Applications of the membrane bioreactor (MBR) method

Application areas of membrane bioreactors: Water treatment in hospitals, office buildings, residential complexes, urban areas, hotels, restaurants, airports, stations, large public buildings, and bathing facilities. Treatment of high-concentration industrial wastewater from various industries such as food processing, fermentation, livestock farming, printing and dyeing, pesticides, textiles, oil refining, and construction chemicals. The treated water can be used for a wide range of purposes, including car washing, toilet flushing, landscaping, air conditioning system refilling, landscape irrigation, fire fighting, etc.; it can also be reused in some industrial processes. Nature and principle of membrane bioreactors: The MBR process is a new type of biological wastewater treatment technology that combines modern membrane separation techniques with biotechnology. It uses membrane separation devices to effectively retain activated sludge and large molecular organic substances in the biochemical reaction tank, thereby replacing the secondary sedimentation tank and increasing the concentration (biomass) of activated sludge in the biochemical reaction tank； Separate control of hydraulic retention time (HRT) and sludge retention time (SRT) is achieved, allowing difficult-to-degrade macromolecular organic substances to remain in the reaction tank where they continue to react and degrade. Therefore, the membrane-biological reactor process enhances the treatment efficiency of biological reactors through membrane separation technology. Compared with traditional biological treatment processes, it offers advantages such as high biochemical efficiency, strong resistance to load fluctuations, good and stable effluent quality, small land area required, long sludge discharge intervals, and ease of automatic control. It is one of the most promising biological wastewater treatment technologies currently used in areas such as the treatment of high-concentration organic wastewater and reclaimed water reuse. Features of membrane bioreactor systems for treating domestic wastewater: 1. The treatment process is simpler, with a smaller size; the primary sedimentation tank used in traditional processes is eliminated, and the aeration tank and secondary sedimentation tank are combined into one unit, thereby replacing all the equipment required in three-stage treatment processes and reducing construction costs. 2. The quality of the treated water is high, meeting the standards set by the Ministry of Construction in its “Standards for Quality of Domestic Wastewater” (CJ25.189). 3. The operating pressure is low, which helps save energy. 4. The membrane components can last around 3 years, and their cleaning and replacement are easier. 5. Control is straightforward, operating costs are low, and the level of automation is high. 6. The hydraulic retention time is short, while the sludge retention time is long. 7. The microbial concentration is 2–3 times higher than that in traditional activated sludge processes, resulting in higher biochemical efficiency, less excess sludge, and longer intervals between sludge removals. 8. It is capable of treating wastewater with high concentrations of NH-N. Some information found previously