Improving CO2 fixation with microalgae by bubble breakage in raceway ponds with up-down chute baffles

Area of Science:

• Biotechnology
• Aquaculture Engineering
• Microalgae Cultivation

Background:

• Microalgae cultivation in raceway ponds is crucial for biofuels and bioproducts.
• Efficient carbon dioxide (CO2) fixation is essential for maximizing microalgae biomass yield.
• Aeration strategies significantly impact CO2 transfer and microalgae growth.

Purpose of the Study:

• To investigate the effect of up-down chute baffles on aeration bubble characteristics in microalgae raceway ponds.
• To optimize aeration parameters for enhanced CO2 fixation and microalgae biomass production.
• To quantify the impact of modified bubble dynamics on microalgae yield.

Main Methods:

• Utilized high-speed photography to analyze bubble generation and residence times.
• Employed online precise pH probes for real-time monitoring of aeration efficiency.
• Varied parameters including paddlewheel speed, aerator orifice diameter, gas flow rate, and solution depth.

Main Results:

• Up-down chute baffles enhanced local solution velocity, reducing bubble generation time by up to 27%.
• The generated vortex flow field increased bubble residence time by up to 27%.
• Optimized flow fields resulted in a 29% increase in microalgae biomass yield.

Conclusions:

• Modified aeration bubble dynamics through baffle implementation significantly improve CO2 fixation in microalgae raceway ponds.
• The study demonstrates a practical method for enhancing microalgae productivity through fluid dynamics optimization.
• Findings provide valuable insights for designing efficient raceway pond systems for large-scale microalgae cultivation.