NH4+ removal with Nitritation/Anammox, full scale experience and challenges
Event details
| Date | 22.11.2011 |
| Hour | 16:15 |
| Speaker | Dr Adriano Joss, EAWAG |
| Location |
GR C0 01
|
| Category | Conferences - Seminars |
Combined nitritation-anammox in a single sequencing batch reactor has been confirmed as an attractive option for nitrogen removal in high-strength wastewater due to the low specific costs of nitrogen removal, so that many full-scale projects are currently being realized. Now that anammox-based N-removal has been shown to reduce costs and energy consumption compared to denitrification-based processes, its process stability appears to be the major issue making operators reluctant to opt for this process.
The start-up times required at full scale have decreased dramatically in recent years, confirming the progress made in terms of better understanding of the process as well as by empirically testing new operation strategies: Abma et al. used a granular reactor to show the feasibility of anammox start-up with an increase of observed performance (0.055 d 1) close to the maximum growth rate observed in the lab (0.06 d 1). Additional full-scale examples confirm that start-up no longer requires years but can now be regarded as a well-controlled and reliable procedure lasting no more than several months.
Further aspects currently under active discussion are a comparison of reactor configurations and process control options: single-stage vs. two-stage reactors (i.e. with segregated nitritation and anammox stages), suspended growth vs. attached biofilm or granular reactors, selection of sensors required for process control and a detailed strategy for embedding these sensors in automated process control systems are among the topics most actively pursued both in the labs and in full-scale operation. According to the authors' knowledge, such direct comparisons of different options are still difficult, since the various treatment schemes are still being optimized.
The present work discusses full-scale data of suspended sludge nitritation-anammox reactors with the help of lab experiments as a contribution to understanding process stability issues. Some options for improved process control in treatments combining nitritation and anammox in a single reactor are presented. We aim to contribute to the applicability of the process as well as providing a sound basis for discussing the suitability of alternative processes.
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Practical information
- General public
- Free
Contact
- Prof. Christof Holliger, LBE