation using waste streams as nutrient source in industrial scale is an
unconventional, and so far untapped, process pathway to produce microalgae biomass. The main
advantage of this approach is the fact no resources are spent on nutrients, which make up for the
major part of the conventional production costs. The main limitation is that culture medium is directly
influenced by the available in-site waste streams, which limits the application of this to industrial
processes with nutrient-rich and toxin free waste streams. There is also a degree of limitation with
respect to specific nutrient concentration towards cultivation optimization. Optimization of biomass
productivity implies knowledge about the behavior of each specific microalgae strain towards
process parameters such as illumination, temperature, oxygen gas concentration in the culture
medium, nutrient availability, pH value, hydraulic retention time, mixing and heavy metal presence.
The use of the cultivated microalgae to produce methane through anaerobic digestion also put
emphasis on the specific chemical composition of microalgae.
This study was done in partnership with Biokraft AS and it integrated in the innovation projects
in business and industry COMPLETE. The purpose of this study is to investigate the effect of the
aforementioned parameters in microalgae cultivation and find out patterns to act as general guidelines
for process optimization. It also an objective of the this work to evaluate laboratory and pilot-scale
applications of conventional and wastewater-based microalgae cultivation towards the establishment
of an industrial-scale cultivation model, whose profitability under a set of conditions will be
calculated and evaluated.
The produced work highlights that there is interest in the scientific community about the
advantages of using wastewater-based microalgae cultivation systems, especially because of their
potential as a biological wastewater treatment with reduce energetic consumption. It was also found
that the cultivation technology that best suits the specific needs of this project is an internally
illuminated photobioreactor that will keep production steady and independent from the variable solar
irradiance in Norway. Furthermore, it was found that the most cost-effective solution for harvesting
the cultivated biomass is electrocoagulation. | en |
