Preferable Operational Range of External Selector to Attain Partial Nitritation in the Main Aeration Tank
Bibliographic record
Abstract
To attain mainstream nitritation in the aeration tank receiving low-strength wastewater, an external selector to reduce nitrite-oxidising organism biomass was investigated. In the selector, the highly thickened microorganisms transferred from the aeration tank via a mechanical solid-liquid separation were exposed to a poisonous compound and returned to the aeration tank, where a part of the nitrifiers were killed. Using a mixture with 1,000 mg-N L−1 of nitrite and 1,000 mg-N L−1 of ammonium, about 60% of nitritation based on the effluent nitrogen was successfully maintained in the lab-scale system for more than 150 days without significant accumulation of nitrate. The poisonous compound also led to the decay of ammonium-oxidising organism to a certain extent. However, by optimising recycle rate to the selector, solids retention time of the selector, and excess sludge withdrawal rate, selective wash-out of nitrite-oxidising organism was possible. From the experimental results, the preferable operational range of the selector was explored in contour plots using the modified IWA-ASM1 model. The model indicated the preferable external recycle rate and solids retention time of the selector were about 0.2–0.4 d−1 and 1–2 d, respectively, when the aeration tank was operated with excess sludge withdrawal of 0.1–0.17 d−1.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".