Architectural Bio-Photo Reactors: Harvesting Microalgae on the Surface of Architecture - Biotechnologies and Biomimetics for Civil Engineering - page 172

Fig. 7.11 Glass block photo-biorreactor. Diagram (R. Cervera and J. Pioz)

Today, the most profitable product obtained from the microalgae is bio-fertil-
izer and agricultural bio-stimulants with almost immediate return on investment.
We must take into the consideration that the level of energy that balances chemical
fertilizers, especially nitrogen, is responsible for a large part of energy con-
sumption in agriculture. In particular, we can say that in developing countries
fertilizers account for up to 70 % of total energy consumed in agriculture and in
developed countries up to 40 %. Specifically in Spain the impact of bio-fertilizers
in agriculture is 45 %.

7.4.1 Horizontal Photo-Bioreactor for Roof and Urban
Fountains: Covered

This system is easily applicable to sources or urban landscaped ponds and trans-
forming these elements in microalgae photo bioreactors. It is an innovative
combination of cultivation of microalgae in building systems with indoor archi-
tectural function for energy and other products from biomass and microalgae and
the fixation of CO 2 and improvement of the water cycle (Fig. 7.13 ).
The system supports the cover with simple and inexpensive materials such as
plastic film. In this case it becomes semi-closed photo-bioreactor with a slight
increase in productivity.
It is a shallow pool built by waterproofing sheet and piping system for water
supply, nutrients and collecting the harvest. The contribution of CO 2 from the
atmosphere may come or be brought directly.