Performic acid (PFA): tests on an advanced primary effluent show promising disinfection performance
Bibliographic record
Abstract
Performic acid, or PFA (CH(2)O(3)), is a well-known oxidizing agent and disinfectant in the medical field and food industry. It has recently become available on a commercial scale for potential use in wastewater disinfection. This study investigated its application to an advanced primary effluent which is recalcitrant to disinfection by UV and peracetic acid (PAA). Methods were developed for determining PFA concentrations in stock solutions as well as in residual concentrations in the wastewater. Batch and continuous-flow pilot studies showed a correlation between log fecal coliform removals and PFA doses. A PFA dose of approximately 3.4 mg/L and a contact time of 45 minutes could achieve 3-logs removal, and almost total disinfection could be achieved using a dose of 6 mg/L. The by-products of PFA addition are hydrogen peroxide and formic acid (CHOOH), neither of which is considered to be toxic to aquatic fauna at the doses required for disinfection.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".