Kinetics of biofilm nitrification

✍ Scribed by H. Tanaka; I. J. Dunn

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 768 KB
• Volume: 24
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260240311

✦ Synopsis

Abstract

The reaction rates (r and r) in the two‐step nitrification reaction were measured in a fluidized‐sand‐bed biofilm reactor under a range of steady‐state conditions with respect to bulk NH, NO, and O~2~ concentrations. It was shown from theory and experiment that under low NH concentration conditions, if the O~2~/NH concentration ratio in the bulk liquid is less than the stoichiometric coefficient (3.4 mg/mg), then oxygen will be rate limiting. In all experiments r decreased more than r under low oxygen conditions. This resulted in high NO effluent concentrations under low residence time conditions. The influence of the oxygen penetration effects on the relative values of r and r was experimentally shown to be caused either by the Nitrobacter location in the inner biofilm regions or by a K~m~ effect for oxygen. Theoretical support of these findings was provided by a differential diffusion‐reaction model which was used to simulate the experimental results.