Model development for simultaneous nitrification and denitrification

The aim of this study is to simulate the behaviour of nitrogen and carbon compounds in a sequencing batch reactor (SBR) by incorporating a dynamic microbial flee model. The results have shown that both flee diameter and liquid phase concentration are important factors influencing the internal flee reaction rate. An integrated model of the SBR has been proposed in this paper, whereby reaction rates are determined as a function of internal flee concentrations. This enables the evaluation of the phenomena that occur due to internal flee effects such as simultaneous nitrification and denitrification (SND). Results support the hypothesis that SND is a physical phenomenon, and occurs due to oxygen diffusion limitations within flocs. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved