Enhanced biodiesel production from microalgal biomass cultivated in optimized dairy and domestic wastewater mixtures

This is the authors' abstract. We don't add key points for this paper.

Microalgae cultivation in mixed wastewater could reduce contaminants, offer sufficient micronutrients for algal growth, and provide biomass for biofuel production. Thus, this study used different raw dairy and primary domestic wastewater ratios for Tetradesmus dimorphus GEEL-06 cultivation. The physicochemical properties of wastewater, microalgal growth kinetics, and nutrient removal were examined. The microalgal biomass was also analyzed for fatty acids and biodiesel qualities. The strain T. dimorphus GEEL-06 reached 1.426 g L−1 biomass yield, removing 97.20% total nitrogen and 94.61% total phosphorus in 40% dairy and 60% domestic wastewater. The main fatty acids in microalgal biomass were palmitic, linoleic, and stearic. Biodiesel quality (cetane number >57, iodine value <69) was achieved at 40% dairy wastewater dilution, maximizing saturated and minimizing unsaturated fatty acids. This study showed that microalgae grown in mixed dairy and domestic wastewater dilutions supported the wastewater–microalgae coupling approach.