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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 49651 (06)
- University: Sharif University of Technology
- Department: Chemical and Petroleum Engineering
- Advisor(s): Shaygan, Jallaledin; Hazrati, Hossein
- Abstract:
- Membrane bioreactors (MBRs) are a combination of activated sludg and mebrane technology. MBRs have been widely used as an advanced process for urban and industrial wastewater-treatment in recent years. Membrane fouling is the main issue that limits their performance and therefor, many studies have concentrated on testing different ways to mitigate the fouling. Ozonation process, that has been proved to reduce the MBR fouling, is studied in this project. Ozonation can provide the conditions for flocculation and therefor improves mixed-liqure properties. Ozon at two concentrations, 0.2 and 0.9 mg/lit was tested. Although results show little change in COD (chemical oxygen demand), but membrane fouling remarkably decreases which can be due to viscosity-reduction after ozonation, reduction in main fouling factors including EPS and SMP and also increase in floc size. At 0.2 concentration, SMP shows little changes but EPS decreases. At 0.9 mg/lit of ozon, MLSS and MLVSS show reduction. Besides, results show that protein content in EPS and SMP decreases but polysaccharide content does not change. Moreover, EEM analyses and EPS tests on cake layer are in good agreement and prove that protein which is an important fouling factor, reduces after ozonation. The test on size distibution of slug for both reators showed that particles size in MBR increase by 20% with ozonation. Finally, Microscopic observations express a reduction in filamentous bacteria after ozonation. These results together with TMP reduction prove the positive effect of ozonation on mitigating membrane fouling improvement of sludg properties
- Keywords:
- Membrane Bioreactor ; Membrane Fouling ; Decline Fouling ; Ozonation ; Sludge Properties
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