Comparative analysis of the bioremediation potential and pigment production by the microalga Spirulina maxima in an airlift reactor under batch and semi-continuous cultivation

• Grant number: 24/17182-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Daniela Helena Pelegrine Guimarães
• Grantee: Thiago Oliveira Hess
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

The use of microalgae, such as Spirulina maxima, for producing biofuels and value-added products has driven the development of new technologies. However, its cultivation is costly due to the high demand for nutrients. An alternative to reduce costs is the use of alternative macronutrient sources, such as effluents. The main objective of this project is to evaluate the bioremediation potential of the microalga Spirulina maxima cultivated in landfill leachate and optimize pigment production by this species in a semi-continuous reactor. Initially, it will be necessary to study the behavior of this microalga in a batch reactor, where the effects of leachate concentration, CO2 concentration in the cultivation feed stream, aeration flow rate in the reactor, and LED wavelength will be evaluated using a Taguchi L9 orthogonal array. The response variables will be the potential for bioremediation and productivity in biomass and pigments. Based on the results from the batch cultivations, cultivation in a semicontinuous reactor will be initiated to increase biomass and pigment productivity. This will involve assessing the effects of leachate concentration, CO2 concentration in the cultivation feed stream, aeration flow rate in the reactor, and feed flow rate (following the determination of specific growth rate in the batch cultivations), also using a Taguchi L9 orthogonal array, with potential for bioremediation and productivity in biomass and pigments as the response variables. The bioremediation potential of Spirulina maxima in both batch and semicontinuous cultivations will be evaluated using techniques for measuring Chemical Oxygen Demand (COD) and analyzing heavy metals.