Simulation of Arthrospira Growth and Nutrient Content in a 3,000-L Outdoor Raceway Cultivation Pond

          Arthrospira is a cyanobacterium containing rich protein content (over 50% of dry weight), and it is widely utilized commercially. The management of algae cultivation is crucial for reducing production costs by optimizing biomass yield and nutrient utilization. Algae growth prediction ahead of time enables regulation of the parameters of cultivation, resulting in effective cultivation management. This study developed a mathematical model comprising an algal growth model and a solar irradiance model to predict Arthrospira growth in a Raceway Pond (2x9x0.5 m, with a working volume of 3,000 L) under outdoor conditions.  The model used the volumetric distribution of algae to determine the average light exposure in the pond. Based on the measured data, the solar irradiance model, which employs latitude, longitude, date, and time as inputs, accurately predicted average solar radiation. Furthermore, the model effectively forecasted algae biomass production and nutrient concentrations inside the pond, demonstrating strong agreement with experimental results. This developed model will be applied to optimize algae cultivation management in outdoor conditions, enhancing production efficiency and sustainability.

Keywords: Algal cultivation, Mathematical model, Productivity, Arthrospira