Bioremediation potential of Lake Victoria microalgae species in the treatment of dairy processing facility wastewater

Abstract

Dairy wastewater poses a threat to the health of aquatic ecosystems in Sub-Saharan Africa (SSA) due to its pollution potential. Microalgae present a promising bioremediation potential by removing nutrients and organic carbon from wastewater. However, there is paucity of information supporting the potential of microalgae in treatment of dairy wastewater. The study compared the efficiency of microalgae species in removing organic and nutrient pollutants from wastewater. Wastewater samples were collected from the Uganda Industrial Research Institute (UIRI) dairy processing plant. Microalgae genera were i solat ed from the sampl es via singl e-cel l  mi cr opipet t e met hod. Scenedesmus spp., Chlorella spp. and Selenastrum spp. were successfully isolated and cultured. Scenedesmus spp. showed excellent performance in nutrient removal and biomass production, achieving reductions of 92.6% in chemical oxygen demand, 88.2% in organic carbon, 80.9% in total nitrogen, and 90.8% in total phosphorus from initial levels of 969.33, 148.94, 33.21 and 86.58 mgL, respectively. Over a 12-day cultivation period, Scenedesmus spp. achieved a peak dry biomass yield of 1.04 gL-1, at an average dry biomass generation rate of 0.087 g L -1  day-1. Chlorella spp., performance was not far behind that of Scenedesmus spp. The results achieved highlight the potential of microalgae in treating diary wastewater with simultaneous biomass production. Microalgae based systems would be a sustainable solution for dairy wastewater treatment, aligning with Goal Six of the United Nation’s Sustainable Development.