The main types of biofilm processing systems 1. Biofilter: Construction: filter bed, pool body, water distribution equipment (in order to make the sewage evenly distributed on the surface of the whole filter bed) and drainage system (collecting the sewage and biofilm from the filter bed to ensure ventilation and support the filter material). characteristic: 1) can provide a large area for microbial attachment; 2) flowing the sewage through the biofilm in a liquid film state; 3) There is sufficient void ratio to ensure ventilation (ie to ensure the supply of oxygen) and to allow the shed biofilm to flow out of the filter with water; 4) It is not decomposed by microorganisms, does not inhibit the growth of microorganisms, and has good chemical properties; 5) have a certain mechanical strength; 6) The price is low. The main advantage is that it is easy to operate and therefore suitable for small towns and remote areas. Process: consists of primary sedimentation tank, biological filter tank and secondary sedimentation tank. 2. Biological turntable: Structure: There are a series of parallel rotating discs, rotating central shaft, power and speed reduction device, oxidation Cao and so on. Mechanism: When working, the wastewater flows through the water tank, the motor rotates the turntable, and the biofilm and the atmosphere are in contact with the waste water. When immersed, the organic matter in the waste water is adsorbed, and when exposed, the oxygen in the atmosphere is absorbed. The rotation of the turntable brings in air, and causes turbulence in the water in the water tank to evenly distribute dissolved oxygen. As the membrane thickens, the microorganisms in the inner layer are in an anaerobic state, and when the activity is lost, the biofilm is detached and flows along with the effluent to the secondary sedimentation tank. characteristic: 1) No need for aeration and recirculation, low power consumption and low cost during operation; 2) The operation management is simple and the technical requirements are not high; 3) Stable work and strong adaptability; 4) Adapt to sewage of different concentrations and different water quality; 5) The amount of excess sludge is small, and it is easy to precipitate and dewater; 6) There are no problems such as filter flies, foul odor, blockage, foam, noise, etc.; 7) Multi-layer three-dimensional arrangement; 8) Generally, it is necessary to add protection and insulation for the hole protection cover. Arrangement: single-axis single-stage, single-axis multi-stage and multi-axis multi-stage 3. Biological contact oxidation: Structure: mainly composed of pool body, packing and water inlet and outlet devices characteristic: 1) has a high microbial concentration, generally up to 10~20g/L; 2) The biofilm has a rich biological phase, contains a large number of filamentous bacteria, forms a stable ecosystem, and has low sludge yield; 3) has a high oxygen utilization rate; 4) has strong impact load resistance; 5) high biofilm activity; 6) There is no problem with sludge expansion. 7) Disadvantages: The filter bed is easy to block and replace, and the running cost is high. 4. Biological fluidized bed: mechanism: 1) Fixed bed stage: When the liquid flows through the bed at a small speed, the solid particles are in a stationary state, and the height of the bed is basically maintained. At this time, the bed is called a fixed bed. 2) Fluidized bed stage: When the liquid flow rate is greater than the flow rate at point b, the bed is no longer maintained in a fixed state, the particles are suspended by the liquid and suspended, and flow in all directions of the bed, and there is a horizontal interface in the upper part of the bed. At this time, the bed formed by the particles is completely in a fluidized state, and such a bed is called a fluidized bed. 3) Liquid transport stage: When the liquid flow rate increases beyond c point, the bed no longer maintains fluidization, the interface at the upper part of the bed disappears, and the carrier is taken out from the fluidized bed with the liquid. This stage is called the liquid transport stage. In a water treatment process, such beds are referred to as "moving beds" or "flow beds." Type: Two-phase biological fluidized bed and three-phase biological fluidized bed characteristic: Advantages: The filter bed has a large surface area, high volumetric load, strong impact load resistance, strong microbial activity, and good mass transfer effect. Disadvantages: the wear of the equipment is more serious than that of the fixed bed, and the carrier particles will be worn down during the turbulent process; there are problems in production amplification when designing: anti-blocking, aeration method, selection of influent water distribution system, bio-particle loss . For more information, please pay attention: Yingnuo Instrument (Shanghai) Co., Ltd. Website: http:// The company's main products are BOD differential pressure measuring instrument developed by American Anno Laboratory, solid waste toxicity leaching equipment (TCLP), hand-held oil measuring instrument (OILTECH121), BOD online analyzer. 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