The project aims to develop expertise in the cultivation of the green microalga Chlorella vulgaris in an innovative, low-cost photobioreactor using microbubble technology. Emphasis is placed on resources not used by conventional agriculture, such as brackish water and municipal wastewater. This approach increases the diversity, sustainability, and quality of aquaculture products while reducing their environmental footprint.

The following innovations are applied in combination to develop cultivation protocols for C. vulgaris that optimize growth and the production of desirable chemical constituents for use in aquaculture feed, food, cosmetic and pharmaceutical products, and biofuel production, including biodiesel, bioethanol, and hydrogen:

• Construction of a low-cost, semi-closed cascade-type photobioreactor (PBR) to maximize the absorption and use of photosynthetically active radiation while minimizing contamination.
• Integration of a system for generating CO2 microbubbles, or microbubbles from other CO2-rich gaseous pollutants, to retain CO2 within the culture and minimize its release into the atmosphere. This increases the maximum rate of photosynthetic conversion of solar radiation into organic matter, resulting in a substantial increase in productivity.
• Use of gaseous pollutants from internal-combustion engines, thereby contributing to the reduction of industry’s environmental footprint.
• Use of brackish water and secondary-treated effluent from municipal wastewater treatment facilities.
• Comparative operation of two PBRs, under reference and pollutant-recycling conditions, to assess their operating costs.

Research organizations with advanced and complementary expertise collaborate to achieve the following main objectives:

• Identification, at laboratory scale, of the optimal conditions for cultivating C. vulgaris at brackish-water salinities and under different light intensities, CO2 concentrations, and municipal-wastewater concentrations.
• Optimization of C. vulgaris cultivation in a greenhouse PBR based on the laboratory results, together with quality control of the resulting microalgal biomass.
• Development of microbubble arrays for the dispersion of CO2 and gaseous pollutants.
• Innovative computational processing and dissemination of data within the framework of a PBR operating-cost analysis.