Investigation of lakes sediment and solar-integrated photo-bioreactors effect on the lipid production from Spirulina platensis

Abstract

The main objectives of the current research assess how engineering and environmental factors affect the production of lipids oil from Spirulina (Arthrospira platensis) in solar-integrated photo-bioreactors.In addition, the effects of media type (freshwater vs. seawater), sediment concentration 10 g/l/day (1%), and cultivation duration (4-18 days) on microalgal growth and lipid accumulation were evaluated using laboratory-scale (1 L and 6 L) and outdoor modular (6 × 18.9 L) photo-bioreactors.Sediment concentration decreased lipid percentage by about 10% for every 10 g/l/day more sediment (1%), whereas freshwater media consistently produced higher lipid content, reaching a maximum of 7.96 ± 0.04% after 18 days.The results indicate that integrating solar-powered photobioreactors for sustainable microalgae lipid production is technically feasible, underscoring the significance of reactor design and environmental optimization for biofuel applications.In laboratory settings, LED lighting greatly improved lipid synthesis, and freshwater media consistently performed better than seawater.Model 1 showed very high predictive accuracy (r≥0.999) for freshwater systems in both the lab and the field.Freshwater yields steadily increased over time, whereas seawater production decreased significantly after 14 days.These results indicate that using freshwater media and Model 1 together is the best way to obtain the most lipids.The study presents controlled sediment dosing as a new strategy for microalgal cultivation with potential for low-cost and sustainable nutrient supply, such as the traditional approaches based on synthetic media or wastewater supplementation and environment-friendly biofuel production systems.Furthermore, this study investigated the direct application of natural sediments to stimulate lipid accumulation.