Analysis of Chlorella vulgaris cultivation in a landfill environment: potential for bioremediation and chlorophyll and carotenoid synthesis

• Grant number: 24/21193-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: March 31, 2026
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Daniela Helena Pelegrine Guimarães
• Grantee: Pedro Carvalho Galindo
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

The increasing accumulation of solid waste over the past decades has led to a rise in leachate generation in landfills. This liquid, resulting from the decomposition of waste, carries toxic substances that can contaminate both the soil and water resources, raising serious environmental concerns. To address this challenge, sustainable alternatives for leachate treatment are being explored, such as the cultivation of microalgae and cyanobacteria, which utilize the nutrients present in the leachate, facilitating its bioremediation and generating biomass with potential as a source of pigments and carotenoids. Among the microalgae, the Chlorella genus, particularly Chlorella vulgaris, stands out due to its freshwater nature, eliminating the need for salt addition to the cultivation medium, which simplifies and reduces the costs of the process. This project aims to investigate the bioremediation potential of Chlorella vulgaris cultivated in landfill leachate in a semicontinuous reactor, as well as to optimize the production of pigments from this species. Initially, a batch study will be conducted, evaluating the effects of variables such as (i) LED light wavelength, (ii) aeration rate, (iii) CO¿ supply and (iv) leachate concentration, applying the Taguchi L9 orthogonal array. The response variables will include bioremediation potential and biomass and pigment productivity. With these data, the cultivation will then be carried out in a semicontinuous reactor, aiming to increase biomass and pigment productivity, while considering the effect of feeding flow rate, after determining the specific growth rate in the batch experiments. The maximum bioremediation potential of Chlorella vulgaris will be evaluated using DQO techniques and heavy metal analysis.