Xử lý nước thải bằng công nghệ sinh học, chương 1

MBR (Membrane Brio-Reactor) can be broadly defined as systems integrating biological degradation of waste products with membrane filtration. Set up of MBR plant is mainly utilizing a bioreactor and membrane filtration as one unit process for wastewater treatment thereby replacing, and in some cases supplementing, the solids separation function of secondary clarification and effluent filtration, resulting the possibility to eliminate the secondary clarification and operate at higher MLSS concentration....
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Xử lý nước thải bằng công nghệ sinh học, chương 1 SYSTEM DESIGN & OPERATION MANUALMembrane Bioreactor (MBR) SystemMembrane Bioreacotr Operation & Maintenance GuidelineMBR IntroductionMBR (Membrane Brio-Reactor) can be broadly defined as systems integrating biologicaldegradation of waste products with membrane filtration.Set up of MBR plant is mainly utilizing a bioreactor and membrane filtration as one unit processfor wastewater treatment thereby replacing, and in some cases supplementing, the solidsseparation function of secondary clarification and effluent filtration, resulting the possibility toeliminate the secondary clarification and operate at higher MLSS concentration.In summary, the MBR system is the combination of traditional Actitived Sludge Treatment with themembrane technology. The design criteria of the system shall be base according to the traditionalway of Activated Sludge Treatment principle. However, on top of that, the MBR modules areimmersed and located in the air blow tank/ aeration basin (biological reactor tank), the clear wateris pumped(sucked) out from the MBR modules. This shall possibly eliminate the needs ofsecondary clarifier.Advantages of the MBR: • Better control of biological activity • Effluent that is free of bacteria and pathogens • Smaller plant size • Biodegradation efficiency enhanced 10%~30% • Short Hydraulic Residence Time (HRT) & Long Sludge Residence Time (SRT) • Activated sludge increase by 2~3 times • No secondary settling and disinfecting tank required • Higher organic loading ratesTypical Applications • Living wastewater treatment, medical water treatment and reuse (residential area, hotel etc.) • Food industry wastewater (bean factory, cake factory etc.) • Beverage industry wastewater • Agricultural waster • Waster water of pharmaceutical • Zoology toiletWorking principle: • 3 pcs. of membrane modules are connected parallely through the header of the module to form a cassette (frame). It is then connected the suction side of a permeate pump, the membranes are subjected to a slight negative pressure (suction pressure). • In an “outside-in” process operation, water is drawn from the mixed liquor through the membrane module and into the capillary, further enhanced by suction effect of pump. From there, the treated water is drawn through the header and out through the discharge system. • On a continuous basis, air diffusion at the bottom of the membrane modules, where it emerges as a coarse/ fine bubble stream. This air stream performs the triple role of process aeration, mixing of the biomass and membrane cleaning. • Also, with the continuous movement of air bubbles around and through the fibers, a lower concentration of biomass is maintained around the membranes and this, in turn, minimizes the potential for membrane fouling. • The membrane modules/ cassette are modular design and can be dismantled individually for manual cleaning as part of supplementary periodic maintenance.Specification - Model MBR-1000 • Material : Polypropylene • Type : Hollow Fiber • Capillary Thickness : 40 ~ 50 µm • Capillary Outer Diameter : 450 µm • Capillary Pore Diameter : 0.01 ~ 0.2 µm • 7.0 x 10-2 cm3/cm2 • S • cmHg Ventilation Rate : • Porosity : 40 ~ 50% • Lengthways strength : 120,000 kPa • 6 ~ 9 L/M2/H Designed flux : • 8 m2/module Area of membrane module : • Operating Pressure : -0.01 ~ -0.03 MPa • Abnormal Pressure : > -0.05 kpa • 1.0 ~ 1.2 m3/ day Flow-rate :Parameters of installation • Material of installation frame: UPVC or A3 steel with antirust • Connection pipe: PPR pipe, galvanize pipe or high strength tube • Space between MBR unites: 80-100mm • Space between installation frame and the wall of reactor: ≥400mm • Space between installation frames: ≥500mmSizing • Treatment Flowrate, m3/hr = Tank Volume, m3 / HRT, hr • Module required = Treatment Flowrate, m3/day / (1 m3/day) Application Suggested HRT Sewerage treatment/ recycle 4 ~ 6 hr Wastewater treatment in food industry 10 ~ 20 hr Wastewater treatment in breed aquatics industry 10 ~ 20 hr Wastewater treatment in chemical industry 24 ~ 48 hrSuggested Influent Requirement/ Limitation Granular ≤ 50 µm Turbidity ≤ 20 NTU pH 1~14 Temperature 4~40ºC Operating Vacuum Pressure -0.01 ~ -0.03 MPaInstallation & Operation • 3 pcs. of membrane modules are connected parallely through the header of the module to form a cassette (frame). It is then connected the suction side of a permeate pump, the membranes are subjected to a slight negative pressure of -0.01 to -0.03 MPa (1.5 to 4.5 psi). (refer Diagram in “Module Assembly Arrangement”) • In an “outside-in” process operation, water is drawn from the mixed liquor through the membrane module and into the capillary, further enhanced by suction effect of pum ...