Microalgae consortium for the treatment of pig slaughterhouse wastewater: A biorefinery approach

Abstract

This study explores the use of pig slaughterhouse wastewater (PSWW) as a culture medium for a microalgal consortium composed of Scenedesmus sp. and Chlorella vulgaris, cultivated for 13 days in flat photobioreactors under the atmospheric conditions of Quito. The aim was twofold: to assess the bioremediation potential of the system and to evaluate biomass production for energetic valorization. Daily sampling was conducted to monitor the removal of key physicochemical parameters from the wastewater. Following cultivation, the harvested biomass was processed for lipid and free fatty acid (FFA) extraction, as well as for fatty acid methyl ester (FAME) production. The system achieved removal efficiencies of 91.72 % for total nitrogen (TN), 61.93 % for total phosphorus (TP), and 81.71 % for total organic carbon (TOC). Biomass concentration reached 0.52 g/L, with a specific productivity of 0.077 d⁻¹ . Lipid and FFA contents of 24.88 % and 33.54 %, respectively, were obtained from dry biomass using methylcyclohexane as the extracting solvent. FAME production reached 56.64 %, with values approaching international biodiesel quality standards. These results demonstrate the potential of microalgal consortia for effective PSWW treatment and biomass valorization. The proposed approach offers a promising alternative within the framework of microalgae-based biorefineries, integrating wastewater remediation with the sustainable production of biofuels.