Impact of chemical oxidation on sludge properties and membrane flux in membrane separation bioreactors
Bibliographic record
Abstract
Abstract The effects of sodium hypochlorite (NaOCl) on sludge properties and membrane permeate flux were studied using a pressurized stirred ultrafiltration cell. Oxidation with NaOCl resulted in sludge solubilization and decreased sludge floc sizes. The sludge dissolution constant was estimated at 0.3 ± 0.1 mg sludge mg −1 free chlorine under testing conditions. The increases in soluble chemical oxygen demand and total carbohydrate concentration in centrifuged supernatant were less than proportional to chemical dosage. Membrane permeate fluxes were much lower as a result of oxidation. Soluble biopolymers accounted for more than 76% of the total hydraulic resistance during ultrafiltration of oxidized sludge. By contrast, both the settleable sludge flocs and the soluble biopolymers were important contributors to the hydraulic resistance of sludge before oxidation. Given the benefits of NaOCl solution for membrane cleaning and its negative impact on sludge properties, the quantity of NaOCl solution used for maintenance cleaning of membranes should be optimized. Copyright © 2004 Society of Chemical Industry
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.001 |
| 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".