Enhanced Primary Sludge Fermentation and Anaerobic Digestion for Integrated Carbon Upgrade and Resource Recovery
Notice bibliographique
Résumé
The emerging paradigm shift towards renewable resource recovery, and energy minimization in municipal wastewater treatment plants (WWTPs) coupled with increased concern over nutrients-related eutrophication accelerated the development of biosolids treatment technologies for simultaneous waste minimization, resource recovery, and carbon upgrade. Biological nutrient removal (BNR) processes, often need excess carbon source to meet stringent quality standards. Despite successful use of sludge fermentation liquid to enhance the BNR, different techniques, are applied to improve the low conversion yield of fermentation and optimize resource recovery. In this context, insights on the impact of two commonly used primary treatment techniques (i.e. conventional primary clarifier and the emerging rotating belt filtration (RBF) technology) on the single and integrated anaerobic fermentation and digestion of wastewater biosolids was investigated in this study. Techno-economic assessment and optimization to simultaneously maximize volatile fatty acids (VFAs), and biomethane recoveries, and further application of internal carbon source to enhance the BNR process using a plant-wide approach, were also among the main objectives of this project.\nThe fate of cellulose study revealed that roughly 80% of the raw wastewater cellulose was removed in either of the primary treatment options, while represented 35%, and 17% of the total suspended solids (TSS) in the RBF and primary clarifier sludges, respectively. Cellulose was biodegradable irrespective of the biological process configuration and tested Solids retention times (SRTs), with effluent concentrations of about 2-3 mg/L.\npH-controlled fermentation was effective in improving the VFA yields by up to 93% and 72% at pH 9, for RBF and primary sludges, respectively. Furthermore, pH 6 was proposed as optimum considering significant enhancement in VFA production, while also lowering the amount of consumed chemicals. Interrelated impact of enzyme, temperature, and SRT on the enhancement of primary and RBF sludges fermentation showed a positive impact of enzyme dose as well as temperature and SRT on the VFA and soluble COD production. Cellulase increased the VFA yields by up to 36% and 86% for primary and RBF sludges, respectively. Response surface methodology (RSM) model depicted the existence of an optimum in the high-enzyme (1%-1.5%), long-SRT (3d-4d) range. The economic viability of fermentation at full scale was confirmed by proving that VFA recovery could save up to 7.2±2.0% (RBF), and 7.6±2.7% (PS) of the overall sludge disposal costs. Integration of fermentation and anaerobic digestion negatively impacted the biogas production of the residual fermented solids by 8.4% and 12.7%, compared to fresh primary and RBF sludges due to the VFA recovery, respectively; but still economically outperformed the single stage digestion under all tested scenarios.\nBoth primary and RBF sludge fermented liquid (SFL) were effective in enhancing BNR. Removal efficiencies in the rectors were reached up to 57% (total nitrogen) and 92% (total phosphorus), upon supplementation with the SFL. Effluent nitrogen and phosphorus of the reactors were closely matched for the two trains in the range of 15± 6 mg N/L, and 0.5 ± 0.3 mg P/L, respectively. A case study incorporating experimental results into a plant-wide model showed a moderate (3.4%-8.5%) improvement in the effective COD:N and COD:P ratios (compared to the original feed); but a significant increase in readily biodegradable (rbCOD) and VFAs (2.5-6.1 times) in the combined feed could be achieved by utilization of fermeners.
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 | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| 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 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 ».