Aproveitamento de glicerol como suplemento nutricional no desenvolvimento de microalgas : prospecção para obtenção de biomassa e lipídios.

Abstract

Mixotrophic microalgae systems present great potential in the production of bioenergy and wastewater treatment. The use of alternative sources in the microalgae growth, such as glycerol, is important because it minimizes economical and environmental impacts generated in biomass production. In order to increase the biomass production and consequently the lipid content, aiming its use at the biodiesel production, glycerol was used as a carbon source for the microalgae cultivation from the Wastewater Treatment Plant-UNISC. This study was carried out at the microalgae laboratory from the Excellence Center of Oleochemical and Biotechnological Products and Processes (ECOBPP), University of Santa Cruz do Sul (UNISC), Santa Cruz do Sul campus. The microalgae behavior present in the effluent was tested, In laboratory scale, using glycerol at concentrations of 2,6; 5,2 and 10,4 g L-1. In this scale, the concentration that had the best biomass yield was 2,6 g.L-1, presenting an average of 0.364 ± 0.082 g L-1. The sample with supplementation of 2 g.L-1 obtained the highest concentration of lipids with an average of 0.116 ± 0.030 L-1. The glycerol concentrations tested in the pilot scale study were the 7,5; 10,4 and 12,5 g.L-1, and the concentration of 12,5 g.L-1 had the best yield rate (3.778 ± 1.1210 g.L-1) in biomass, and (0.135 ± 0.008 g L-1) for lipids. Regarding the profile of fatty acids found in both experiments, it was observed that in general occurred an increase of this profile with addition of glycerol as, for example, C14: 0, C18: 0, C18: 2, C20: 0, among others. However, it is noteworthy that in general both conditions presented an oil chromatographic profile with good quality for biodiesel production.