Abstract
This study was focused on evaluating the role and the effect of anoxic decay on the extent of simultaneous nitrification-denitrification (SNdN) process sustained in a single membrane bioreactor. The membrane bioreactor was fed with relatively strong domestic sewage and operated at steady state at a sludge age of 36 days at a corresponding suspended solids level maintained in the range of 17,500-21,000 mg/L. The SNdN could be sustained due to diffusion limitation of oxygen into the flocs. The evaluation identified an MLSS threshold level of around 17,000-18,000 mg/L below which nitrogen removal was essentially controlled by denitrification and above, the rate limiting mechanism shifted to nitrification maintaining total nitrogen removal efficiency of 85-95% for a typical domestic sewage. The contribution of anoxic decay process to the overall denitrification potential was evaluated as 60%, substantially higher than the remaining 40% associated with the anoxic growth during the SNdN process.
Original language | English |
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Pages (from-to) | 771-780 |
Number of pages | 10 |
Journal | Water Science and Technology |
Volume | 61 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2010 |
Externally published | Yes |
Keywords
- Anoxic decay
- Membrane bioreactor
- Modelling
- Simultaneous nitrification/denitrification