optimization of alkalinization and methane production from the anaerobic co-digestion of sugarcane vinasse and swine waste in batch reactors

• Grant number: 24/17099-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Lucas Tadeu Fuess
• Grantee: Geovanna Damacena da Silva Galdino
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/10615-1 - Consolidation of the biorefinery concept applied to the biological treatment of wastewater and solid wastes, AP.TEM

Abstract

Research within the context of sugarcane vinasse anaerobic digestion enabled anexpressive process improvement in the last decade, considering the definition of high-ratereactor configurations and operating conditions that "optimized" both the methane productionand the reduction in the polluting organic load. However, this success still depends on anefficient reactor alkalinization, which is often related to dosing neutralizing and/oralkalinizing compounds and makes system scale-up unfeasible on an economic basis. Amongpossible low- or zero-cost alternative alkalinization strategies, attention is given to the co-digestion of vinasse and liquid swine manure, a substrate that contains appreciable ammonialevels to be exploited as an alkalizing agent due to in loco generation of ammoniumbicarbonate in anaerobic environments. Because such nitrogen content can be toxic to theanaerobic process, mainly to methanogens, assessing different substrate proportions in co-digestion systems is necessary to define the best conditions for optimizing reactoralkalinization and maximizing methane production. This project aims to investigate thepotential use of liquid swine manure as an alkalizing agent and co-substrate in the anaerobicdigestion of sugarcane vinasse, assessing impacts on the kinetics of organic matter removaland methane production. The microbial characterization of biomass samples collected fromthe reactors will also be carried out in a step to be accomplished in the Instituto deInvestigaciones Biológicas Clemente Estable, Uruguay. From a technological point of view,this approach will be extremely relevant to guide future studies using continuous systems, inorder to enable the scale-up of high-rate anaerobic reactors that do not depend on chemicaldosing.