Degradation Rates for Petroleum Hydrocarbons Undergoing Bioventing at the Meso-Scale
Bibliographic record
Abstract
Bioventing can be effective for the remediation of soil contaminated with petroleum hydrocarbons. However, implementing laboratory results in field scenarios is difficult due to the lack of scale-up factors. Accordingly, laboratory bioventing experiments were undertaken at the meso-scale and then compared to previously completed micro-scale tests to evaluate the important scale-up factor. The developed meso-scale system holds 4 kg of soil, with bioventing conditions controlled from a nutrient, airflow and water content perspective. Three soils were tested, and categorised as sandy, clayey, and loam soil. Results over a thirty-day period showed a two-stage degradation pattern that encompassed first-order degradation rates as compared to the single-stage first-order degradation rate determined in the micro-scale study. For the first stage (0 to 8 d), the degradation rate for sandy soil was 0.598 d-1, with the clayey soil at 0.460 d-1, and mixed soil at 0.477 d-1. After 8 days, the degradation rate constant for the sandy soil dropped to 0.123 d-1, with the clayey soil dropping to 0.075 d-1, and the degradation rate for the mixed soil dropping to 0.093 d-1. Comparison of the measured degradation rate values with the results from the micro-scale experiments gave scale-up factors varying from 1.9 to 2.7 for the types of soil considered in the current study. These differences in degradation rates between the two scales show the importance of scale-up factors when transferring feasibility study results to the field.
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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 | 0.001 | 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 | 0.001 | 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) | 0.003 | 0.001 |
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; both teacher heads agree on what is shown here.
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".