Purification of potato wastewater and production of byproducts using microalgae Scenedesmus and Desmodesmus

Microalgae have the ability to grow rapidly in wastewater to remove pollutants and produce pigments. This study was carried out to identify candidate microalgae with high pigment content and powerful purification capacity for potato wastewater. Eight species (five Scenedesmus and three Desmodesmus) were tested in a laboratory experiment. The results showed that Scenedesmus sp. HXY5 grew best in potato wastewater within 7 days, yielding the highest biomass (2.64 g L−1). Scenedesmus sp. HXY5 also exhibited excellent wastewater purification ability, achieving removal efficiencies of 59%, 32%, and 93% for total dissolved nitrogen, total dissolved phosphorus, and chemical oxygen demand, respectively. Additionally, Scenedesmus sp. HXY5 achieved the highest total pigment yield (18.45 mg L−1), with a lutein yield of 11.46 mg L−1. Our results indicated that Scenedesmus sp. HXY5 showed great potential for purifying potato wastewater and producing pigments.