This study aims to investigate the effect of simultaneous carbon dioxide (CO₂) addition and biomass recycling on specific performance parameters (including biomass productivity and harvestability, and species abundance) of the mixed culture of two freshwater microalgae species Chlorella vulgaris and Scenedesmus obliquus in a flat-panel photobioreactor grown semicontinuously using secondary effluent urban wastewater as the culture medium. Recycling a portion of the gravity-harvested biomass back to the system has positive effects on biomass productivity and harvestability by letting microalgal cells utilize more of the available light energy and promoting the dominance of settleable microalgal species of S. obliquus (owing to their large cell sizes) in the mixed culture. Furthermore, CO₂ addition could supply the carbon limitation of urban wastewater and boost biomass production.

中文翻译：

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CO2同时添加和生物量回收对微藻混合培养生长特性的影响

本研究旨在研究同时添加二氧化碳 (CO ₂ ) 和生物量回收对两种淡水微藻物种Chlorella vulgaris和Scenedesmus３．平板光生物反应器使用城市二次污水作为培养基半连续生长。通过让微藻细胞再循环重力收获的生物质回系统的一部分已经生物质生产力和收获性积极效果利用更多的可用光能量的和促进的沉淀的微藻物种的优势S.斜（由于它们的大细胞尺寸）在混合培养中。此外，CO ₂添加可以提供城市废水的碳限制并促进生物质生产。