Biohydrogen production from wastewaters in anaerobic structured bed reactor: understanding the role of the fixed bed and its influence on the acidogenic microbial community

• Grant number: 19/11012-6
• Support type: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2019
• Effective date (End): April 30, 2021
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Marcelo Zaiat
• Grantee: Matheus Neves de Araujo
• Home Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery, AP.TEM

Abstract

Giving the growing global demand for natural resources, associated with the limitations in fossil resources availability, the search for renewable energy sources and feedstocks becomes imperative to maintain the continuous technological development. In this context, the concept of biorefinery applied in the treatment of wastewaters characterizes a promising alternative due to the potential to obtain value-added products from low cost waste streams. Fermentative processes may be directed for producing biohydrogen (bioH2) and other value-added metabolites through the anaerobic processing of wastewaters. Despite the proven suitability of fermentative processes within the biorefinery concept, several aspects still require further investigations to provide an effective techno-economic feasibility, such as establishing continuous and stable bioH2 production levels. Among different available reactor configurations, anaerobic structured-bed reactors (AnSTBR) have demonstrated the potential to maintain stable and continuous bioH2 production levels by providing a better control in the dynamics of biomass accumulation. This tends to prevent the establishment of undesirable metabolic pathways compared to conventional packed-bed reactors. However, ongoing studies have led to questions regarding the effective role of the fixed bed in bioH2-producing AnSTBR sytems, showing a massive conversion of fresh substrate (sugars) prior to the fixed bed region. In this context, this study aims to assess the role of the fixed bed in the thermophilic bioH2 production using the AnSTBR as acidogenic system. Dynamics of biomass growth and distribution, metabolite production and microbial characterization will be applied in continuous systems with different fixed bed heights, providing a holistic understanding of the fermentative process. (AU)