Micro-Oxygenation in Upflow Anaerobic Sludge Bed (UASB) Reactors Using a Silicon Membrane for Sulfide Oxidation
Freddy Valdés,
Priscila Rosseto Camiloti,
Jan Bartacek,
Álvaro Torres-Aravena,
Javiera Toledo-Alarcón,
Marcelo Zaiat,
David Jeison
Affiliations
Freddy Valdés
Departamento de Ingeniería Química, Universidad de La Frontera. Av. Francisco Salazar, 01145 Temuco, Chile
Priscila Rosseto Camiloti
Laboratory of Biological Processes, São Carlos School of Engineering, University of São Paulo (USP), 1100, João Dagnone Ave., Santa Angelina, 13.563-120 São Carlos, SP, Brazil
Jan Bartacek
Department of Water Technology and Environmental Engineering, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
Álvaro Torres-Aravena
Escuela de Ingeniería Bioquímica, Facultad de Ingeniería, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085 Valparaíso, Chile
Javiera Toledo-Alarcón
Escuela de Ingeniería Bioquímica, Facultad de Ingeniería, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085 Valparaíso, Chile
Marcelo Zaiat
Laboratory of Biological Processes, São Carlos School of Engineering, University of São Paulo (USP), 1100, João Dagnone Ave., Santa Angelina, 13.563-120 São Carlos, SP, Brazil
David Jeison
Escuela de Ingeniería Bioquímica, Facultad de Ingeniería, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085 Valparaíso, Chile
Sulfide produced by sulphate-reducing bacteria in anaerobic reactors can seriously affect biogas quality. Microaeration has become a reliable way to remove sulfide, by promoting its oxidation. However, limited research is available regarding its application in upflow anaerobic sludge bed (UASB) reactors. In this research, silicon membranes were studied as a mechanism to dose oxygen in USAB reactors. Two configurations were tested: the membrane placed inside the reactor or in an external module. Our results show that the external membrane proved to be a more practical alternative, providing conditions for sulfide oxidation. This led to a reduction in its concentration in the liquid effluent and biogas. External membrane configuration achieved a sulfide conversion rate of 2.4 g-S m2 d−1. Since the membrane was not sulfide-selective, methane losses were observed (about 9%). In addition, excessive oxygen consumption was observed, compared to the stoichiometric requirement. As is the case for many membrane-based systems, membrane area is a key factor determining the correct operation of the system.
