Spirulina Cultivation Using Biogas CO₂ as the Carbon Source: Preliminary Study on Biomass Growth and Productivity

¹ Department of Civil Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India
² Biorefinery and Process Automation Engineering Center, Department of Chemical and Process Engineering, The Sirindhorn ThaiGerman International Graduate School of Engineering, King Mongkut’s University of Technology North Bangkok, Thailand

^* Corresponding author: debrajb@ce.iith.ac.in

Abstract

Anthropogenic activities are causing a rapid increase in global carbon dioxide (CO₂) emissions, which significantly contribute to global warming. Microalgae can be a sustainable solution for simultaneous wastewater treatment and sequestering CO₂ through photosynthesis. The current study reports a comparative evaluation of Spirulina sp. microalgal biomass growth and lipid productivity during its cultivation supplied with air and biogas from an anaerobic digester. It was observed that there was a 4-fold increase in biomass productivity in the reactor sparged with biogas compared to air supply. The reactor sparged with biogas showed a significant increase in lipid content. This increase in biomass productivity could be attributed to the increased availability of CO₂, favoring algal growth.