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Record W4407230023 · doi:10.1016/j.envadv.2025.100619

Assessing the effect of deposited bitumen or asphaltenes on the nitrification process in the north saskatchewan river sediment

2025· article· en· W4407230023 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.
aboutThe title or abstract carries a Canadian signal from the geographic lexicon.

Bibliographic record

VenueEnvironmental Advances · 2025
Typearticle
Languageen
FieldEnvironmental Science
TopicMicrobial bioremediation and biosurfactants
Canadian institutionsDevon Energy (Canada)Natural Resources Canada
FundersNatural Resources Canada
KeywordsAsphalteneAsphaltSedimentNitrificationEnvironmental scienceOil sandsEnvironmental engineeringEnvironmental chemistryGeologyNitrogenGeographyChemistryGeomorphologyArchaeology

Abstract

fetched live from OpenAlex

Following oil spills, heavier compounds of oils formed oil-sediment mixtures and deposited on the riverbed, yet their impacts on freshwater sediment ecosystems are not well understood. This study aimed to (1) examine the effects of deposited bitumen (Bit) and asphaltene (Asp) on the North Saskatchewan River (NSR) water quality, focusing on organic carbon and nitrogen; (2) assess the impact of Bit or Asp on sedimentary nitrification; and (3) explore the response of the microbial community to Bit or Asp. Laboratory-scale abiotic (no sediment) and biotic treatments with fresh (NH₃-deprived) sediment and NH₃-enriched sediment were performed at 20 ± 1°C for up to 120 days. Results of the abiotic and biotic treatments with fresh sediment indicated that up to 5 mg/L of total organic carbon (TOC) or nitrogen in the form of NH 3 leached from both deposited Asp and Bit into the overlaying water. Considering the relatively low background concentrations of TOC (2.19 ± 0.29 mg/L) and nitrogen (0.07 ± 0.02 mg/L) in the NSR water, the leached compounds could contribute to the overall organic carbon and nitrogen concentrations in the river. A comparison of the unexposed NH 3 -enriched sediment (Ctl) and Bit-exposed NH 3 -enriched sediment showed that exposure of nitrifying communities did not affect ammonia oxidation but decreased nitrite (50 %) and nitrate (30 %) production. Additionally, the sedimentary microbial community composition altered from its initial composition to a new profile post-exposure to Asp or Bit. The microbial communities also responded differently to Bit exposure compared to Asp exposure. For instance, Asp-exposed sediment was dominated by a diverse group of taxa, while Bit-exposed sediment was mainly dominated by phylum Proteobacteria post-exposure. Overall, the findings indicate that deposited Bit and Asp could contribute organic carbon and nitrogen to the NSR water, impaire the sedimentary nitrification process and alter microbial community composition in the sediments.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.145
Threshold uncertainty score0.254

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.006
GPT teacher head0.254
Teacher spread0.248 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it