Spectrometric analysis of the metabolism and adsorption of naphthenic acid fraction compounds in a phytoremediation treatment system
Bibliographic record
Abstract
Bitumen mining in northern Alberta produces large volumes of oil sands process-affected water (OSPW) that require treatment before being released into the environment. Naphthenic acid fraction compounds (NAFCs) are considered primary contributors to OSPW toxicity; therefore, remediation efforts often target these compounds. Phytoremediation is proposed as a feasible treatment for OSPW using a constructed wetland treatment system (CWTS) strategy due to the cost-effective and low-maintenance nature of this technology. A CWTS uses plants and their associated microorganisms to take advantage of natural metabolic processes for the uptake and biotransformation of environmental contaminants. While CWTSs for OSPW treatment have demonstrated success in attenuating NAFCs and reducing toxicity in mesocosm and pilot-scale studies, the fate of NAFCs in a CWTS is not well understood. This thesis research aimed to gain insight into NAFC fate in CWTSs by exploring NAFC biotransformation processes in plant tissues and the adsorption characteristics of NAFCs onto sediment substrates. A method for extracting NAFCs and their metabolites from plant tissues was developed and used to extract the isotopically labelled model compound 1-adamantanecarboxylic acid (¹³C-AdCA) and NAFCs from OSPW. This method, in combination with high-resolution Orbitrap mass spectrometry, was used to track the uptake, translocation, and biotransformation within plant roots and shoots. These experiments showed a general decrease in compound abundance over time, indicative of transformation events. The OSPW treatments further demonstrated that the majority of NAFCs were completely transformed in root and shoot tissues. Additionally, incubation studies were conducted to test parameters associated with NAFC adsorption onto various sediments. The adsorption of NAFCs from OSPW onto a sediment substrate from the oil sands region appeared to be impacted by the properties of the OSPW itself, including NAFC concentration, class differences, or shifts in carbon number and double bond equivalents. Other factors, such as water quality characteristics, may also impact adsorption. Overall, the results of this research provide insight into the fate of NAFCs in phytoremediation systems, guiding future metabolomics studies and considerations for the large-scale implementation of plant-based technologies in OSPW treatment strategies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".