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What are the types and characteristics of MBR membranes?Time：2021-12-31 In urban domestic sewage or large-scale sewage treatment projects, the most widely used membrane is MBR membrane. Unlike other ultrafiltration membranes, MBR membrane has excellent water quality and water treatment capacity. What are the types and characteristics of MBR membranes that we will introduce to you today? What is MBR membrane? MBR (Membrane Bio Reactor), also known as membrane bioreactor, refers to the membrane used in membrane bioreactors. Membrane products that meet the conditions for membrane bioreactor use can be called MBR membranes. There are many types of MBR membranes, including hollow fiber membranes, tubular membranes, flat membranes, and ceramic membranes. According to the installation position, they can be divided into submerged and external types. Its biggest difference lies in replacing the position of the secondary sedimentation tank with a membrane tank, while also undertaking the tasks of biochemical treatment and secondary sedimentation tank. The traditional secondary sedimentation tank settles impurities by gravity, and many other situations may occur in this process, such as sludge floating expansion, foam, etc. Membrane filtration is more thorough, making wastewater treatment more convenient. However, since they are all membranes, MBR membranes will also face the problem of membrane fouling and blockage. MBR membranes are mainly divided into two types: PVDF and PTFE. PVDF has a relatively lower price, but its anti fouling performance is worse than PTFE, and its lifespan is shorter. As for which material has a higher cost-effectiveness, it depends on the specific type and composition of the wastewater. It is highly recommended to use MBR membranes made of PTFE material for wastewater with complex components and high pollution levels, such as garbage leachate and some industrial wastewater. What are the types of MBR membranes? 1. MBR membranes can be divided into ultrafiltration membranes and microfiltration membranes based on pore size, and can be classified into hollow fiber membranes, flat membranes, and tubular membranes based on their physical form. Hollow fiber membranes are divided into curtain membranes and column membranes, as well as hollow fiber membranes with lining and hollow fiber membranes without lining. According to the usage state, it can be divided into two types: immersion type and external type. Immersion type mainly refers to hollow fiber curtain membrane and flat membrane, while external type mainly refers to tubular membrane and column type hollow fiber membrane. Column type hollow fiber membrane does not have an inner lining. 2. Due to the different properties of membrane components, MBR can be divided into internal pressure and external pressure. The direction of internal pressure water infiltration is from the inside of the membrane to the outside, while the direction of external pressure is exactly the opposite. However, in practical applications, external pressure MBR is still quite common because internal pressure MBR is prone to clogging, resulting in a decrease in membrane flux and thus reducing the treatment efficiency of MBR membranes. 3. According to the combination of membrane components and bioreactors, membrane bioreactors can be divided into three basic types: separated, integrated, and composite. What are the characteristics of MBR membrane? MBR originated from using membrane separation technology to replace the secondary sedimentation tank in activated sludge process for solid-liquid separation. This process not only effectively achieves the purpose of separating sludge and water, but also has incomparable advantages over traditional three-stage sewage treatment processes: 1. Efficiently performing solid-liquid separation, its separation effect is much better than traditional sedimentation tanks, the effluent quality is good, the suspended solids and turbidity in the effluent are close to zero, and it can be directly reused, achieving sewage resource utilization. 2. The efficient retention effect of the membrane enables microorganisms to be completely retained in the bioreactor, achieving complete separation of hydraulic retention time (HRT) and sludge age (SRT) in the reactor, and flexible and stable operation control. 3. As MBR combines the aeration tank and secondary sedimentation tank of traditional sewage treatment into one, and replaces all the process facilities of tertiary treatment, it can significantly reduce the footprint and save civil engineering investment. 4. It is conducive to the interception and reproduction of nitrifying bacteria, and the system has high nitrification efficiency. By changing the operating mode, there can also be ammonia and phosphorus removal functions. Due to the fact that the age of the mud can be very long, it greatly improves the degradation efficiency of difficult to degrade organic matter. 6. The reactor operates under high volume load, low sludge load, and long sludge age, resulting in extremely low residual sludge production. Due to the infinite sludge age, theoretically zero sludge discharge can be achieved. 7. The system implements PLC control, making operation and management convenient |
