Decontamination of Automobile Workshop Soils containing Heavy Metals and PAHs using Chelating Agents
Bibliographic record
Abstract
Automobile repair workshops are major anthropological sources of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in Nigerian cities. The extent of contamination of soil from workshops in Ibadan city was evaluated by contamination or pollution index (C/P index) assessment. The C/P index assessment indicated that the soils were categorized from moderately contaminated to severely polluted class with Pb, Cd, Cr, Zn and Mn. The concentration of 16 PAHs in the soil samples ranging from 24521 to 2340025 g/kg were far above the levels in the control samples. Washing of soil from different automobile repair workshops using ethtylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and ethanol was investigated. Since mixed contaminants are usually co-existing in the environment, additional experiments involving a combined solution were conducted to remove both PAHs and heavy metals. The results indicated that the removal efficiencies of the extractants were in the order 0.1M DTPA > 0.1M EDTA > 0.01M DTPA > 0.01M EDTA for the heavy metals removal. However, the combined extractants of EDTA and ethanol had much higher PAHs removal efficiency than ethanol alone. The use of mixed extractants was more effective for PAHs and had very little effect for the removal of heavy metals, especially zinc.
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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".