With the progress of modern industry and rapid population growth, the problem of water pollution has become one of the focuses of society. Current sewage treatment methods mainly include activated sludge method and biofilm method. There are two types of membrane methods: the activated sludge method was established in the UK in the early 20th century. After decades of development and innovation, it has multiple operating modes. At the same time, due to its excellent sewage treatment effect, it has gradually matured. Treatment; The biofilm method is a process of purifying water bodies using organisms attached to fillers. In recent years, water bodies have also been rapidly developed and improved.
Judging from years of operation practice, the activated sludge method is relatively mature, but it also has many shortcomings and deficiencies, such as a large volume of aeration tank, a large area, and high capital construction costs. 3. The adaptability of water quantity change is low, and the water quality and water quantity change easily affect the operation effect. In view of the above factors, this sewage treatment method was gradually replaced by the later biofilm method. The biofilm method makes up for many shortcomings of the activated sludge method, such as good stability, strong ability to withstand organic and hydraulic loads, no sludge expansion, no backflow, high organic removal rate and small reactor volume, and sewage treatment plant footprint Small area and other advantages. However, the biofilm method also has its own unique drawbacks. For example, the filter material in the biofilter is easily clogged and requires regular backwashing. At the same time, it is more difficult to fix the filler and replace the aeration equipment under the filler. , And the carrier particles in the biological fluidized bed reactor can only function in a fluidized state, and the stability of the process is very poor … etc. Between the shortcomings and shortcomings of the above two processes, a moving bed biofilm-reactor (MBBR) came into being. The MBBR method was introduced in the late 1980s and quickly applied in Europe. It absorbs the advantages of traditional activated sludge method and biological contact oxidation method and becomes a new and efficient composite process treatment method. The core part is to directly add the suspended filler whose specific gravity is close to water as the active carrier of microorganisms to the aeration tank. It depends on the aeration in the aeration tank and the lifting effect of the water flow in the flow state. When the microorganisms are attached to the carrier, with the continuous rotation of the mixed solution, the floating carrier moves freely in the reactor, thereby achieving the purpose of sewage treatment. The combination of the suspended growth activated sludge method and the attached growth biofilm method in the MBBR method has the following two advantages in the process: small footprint-only 20% of the volume of an ordinary oxidation tank under the same load conditions; The carrier flows with the water flow, so there is no need to return or recycle the activated sludge; Carrying organisms continue to fall off to avoid blockage; High organic load, strong impact load resistance, and stable effluent quality. Low head loss, low power consumption, simple operation, easy operation and management; also suitable for decoration projects.
In the past ten years of research, the MBBR method has been widely used as a mature process in papermaking wastewater, food industry wastewater, slaughter wastewater, oil refining wastewater, and other industrial wastewater. It can also treat urban domestic wastewater and industrial wastewater and mixed wastewater . Many engineering examples show that the MBBR method is very useful for sewage treatment.