High-Rate Vacuum-Enhanced anaerobic Digestion: Performance, ammonia recovery and process kinetics
Bibliographic record
Abstract
This study investigated the applicability of side-stream vacuum for intensification of anaerobic digestion (AD) at organic loading rates (OLRs) of 3.8–4.5 kgVS/m 3 /d (6.1–7.3 kgCOD/m 3 /d), and ammonia recovery at four times the OLR of a conventional AD. Initial operation showed a performance decline due to Methanosaeta dominance and its inability to resist vacuum, resulting in low methane yield (0.06 L/gCOD feed , 15 % COD destruction) and high SCOD accumulation (12 g/L). Methanosarcinaceae enrichment under vacuum restored stability, achieving 49 %–53 % VSS destruction. Ammonia inhibition was mitigated by 44 %–47 % TKN recovery through ex-situ vacuum stripping, maintaining ammonia concentrations below 1 gN/L, compared to a potential inhibitory level of > 4 gN/L without ex-situ vacuum. The dominance of Methanosarcinaceae and successful ammonia recovery corresponded with stable operation at four times the OLR of conventional digesters. Biokinetic studies revealed a 155 %–232 % improvement in biomass-specific acetoclastic methanogenic activity through ex-situ vacuum. Fluorescence excitation-emission matrix-parallel factor analysis showed accumulation of the slowly biodegradable fluorescing organic. High fermentative bacterial counts were maintained, with increased populations of DMER64 , Mesotoga , Synergistaceae , Clostridium_sensu_stricto_1 , Pelotomaculum, and Syntrophomonas , suggesting resistance to vacuum stress, while Smithella decreased.
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.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| Science and technology studies | 0.000 | 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) | 0.000 | 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 teacher head, 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".