Anaerobic co-digestion of residual glycerol with sanitary sewage in a pilot scale hybrid reactor aiming at enhancement of biogas production

Author(s)

Caroline de Cássia Banci Garcia

• Document type: Master's Dissertation
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2019-04-12

Examining board members

Eugenio Foresti; Moacir Messias de Araujo Junior; Ariovaldo José da Silva

• Advisor: Eugenio Foresti

Abstract

In many sewage treatment plants in Brazil, up-flow sludge blanket (UASB) reactors have been used to treat domestic sewage, although they have a low removal efficiency of chemical oxygen demand (COD) and high amount of solids in the effluent for this substrate. In addition, most of the installed UASB reactors has presented small biogas production due to the low influent organic matter concentration. However, biogas production can be increased by the anaerobic codigestion process, by adding a co-substrate to increase the influent organic matter concentration. Glycerol has been highlighted as a co-substrate for high methane generation potential due to its high concentration of readily biodegradable organic matter. It is intended to evaluate the possibility of using the methane production potential of UASB reactors already installed in Brazil, through the addition of glycerol to the influent sewage. The research was conducted in two stages, using UASB hybrid reactors, with volumes of 24.75 L in the first stage, and 1.46 L in the second stage. They were fed with sanitary sewage and UASB reactor effluent, respectively, maintaining the hydraulic holding time (TDH) constant at 8 hours and varying the dosage of affluent glycerol. The best phase of operation considering COD removal efficiency, methane production and biological system stability was operated with OLR of 2.09 ± 0.22 kg CODm-3.d-1 and methane yield of 75 ± 68 mLCH4.gCODremoved-1. (AU)

• FAPESP's process: 17/22476-8 - Anaerobic co-digestion of residual glycerol with sanitary sewage in a pilot scale hybrid reactor aiming at optimization of biogas production
• Grantee: Caroline de Cassia Banci Garcia
• Support Opportunities: Scholarships in Brazil - Master