Photobioreactors as potential tools for environmentally friendly and sustainable buildings

Abstract

Global warming is a critical risk for the balance of nature, and its effects are increasing due to gases like CO2. One approach for CO2 capture is bringing together microalgae and buildings in esthetic bio-facade systems for obtaining environmentally friendly benefits. The aim of this study is to investigate the microalgae photobioreactors (PBR) as a potential bio-facade unit. Bio-facade concept focused on the multiple uses of water and nutrients, as well as CO2 capture, to highlight the sustainability and practicality. Chlorella vulgaris is selected as a model microalga due to its low doubling time and high biomass productivity. Experiments covered the dilutions of microalga medium (10%, 20%, 40%, 80%), recycling the cell separated medium and addition of CO2-enriched air (5% and 10%) focusing on their effects on various key factors like biomass and photosynthetic activity. PBR integrated laboratory scale house unit has also been constructed lastly. According to the preliminary results, up to 80% dilution, up to three cycles of medium and 5% CO2-enriched environment provided the high level of activity for bio-facade system. Interior air quality, changing of temperature and amounts of CO2–O2 with increasing of the biomass were investigated in PBR integrated laboratory scale house unit which depended on the outcomes of preliminary experiments (20% dilution and 5% CO2-enriched air). The results of unit showed the positive effects of the microalga integration with regards to its capability as a biofilter and a biocurtain for the sustainability.