Model of simultaneous denitrification and methanogenesis in an Upflow Packed-Bed Biofilm Reactor: Nitrogen compounds' inhibition and pseudo two-dimensional biofilm model

✍ Scribed by César Huiliñir; Estrella Aspé; Marlene Roeckel

• Publisher: Wiley (John Wiley & Sons)
• Year: 2009
• Tongue: English
• Weight: 380 KB
• Volume: 84
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.2033

✦ Synopsis

Abstract

BACKGROUND: The modelling of simultaneous denitrification and methanogenesis (DM) in upflow packed‐bed biofilm reactors (UPBR) and the effect of inhibition by nitrogen compounds on methanogenesis has received little attention. This study evaluated the effect using a model that incorporates a pseudo‐two‐dimensional biofilm model.

RESULTS: The model was validated through comparison with experimental data, and achieved deviations below 5% for the liquid and gas phases. The model indicated that biomass stratification exists throughout the reactor and within the biofilm interior. At C/N ratios close to the stoichiometric C/N ratio, the process achieves efficiencies greater than 70% for nitrogen load rate (NLR) < 270 mg NO~3~^−^‐N dm^−3^ h^−1^. At high C/N ratios (50 mg total organic carbon (TOC) mg^−1^ NO~3~^−^‐N), the process achieves efficiencies greater than 70% for organic load rate (OLR) < 83 mg TOC dm^−3^ h^−1^.

CONCLUSION: The inclusion of the inhibition of methanogenesis by nitrogen compounds did not improve the predictions. Indeed, mass transfer in the biofilm was the phenomenon that most influenced the process. At C/N ratios close to the stoichiometric C/N ratio, process efficiency depends on the NLR; while at high C/N ratios, process efficiency depends on the OLR. Copyright © 2008 Society of Chemical Industry