Comparative Assessment of Chlorella vulgaris Cultivation in Synthetic, Oligotrophic and Industrial Wastewater for Sustainable Biomass Production

Abstract

This study evaluates the physiological and biochemical responses of Chlorella vulgaris cultivated in synthetic BG11 medium, oligotrophic water, and industrial wastewater under controlled laboratory conditions with optimized pH and nitrogen-to-phosphorus (N:P) ratios. The highest cell density, growth rate, and pigment accumulation were observed in BG11 at neutral pH and higher N:P ratios. Moderately adjusted N:P ratios in industrial wastewater produced comparable biomass yields and improved photosynthetic efficiency, demonstrating its potential as a cost-effective medium for integrated wastewater treatment and algal biomass production. In contrast, oligotrophic water severely limited growth due to nutrient deficiency. FTIR analyses indicated that C. vulgaris maintains essential biochemical components under nutrient stress through adaptive metabolism. This comparative study provides new insights for designing scalable, sustainable microalgal cultivation systems that link biomass production with wastewater management within a circular bioeconomy framework.