Department of Chemical Engineering, University of Almería, 04120, Almería, Spain.
CIESOL Solar Energy Research Centre, Joint Centre University of Almería-CIEMAT, 04120, Almería, Spain.
Sci Rep. 2021 Nov 4;11(1):21651. doi: 10.1038/s41598-021-01163-z.
The depth of the culture and the dilution rate have a striking effect on the biomass productivity and the nutrient recovery capacity of microalgal cultures. The combination of culture depth and dilution rate that allows to maximise the performance of the system depends on environmental conditions. In the current study, a response surface methodology was used to explore the relationship between the two most relevant operational conditions and the biomass productivity achieved in 8.3 m pilot-scale raceways operated using urban wastewater. Four polynomial models were developed, one for each season of the year. The software predicted biomass productivities of 12.3, 25.6, 32.7, and 18.9 g·m·day in winter, spring, summer, and autumn, respectively. The models were further validated at pilot-scale with R values ranging within 0.81 and 0.91, depending on the season. Lower culture depths had the advantage of minimising nitrification and stripping but allow to process a lower volume of wastewater per surface area. Biomass productivity was higher at culture depths of 0.05 m, when compared to 0.12 and 0.20 m, while the optimal dilution rate was season-dependent. Results reported herein are useful for optimising the biomass productivity of raceway reactors located outdoors throughout the year.
深度和稀释率对微藻培养物的生物量生产力和营养物回收能力有显著影响。允许最大化系统性能的培养深度和稀释率的组合取决于环境条件。在本研究中，使用响应面法来探索两个最相关的操作条件与使用城市废水在 8.3 米中试规模环道中实现的生物量生产力之间的关系。为每个季节开发了四个多项式模型。软件预测冬季、春季、夏季和秋季的生物量生产力分别为 12.3、25.6、32.7 和 18.9 g·m·day。根据季节的不同，模型在中试规模的验证 R 值范围在 0.81 到 0.91 之间。较低的培养深度有利于最小化硝化和吹脱，但允许每单位面积处理较少的废水量。与 0.12 和 0.20 m 相比，在 0.05 m 的培养深度下生物量生产力更高，而最佳稀释率则取决于季节。本文报告的结果有助于优化全年户外环道反应器的生物量生产力。
