Enhancing Energy Utilization and Production Efficiency of Spirulina sp. in a Thin-Layer Fountain Photobioreactor Using a Novel Variable-Frequency Mixing Technology

作者：Mingjing Zhang, Jialin Wang, Chen Hu, Jihua Liu, Yongxiu Huang, Xiaoyu Guo, Wenluo He, Wenbo Luo, C Li, Lei Li, Nianzhi Jiao, Chenba Zhu · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.5c04267 · 被引用次数：5 · 研究领域：Algal biology and biofuel production、Light effects on plants、Solar-Powered Water Purification Methods

Thin-layer fountain photobioreactors (TLF-PBRs) are an attractive option for low-cost microalgal production and efficient carbon capture due to their low cost, high biomass density, productivity, and ease in scaling up. To further enhance their production performance and reduce energy inputs, this study develops a novel variable-frequency mixing technology (VFMT). This technology continuously varies the spray radius in a reciprocating cycle, ensuring uniform coverage of the entire cultivation area to improve overall mixing within the TLF-PBR. The VFMT was first tested by culturing Spirulina sp. in a 50 cm diameter TLF-PBR under continuous artificial lighting (314 μmol·m –2 ·s –1 ), with liquid layer thicknesses ranging from 1.0 to 5.0 cm. The results revealed that the VFMT simultaneously increased biomass productivity by 9.34–40.93% and reduced mixing energy consumption by 27.73%, compared to the controls with a constant spray radius. The maximum areal productivity of 36.30 g·m –2 ·day –1 was achieved in the VFMT-based culture with a thickness of 2.5 cm, which was 9.34% higher than the control (33.2 g·m –2 ·day –1 ). The VFMT was successfully applied to a 150 cm-diameter TLF-PBR under continuous artificial lighting (150 μmol·m –2 ·s –1 ), achieving a maximum cell density of 5.42 g·L –1 and an areal productivity of 30.2 g·m –2 ·day –1 . These values exceeded the control (4.76 g·L –1 and 28.2 g·m –2 ·day –1, respectively) while reducing the mixing energy consumption by 20.8%. T...