Use of immobilized zinc oxide photocatalysts for wastewater treatment: Application to methylene blue degradation
Bibliographic record
Abstract
Abstract Zinc‐oxide (ZnO) nanoparticles were immobilized on borosilicate glass spheres with treatment of zinc acetate dihydrate (ZAC) solution, and calcination at 400–450°C. The isotherm and kinetic parameters of methylene blue (MB) sorption on ZnO‐coated glass beads were estimated from batch sorption tests in darkness. An ultraviolet (UV)‐lamp with nominal power of 6 W and emission peak at 375 nm was used as a light source. Batch experiments of MB photodegradation were performed in a double‐wall glass reactor. Continuous flow tests were conducted in a poly(methyl methacrylate) (PMMA) annular photoreactor by recirculating the MB solution between it and a feed tank. All results were interpreted with dynamic models based on a two‐step process consisting of MB adsorption/desorption, and adsorbed MB surface reaction. The intense stirring caused by air bubbling or aqueous phase flow triggers the detachment of catalyst mass from substrate, the partial renewal of immobilized catalyst surface exposed to UV‐radiation, and the enhancement of the apparent maximum MB sorption capacity by total ZnO mass. The fast MB adsorption leads to an almost constant concentration of adsorbed MB at equilibrium, while the surface photocatalytic reaction is the MB degradation rate‐controlling step. Comparable values of the kinetic constant of surface reaction are estimated from batch and continuous flow tests, for repeated cycles of photocatalysis.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".