Aeration is an important process in the aerobic biological treatment system of sewage. Generally, air is artificially introduced into the biochemical aeration tank through appropriate equipment to achieve the intended purpose. The aeration not only makes the liquid in the pool contact with the air for oxygenation, but also agitates the liquid, which accelerates the transfer of oxygen in the air to the liquid, thereby completing the purpose of oxygenation. In addition, the aeration also prevents the suspension in the pool from sinking and strengthens the organic matter in the pool. The purpose of contact with microorganisms and dissolved oxygen, so as to ensure that the microorganisms in the pond under the conditions of sufficient dissolved oxygen, the oxidative decomposition of organic matter in sewage. The aeration effect greatly affects the efficiency of the biological treatment system. At the same time, aeration is a very energy-consuming process. In general, the energy consumption of aeration accounts for 60% -80% of the energy consumption of the entire processing system. The quality of the aeration device not only affects the biochemical treatment of sewage, but also directly affects the land occupation of the treatment site. Product name Use Advantages Disadvantages Corundum aerators A / O, A2 / 2 Applicable media: Industrial or urban sewage with more complex mediators The resistance loss rises faster, the oxygen utilization rate is general, and it is easy to scale; the system needs to be equipped with a cleaning and drainage device diaphragm disk Type aerators A / O, A2 / 2 are arranged uniformly. The utilization ratio of oxygen is high. After 3 to 6 months of operation, the resistance loss is more than 600? Water column, which needs to be cleaned in time (pickling); Type aerators A / O, A2 / 2, SBR, and CAST are arranged uniformly. The oxygen utilization rate is high, and the reliability is good. Timely cleaning (pickling) is required. The system needs to be equipped with a blowdown device. , A2 / 2, SBR, CASTa. Low comprehensive cost b. High oxygen utilization rate c. Can be operated intermittently without blocking the initial resistance loss is 100 ～ 200? Higher than that of disc aerator. Market status of water column aerator due to the domestic industry It started late, and few manufacturers and suppliers specialize in system research, development, and application. They generally do not have systematic scientific research, production, application, information feedback, and improvement mechanisms. Therefore, the material quality of foreign products is comparable. Advantage. There is still a considerable distance between the supplier and the design department on the technical connection of the product system performance, which often results in the product not being used to its full potential. For example: EPDM membranes in developed countries are only recommended for municipal wastewater, siliconone synthetic membranes (silicone) are recommended for oily wastewater, urethane membranes (URETHANE) are recommended for chemical wastewater, etc. The EPDM membrane (EPDM) has not yet passed the formulation, but it is commonly used in various sewage treatment projects. Improper operation and maintenance lead to a partial understanding of the product. For example: in a small sewage station, when the aeration system was commissioned, the aerator was operated with high pressure and atmospheric pressure, which caused the diaphragm to burst. Affected by traditional concepts, the aeration type that was put into operation in the same industry in the early years is used to copy, so that some aeration products with superior performance cannot be effectively promoted. Generally speaking, diaphragm type aerators are mainly used in large-scale sewage treatment projects, and tube type aeration is the most popular and has achieved good results. Aerators promoted by the Ministry of Construction No. 218 of the Ministry of Construction's Proclamation of the Application and Restriction of Prohibited Technologies by the Ministry of Construction recommended three types of aerators, namely floating submersible aerators and rotary dish aerators. 3. Medium and microporous aerators. The specific characteristics and application scope of the three types of aerators are as follows: 1) Features of floating submersible aerators: The principle of negative pressure suction is used to place the pump directly in the pool for oxygenation, and the blower room can be cancelled. Installation, maintenance, and management Convenient, non-blocking, low noise, long service life and high comprehensive efficiency. Simplify control procedures and save investment. Power efficiency: 1.7 ～ 2.1 kgO2 / kWh. Scope of application: small and medium-sized urban sewage treatment plants, especially SBR treatment processes with intermittent aeration. 2) Turntable mechanical aerator features: The discs are made of polystyrene foam compression molding or glass fiber reinforced plastic injection molding, with strong stirring ability and a pool depth of up to 4.2m; high inflation efficiency, and the oxygenation capacity of each piece is 0.9 ～ 1.4 kgO2 / h; the liquid velocity at the bottom of the pond is ≥0.3m / s. Scope of application: Circulating oxygenated (oxidized ditch) aeration tanks in urban sewage treatment plants. 3) Meso-micropore aerator Features: Pressurized air passes through the meso-micropore aerator to form tiny air bubbles to aerate the water. Oxygenation efficiency is high, saving energy consumption, low operating costs and long service life. Usually made of corundum, rubber and engineering plastics, quartz and other materials. Corundum material is durable, rubber material has strong anti-blocking ability, engineering plastic material is easy to pickle and regenerate, and quartz material has a long service life. Medium and microporous aerators are available in disc, plate, bell cover, and tube types. The main performances are: theoretical dynamic efficiency ≥4.5kgO2 / kWh; oxygen utilization rate ≥26%. Its physical and chemical and mechanical properties should meet the requirements of CJ / T3015.1 related standards. Among them, the aeration capacity of the tubular aerator is ≥0.60kgO2 / (m / h); the theoretical dynamic efficiency is 7.8kgO2 / kWh. Scope of application: aeration tanks of urban sewage treatment plants, aeration and aeration of natural river channels.