Long-term tetrachlorethene degradation sustained by endogenous cell decay
Bibliographic record
Abstract
The role of endogenous decay in the reductive dechlorination of tetrachlorethene (PCE) was studied in a sand column containing an anaerobic microbial consortium that included Dehalococcoides ethenogenes. The column consortium had continuously transformed PCE to vinyl chloride (<5%) and ethene (>95%) with the addition of ethanol and yeast extract for a 3 year period. The column was operated for a further period of 1 year with the addition of 60 µM PCE only. In the absence of external electron donors, PCE dechlorination in the column initially slowed but continued at a relatively constant rate for 1 year. The conversion to vinyl chloride (VC) and ethene (ETH) was significantly reduced with cis-dichloroethylene (cis-DCE) becoming the major (90%) end product of dechlorination. Microcosm studies, with no external electron donor added, indicated that reductive dechlorination was sustained by reducing equivalents derived from endogenous decay products. Measures of cellular adenosine triphosphate (ATP) along the length of the column indicated that even after 1 year of only PCE addition, an active biological community was sustained. Key words: tetrachloroethene (PCE), ethanol, anaerobic biodegradation, endogenous decay, column study.
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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".