title: Optimization of CO₂ fixation by Chlorella kessleri cultivated in a closed raceway photo-bioreactor.
abstract: The aim of this study is to optimize biological fixation of CO2 using Chlorella kessleri cultivated in oil sands process water (OSPW). A lab-scale closed raceway photobioreactor was designed and assembled for cultivation of C. kessleri in OSPW. A fed-batch model describing the dynamics of microalgae growth and CO2, phosphate and ammonium uptake rate was developed based on batch kinetics identified in our previous study, and was successfully validated against experimental data. A model-based optimization method was used to calculate the optimal feeding strategies for CO2, phosphate and light intensity which resulted in a 1.5-fold increase in the final biomass concentration and a 2-fold increase in the average CO2 uptake rate in 240 h (10 days) compared to the initial fed-batch experiment over 432 h (18 days). Finally, scale-up to large-scale continuous operation was considered, and the optimal hydraulic retention time (HRT) and feeding strategy for maximum productivity were estimated.
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Kasiri
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta T6G 2W2, Canada.
authors.forename: Ania
authors.initials: A
authors.lastname: Ulrich
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada. Electronic address: vprasad@ualberta.ca.
authors.forename: Vinay
authors.initials: V
authors.lastname: Prasad
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D057965:Carbon Sequestration; D002708:Chlorella / Q000254:growth & development* / Q000378:metabolism*; D007700:Kinetics; D008027:Light; D058086:Microalgae / Q000254:growth & development / Q000378:metabolism; D008962:Models, Theoretical; D061329:Oil and Gas Fields; D010710:Phosphates / Q000378:metabolism; D058433:Photobioreactors
chemical_list: D010710:Phosphates; D002245:Carbon Dioxide
keywords: CO(2) fixation; Closed raceway photobioreactor; Fed-batch and continuous cultures; Mathematical model; Optimal feeding strategy