Abstract
Abstract Microalgal cultivation in single wastewater limits their scale-up due to insufficient or extremely high nutrient levels. Thus, a combination of different wastewaters is a potential approach for microalgal cultivation, as it regulates the nutrient levels among the wastewaters. In this study, primary domestic wastewater (PDW) and primary piggery wastewater (PPW) were collected and subjected to comprehensive physicochemical characterization. The wastewaters were subsequently mixed at volumetric ratios of 1.25%, 2.5%, and 5% (PPW: PDW) to serve as growth media for microalgal cultivation. The optimal microalgal growth (1.105 g L− 1) and maximal nutrient removal efficiencies (93.58% total nitrogen; 97.74% total phosphorus) were highest in the 1.25% PPW treatment. Gas chromatography analysis revealed a predominance of four major fatty acids (FAs) as palmitic acid (33.18%), trans-9-elaidic acid (25.39%), linoleic acid (16.96%), and oleic acid (14.22%). The 1.25% PPW treatment showed particularly favourable biodiesel feedstock characteristics, evidenced by high monounsaturated fatty acid content (45.97% of total FAs) and dominant C16-C18 (97.64% of total FAs). The 1.25% PPW ratio was identified as the optimal condition, which significantly maximized nutrient removal, promising the potential for biodiesel production. The dual function of microalgal systems emphasizes their ability to produce high-value biomass while also treating wastewater.Graphical Abstract
NETL
NSTL
Springer Nature