Exploring the role of hydrogen peroxide in the microwave advanced oxidation process: solubilization of ammonia and phosphates
Bibliographic record
Abstract
The focus of this study was to investigate the combined effects of hydrogen peroxide concentration and acid hydrolysis on ammonia and ortho-phosphate solubilization for subsequent struvite formation. A lower microwave temperature regime between 60 and 120 °C was of interest in this study because of the greater amount of polyphosphates found in the treated secondary sludge at these temperatures. At microwave-heating temperatures of 100 °C and 120 °C, it was found that increasing the hydrogen peroxide concentration resulted in an increased phosphorus and ammonia solubilization. At a reaction time of only 5 min, the combination of hydrogen peroxide and acid hydrolysis resulted in up to 61% of total phosphorus and 36% of TKN released into solution, as soluble ortho-phosphate and ammonia, respectively. The amount of soluble nitrogen in solution after microwave treatment was found to increase with the hydrogen peroxide concentration. Up to 39% of the total soluble nitrogen could be released into solution. Furthermore, the addition of hydrogen peroxide resulted in a dramatic decrease in the PO4:NH3 molar ratio, an important factor controlling struvite formation. In terms of facilitating poly-P breakdown into ortho-phosphate in the acid hydrolysis process, hydrogen peroxide was found to be the most effective at 80 °C and at a concentration of 1.5 wt% H2O2. At temperatures of 100 and 120 °C, the amount of soluble ortho-phosphate increased with the hydrogen peroxide concentration. Key words: advanced oxidation process, ammonia nitrogen, hydrogen peroxide, microwave, phosphorus release, sludge, struvite.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".