Human Urine as an Alternative Source of nutrient for Biomass Production of Scenedesmus dimorphus

Abstract

Microalgae are known to produce an array of value-added components like pigments. The nutrient medium used to cultivate microalgae is generally more expensive. The prominence of this work is on the practicality of human urine as a low-cost source of nutrients for microalgae culture, as it includes major nutrients and minor minerals and is cost-effective. Of course, it is a digressive approach from the aesthetic point of view. Nevertheless, the ultimate products can be purified, obviating pathogenicity. Human urine was collected, sterilized and different dilutions were prepared (5%,10%,15%,25%,50%,75%,100%). Cultures of Scenedesmus dimorphus were inoculated into a diluted human urine medium and incubated for 15 days at room temperature (around 29ºC) under window spread sunlight. The concentrations of 5%, 10%, and 15% have supported the production of microalgae. The maximum biomass was observed in 5% human urine concentration with a cell density of 1.74×106 cells/mL with 3.2 g/L biomass production. The biomass productivity was 0.257 g/L /day. Growth cessation could be perceived at more than 25% of human urine concentration. This study offers scope for considering human urine for algal production, targeting value-added products, aside from obnoxious liquid waste utilization.