Emamshoushtari, M. M., Tavakoli, O., Harasek, M., Haddadi, B., & Pajoum Shariati, F. (2026). CFD–experimental assessment of open-tube airlift photobioreactors for CO₂ capture and nutrient removal. Journal of Environmental Chemical Engineering, 14(1), Article 120533. https://doi.org/10.1016/j.jece.2025.120533
Airlift photobioreactors; CFD; Gas holdup; Nitrate and phosphate removal; CO2 conversion
en
Abstract:
This study presents a novel open-tube airlift photobioreactor (PBR) designed with the support of computational fluid dynamics (CFD) and experimentally compared with closed-tube and wall reactors. A validated Euler–Euler CFD model was ≤ 5 % error, indicating enhanced gas holdup, circulation uniformity, and mass transfer in the open-tube geometry, achieving a volumetric mass transfer coefficient (kLa) of 0.037 s⁻¹ at Usg = 0.05 m.s⁻¹ . Flow analysis confirmed the reduced vortex formation and more streamlined riser–downcomer transitions, which promoted longer bubble residence times. Cultivation with Chlorella vulgaris showed enhanced biological performance: biomass concentration reached 1.8 g.L⁻¹ , nitrate removal was 55 %, phosphate consumption was nearly complete after 10 days, and CO₂ capture efficiency peaked at 85 %, outcompeting conventional flat-panel and bubble column PBRs (60–75 %). These results highlight the open-tube airlift PBR a potential platform for simultaneous CO₂ bio fixation, nutrient removal, and biomass production with high potential for sustainable wastewater treatment.
en
Research Areas:
Biological and Bioactive Materials: 30% Environmental Monitoring and Climate Adaptation: 30% Modeling and Simulation: 40%
