Analysis of halogenated flame retardants in Canadian wastewater treatment plants using gas chromatography–tandem mass spectrometry (GC-MS/MS)
Bibliographic record
Abstract
Abstract An investigation of brominated flame retardants (BFRs), polybrominated diphenylethers (PBDEs), and chlorinated flame retardants was conducted in samples from Canadian wastewater treatment plants (WWTPs). The penta-BDE mixture and deca-BDE were most commonly detected. Median removal efficiencies of PBDEs by WWTPs were 71% to 99% and higher concentrations of PBDEs were found in influent samples in summer, compared to winter. Three novel brominated flame retardants (nBFRs) including 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTeBB or TBB), and bis(2-ethyl-1-hexyl)tetrabromophthalate (BEHTBP or TBPH) were detected in greater than 80% of influents and biosolids. Median removal efficiencies were 45% to 99% for BTBPE, 63% to 99% for TBB, and 88% to 99% for TBPH. Detection of total dechlorane plus ((DP) syn and anti) was greater than 90% in both wastewater and biosolids samples. However, median removal efficiencies were between 51% and 66% for total DP. Overall, PBDEs were effectively removed via different treatment processes, while BTBPE, TBB, and DP exhibited lower removal rates, which could be due to their physical chemical properties.
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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 | 0.006 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.011 | 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".