Cultivation of chlorella vulgaris using aquaculture wastewater: Assessing its viability as a promising resource for biodiesel production

This study investigates the viability of utilizing Chlorella vulgaris cultivated in aquaculture wastewater as a feedstock for biodiesel production. The research involved scaling up the algal culture from 10 ml to 10 liters in a photobioreactor, optimizing growth conditions, and analyzing the water parameters of the aquaculture wastewater medium. The results showed successful growth of the algal culture, with the highest growth rate achieved on day 15 in the 10-liter reactor. The harvested biomass was converted into biodiesel through direct transesterification, and the produced biodiesel was characterized using Fourier-transform infrared spectroscopy (FTIR) and fuel property tests. The FTIR analysis confirmed the presence of functional groups indicative of esterification, validating the successful conversion of the wet biomass into biodiesel. The fuel property tests revealed that the algal biodiesel exhibited marginally higher kinematic viscosity but a favourable flash point compared to established standards. Emission tests demonstrated an increase in CO2 and hydrocarbon emissions with higher engine loads, aligning with combustion principles. The findings highlight the potential of utilizing aquaculture wastewater as a sustainable medium for cultivating Chlorella vulgaris and producing biodiesel, contributing to the development of more resource-efficient and environmentally friendly biofuel production methods.