Size of biological flocs in activated sludge systems: Influence of hydrodynamic parameters at different scales
| Autor: | Anne Goubet, Camilo Duran Quintero, Sylvain Pageot, Sylvie Gillot, Yoan Pechaud, Yannick Fayolle |
|---|---|
| Přispěvatelé: | Université Gustave Eiffel |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Process Chemistry and Technology Mixing (process engineering) Fine bubble diffusers 02 engineering and technology 010501 environmental sciences 021001 nanoscience & nanotechnology 01 natural sciences Pollution 6. Clean water law.invention Shear rate Viscosity Activated sludge Chemical engineering law Chemical Engineering (miscellaneous) [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering Aeration 0210 nano-technology Coarse bubble diffusers Waste Management and Disposal Filtration ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences |
| Zdroj: | Journal of Environmental Chemical Engineering Journal of Environmental Chemical Engineering, Elsevier, 2021, 9 (4), pp.105427. ⟨10.1016/j.jece.2021.105427⟩ |
| ISSN: | 2213-3437 |
| DOI: | 10.1016/j.jece.2021.105427⟩ |
| Popis: | In conventional activated sludge (CAS) systems and membrane bioreactors (MBR), aeration, mixing and filtration are affected by various properties of activated sludge (AS) and especially viscosity and morphological properties of flocs. The aim of the present study was to understand the relationship between hydrodynamic conditions and AS floc size properties. Floc size distribution (FSD) measurements were performed in four systems showing different hydrodynamics: (i) a standard stirred reactor (SR), (ii) a pilot bubble column (BC), (iii) a full-scale aeration zone equipped with fine bubble diffusers, (iv) a full-scale filtration zone equipped with coarse bubble diffusers. The measurements were carried out on-site, using the mixed liquor from a full-scale MBR. The FSD of the given activated sludge mainly depends on the average shear rate ( γ ) and on the circulation time in the SR. To a lesser extent, local properties, such as maximal shear rate, also influence the FSD. In the same way, the main operating parameter governing the FSD in the BC was γ . For a similar γ , the flocs were slightly larger in the BC than in the SR. In addition, in the full-scale systems, for a similar γ estimated, the FSD characteristic diameters were lower in the filtration zone (with coarse bubbles) than in the aeration zone (with fine bubbles). The FSD in the aeration zone was well correlated with the FSD in the BC whereas the flocs were slightly smaller in the filtration zone than in the BC. |
| Databáze: | OpenAIRE |
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