Reclamation of Unconventional Oil Processed Water through the Adsorption of Naphthenic Acids by Carbon Xerogel
Notice bibliographique
Résumé
This study examines the use of carbon xerogel (CX) material for the adsorption of naphthenic acids (NAs). The adsorption of NAs is crucial for the reclamation of unconventional oil processed water, more specifically Alberta’s oil sands process-affected water (OSPW). CX material is synthesized at specific operating pH conditions to result in a material that exhibits an extensive mesoporous character. Therefore, the employment of CX as an adsorbent can not only promote the adsorption of a wider range of complex NAs present in OSPW, but can also be synthesized to provide textural characteristics that adhere to contaminants present in all forms of unconventional oil processed water. This thesis begins with a review of the fundamentals of the adsorption phenomena, then provides a comprehensive analysis of Alberta’s OSPW with an elaborate description of the characteristics of NAs present in OSPW. Furthermore, the various treatment technologies that have been studied to treat OSPW from NAs is discussed with special focus on adsorption processes. The evaluation of the adsorbents discussed in this section reveals that their performance is restricted given that they are derived from raw materials, which accordingly limits their textural properties. As a result, the utilization of synthesized CX is necessary to enhance the removal of NAs form OSPW through adsorption. As a preliminary investigation of CX to treat OSPW, identifying the adsorption mechanisms responsible for the removal of NAs is initially required to further enhance the performance of CX in actual OSPW. Therefore, this study focusses on examining the efficacy of CX in terms of adsorbing model NA compounds; more specifically, heptanoic acid (HPA), 5-cyclohexanepentanoic acid (CHPA), and 5-Phenylvaleric acid (PVA). All three model NAs contain a carboxylic acid and long chain structure, with exception to CHPA which contains an additional cyclic ring, and PVA contains an aromatic ring. Therefore, by exploring the adsorption of these three model compounds, at pH 8, onto CX, the structure-activity relations responsible for adsorption are deduced. Furthermore, HPA, the simplest compound among the three, is examined in focus at three pH conditions, pH 8, 6.5, and 5, which are above, near, and below the pH of point zero charge for CX, 6.8. Therefore, the electrostatic interactions responsible for the adsorption of NAs onto CX can be identified. Note that at all conditions, similar investigations were conducted with granular activated carbon (GAC) to evaluate the effectiveness of CX relative to the conventional adsorbent used for the removal of NAs form OSPW. Moreover, the results were analyzed per adsorbent capacity, the internal diffusion model, and adsorption rate models; pseudo-first order and pseudo-second order, to demonstrate that CX performs exceptionally well relative to GAC due to its mesoporous structure. More specifically, the results have revealed that PVA, the more complex NA is adsorbed more easily by CX due to π-π interactions, followed by HPA due to its surfactant-like structure, and finally CHPA is adsorbed least due to its high molecular weight which delays its kinetics. The role of hydrophobic-hydrophobic forces has been noted during the diffusion of the three model NAs into the stagnant film surrounding the CX surface, and the hydrophobic bonding may be recognized as negatively charged assisted hydrogen bonding (-CAHB). In terms of HPA, van der Waals attractive forces, in the form of dipole-dipole attractions, have been recognized as the probable electrostatic mechanism responsible for the stronger attraction of HPA onto CX.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».