Microbial Population and Degradation Activity Changes Monitored During a Chlorinated Solvent Biovent Demonstration
Bibliographic record
Abstract
Abstract Microbial populations and degradation activity increased significantly during a chlorinated solvent bioventing bioremediation effort using propane at Dover Air Force Base in Delaware. The propane injection resulted in degradation of a mixture of chlorinated solvents, including trichloroethylene (TCE), cis‐dichloroethylene (c‐DCE), and 1,1,1‐trichloroethane (TCA). In only 20 d, the propane injection resulted in decreases of TCE and c‐DCE of > 98%, and a decrease in TCA in soil gas by ∼70%. The degradation of the TCA may not have occurred with a methane, butane, toluene, or phenol injection. These decreases in chlorinated solvent concentrations were accompanied by large increases in propane‐utilizing bacteria that ranged from below detection levels prior to the injection to ∼1% of the ending total aerobic heterotrophic population by the end of the propane injection. Thus, a proportional increase occurred as heterotrophic counts increased a hundredfold. Microbial TCE degradation activity, as measured in microcosms, also increased with the propane injection. The highest rates of degradation were observed in microcosms with propane and nutrients, indicating the potential for higher field rates of degradation with nutrient additions.
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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 | 0.001 |
| 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".