Integration of Aquaculture Wastewater Treatment and Chlorella vulgaris Cultivation as a Sustainable Method for Biofuel Production

The integration of microalgae cultivation in the treatment of aquaculture wastewater (AWW) offers a sustainable solution for the recovery of nutrients and the valorisation of biomass. In this study, the potential of Chlorella vulgaris for growth in raw AWW and its variants was investigated and the efficiency of nutrient removal, biochemical composition of biomass, biodiesel potential by FAME analysis, and biogas production were evaluated. C. vulgaris was cultivated in three media: raw AWW, microelement-enriched AWW, and a synthetic base medium. Raw AWW allowed for the highest biomass production (2.4 g VS/L) and nutrient removal efficiency (ammonia: 100%, phosphate: 93.7%, nitrate: 37.8%). The addition of microelements did not significantly improve growth or nutrient uptake. The biomass grown on AWW showed a favourable lipid profile for biodiesel, dominated by C16:0 and C18:1. The highest biogas and methane yields were recorded for biomass from raw AWW as 358 ± 11 L/kg VS and 216 ± 7 L/kg VS, respectively. The results confirm that AWW is a suitable medium for the cultivation of C. vulgaris, enabling efficient wastewater treatment and the production of high-quality biomass.