Évolution biochimique des résidus de désencrage dans un contexte de valorisation comme barrière de recouvrement
Notice bibliographique
Résumé
Deinking residues (DR) are produced in the first steps of paper recycling. Most of the Quebec's production, approximately 500 000 humid tons per year, is still sent to dedicated landfills. However, new DR valorization approaches have been proposed, such as their use as geotechnical replacement material for fine-textured soil in the construction of cover systems for landfills or tailings that generate acid mine drainage (AMD). Due to the high organic content of DR, biochemical and chemical evolution (degradation) can take place and impact not only the environment that they aim to protect, but also the geotechnical properties of DR. In this context, the purpose of this study was to understand DR degradation mechanisms, evaluate their long-term state, and appraise the impact of degradation on the behaviour of DR in the laboratory and in the field. To attain this goal, this study was divided into three steps: (1st) DR characterization; (2nd) laboratory degradation tests; and (3rd) evaluation of DR degradation in the field. According to tests carried out, it is possible to state that DR degradation follows the degradation phases of domestic waste in sanitary landfills, from the point of view of biogas production evolution as well as the quality of leachate parameters. After 400 days of tests under controlled conditions, a total mass loss of approximately 16% was obtained for the tests at 38 [degrés Celcius] and 21 [degrés Celcius]. The loss for a test at 12 [degrés Celcius] was approximately 10%. In the case of the tests at 38 [degrés Celcius], the mass loss by gas production became greater than that by leaching. Microbiology studies identified bacilli and fluorescent sarcina as the predominant morphologies, although they were not as numerous compared to what can be found in domestic wastes. Based solely on observations with the naked eye or with a low-level magnification electronic microscope, it isn't possible to observe a noticeable change in DR appearance, structure and morphology. However, with stronger magnification, we observe areas with significant alteration, accompanied by high microorganism density. Geotechnical tests and monitoring of certain geomechanical and hydraulic parameters show that: degradation caused an increase in water content; degradation affects DR compressibility and causes a decrease in hydraulic conductivity. With loading, DR undergoes significant volume variations (creep), which are potentialized by degradation. Field results demonstrate that several follow-up parameters evolved very similarly in the case of barriers installed at the Eustis and Clinton mine tailings, notably biogas composition ([approximate] 40% CH[subscript 4] and [approximate] 50% CO[subscript 2]) and the quality of leachate collected (concentration in total solids around 25 g/l). However, mass loss by leaching is slow, due to low infiltration speeds (evaluated based on water collected in lysimeters). According to the results obtained and observations made during this study, the relevant properties of DR do not seem to be negatively affected by the degradation level attained in the laboratory.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| 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 | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 source (Gemma direct ou Codex distillé), 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 ».