MICROBIAL CHARACTERIZATION OF METHANOGENIC SLUDGE IN THE ANAEROBIC CO-DIGESTION OF SUGARCANE VINASSE AND LIQUID PIG MANURE

• Grant number: 25/07042-8
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: June 20, 2025
• End date: September 19, 2025
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Lucas Tadeu Fuess
• Grantee: Geovanna Damacena da Silva Galdino
• Supervisor: Claudia Etchebehere
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Uruguay
• Associated to the scholarship: 24/17099-4 - optimization of alkalinization and methane production from the anaerobic co-digestion of sugarcane vinasse and swine waste in batch reactors, BP.IC

Abstract

The project aims to microbially characterize the methanogenic sludge from the anaerobic co-digestion of sugarcane vinasse with liquid pig manure, in order to understand the microbiota involved and their influence on biogas production and process efficiency. Anaerobic digestion is a sustainable alternative for treating vinasse, a highly polluting waste generated in large volumes by the sugarcane-to-alcohol industry. However, challenges such as high organic loads and the need for nutritional balance still limit the efficiency of reactors. Co-digestion with liquid pig manure can mitigate these problems, since this waste contains nutrients that favor the stability of the system, as well as having the potential to buffer reactors fed with vinasse, eliminating the need to dose alkalis. Despite this, there is still little knowledge about microbial interactions in these hybrid systems. To better understand these processes, the study will evaluate two forms of vinasse, fresh and fermented, combined with three different proportions of liquid pig manure (90:10, 75:25 and 50:50), as well as control tests of mono-digestion of vinasse with sodium bicarbonate. Biomass samples will be collected from all reactors for microbiological analysis. The study will be carried out at the Instituto de Investigaciones Biológicas Clemente Estable (IIBCE) in Uruguay, under the supervision of Dr. Claudia Etchebehere, a specialist in the microbiology of anaerobic digestion. The research will foster collaboration between Brazilian and Uruguayan groups, promoting the development of new technologies for the bioenergy sector. With the results obtained, it is hoped to identify key microorganisms and their functions in the process, making it possible to optimize high-rate anaerobic reactors and reduce the need for chemical additives. (AU)