Membrane Bioreactor Process

Membrane Bioreactor (MBR) is a new type of sewage biological treatment device developed by Prof. Yang Zaoyan and his scientific research team after 10 years of research, the technology is called "the water treatment technology of the 21st century", the project has been listed as a national key scientific and technological research projects in the 8th -5th and 9th -5th centuries, and has been listed as a "China's 21st Century Agenda Implementation Capacity and Sustainable Development Practical New Technology", this technology is at the leading level in China, and some of the indicators have reached the international leading level.

This project has been listed as the key scientific and technological research project of China in the 8th - 5th and 9th - 5th Five-Year Plan, and has been listed as "Practical New Technology of China's 21st Century Agenda Implementation Capacity and Sustainable Development".

MBR is an efficient combination of membrane separation technology and biological treatment method, the origin of which is to replace the secondary sedimentation tank in activated sludge method with membrane separation technology for solid-liquid separation. This process not only effectively achieve the purpose of mud-water separation, but also has the advantages of sewage tertiary treatment of traditional processes are incomparable:

1, efficient solid-liquid separation, the separation effect is far better than the traditional sedimentation tank, the effluent water quality is good, the effluent of suspended solids and turbidity close to zero, can be directly reused to achieve the sewage resource utilization.

2, the high efficiency of the membrane retention effect, so that the microorganisms are completely retained in the bioreactor, to achieve the reactor hydraulic retention time (HRT) and the age of sludge (SRT) of the complete separation of the flexible and stable operation control.

3, because the MBR will be the traditional wastewater treatment of the aeration tank and two sedimentation tanks into one, and replace all the facilities of the three-stage treatment process, so it can greatly reduce the footprint, saving civil investment.

4, conducive to nitrifying bacteria retention and reproduction, the system has a high nitrification efficiency. Through the change of operation mode can also have the function of deammonia and phosphorus removal.

5, because the age of mud can be very long, thus greatly improving the degradation efficiency of difficult to degrade organic matter.

6, the reactor in the high volume load, low sludge load, long sludge age operation, residual sludge production is very low, because the age of the sludge can be infinitely long, theoretically can realize zero sludge discharge.

7, the system realizes PLC control, easy to operate and manage

Membrane Bioreactor (MBR) is a new type of water treatment technology combining membrane separation unit and biological treatment unit, replacing the secondary sedimentation tank with membrane module to maintain a high concentration of activated sludge in the bioreactor to reduce the wastewater treatment facilities to reduce the footprint and to reduce the amount of sludge by maintaining a low sludge load. Compared with the traditional biochemical water treatment technology, MBR has the following main features: high treatment efficiency, good effluent water quality; compact equipment, small footprint; easy to realize automatic control, simple operation and management. 80 years since, the technology has been more and more attention to become one of the hot spots of the research. Membrane bioreactor has been used in the United States, Germany, France and Egypt, more than ten countries, the scale from 6m3 / d to 13000m3 / d vary.

China's research on MBR is less than ten years, but the progress is very rapid. Domestic research on MBR can be broadly divided into several aspects: (1) explore the combination of different biological treatment processes and membrane separation unit form, biological reaction treatment process from activated sludge to expand to contact oxidation, biofilm method, activated sludge and biofilm combined with the composite process, two-phase anaerobic process; (2) factors affecting the treatment effect and membrane contamination, mechanism and mathematical modeling, and to explore the proper Operating conditions and process parameters, as far as possible to reduce membrane contamination, improve the treatment capacity and operational stability of the membrane module; (3) to expand the scope of application of MBR, MBR research objects from domestic wastewater to a high concentration of organic wastewater (food wastewater, beer wastewater) and difficult to degrade industrial wastewater (petrochemical wastewater, printing and dyeing wastewater, etc.), but the treatment of domestic wastewater is dominated by the treatment of wastewater.

In our country, MBR is applied to both domestic and industrial wastewater treatment research. The results of these studies have shown that MBR has achieved good results in removing COD, NH3-N, SS, turbidity, etc., in a variety of highly concentrated organic wastewater and difficult to degrade wastewater.

China's per capita water resources is only 2250m3/person. In more than 600 cities in China, there are more than 300 cities with water shortage, more than 100 cities with serious water shortage, annual water shortage of nearly 6 billion m3, annual economic losses caused by water shortage of about 200 billion yuan. The per capita water resources in North China is only 250-480m3/person per year, which is lower than the national per capita level of 1,000m3/person per year. Year, less than 1/5 of the national per capita level, almost all cities in this region are facing water shortage. Therefore, wastewater reuse is one of the important measures to alleviate the water crisis in North China Plain. Membrane bioreactor technology has attracted much attention because of its high quality effluent, which is considered to be a water-saving technology with better economic, social and environmental benefits. Although there is still the problem of higher operating costs, the investment in MBR will be reduced with the advancement of membrane manufacturing technology, the improvement of membrane quality and the reduction of membrane manufacturing costs. Such as polyethylene hollow fiber membranes, the development of new ceramic membranes and so on has led to a significant reduction in its cost than in the past. On the other hand, the development of a variety of new membrane bioreactors also make the true operating costs are greatly reduced, such as gravity-flooded MBR, anaerobic MBR operating at low pressure and the traditional aerobic pressurized membrane bioreactor compared to its operating costs decreased substantially. Therefore, from a long-term point of view, the membrane bioreactor in water treatment applications will become more and more extensive. In today's increasingly stringent environmental standards in the water, MBR has shown its great potential for development, will be the new century to replace the traditional wastewater treatment technology is a strong contender.