The sewage enters the plant first through
1. interceptor (to let the sewage that the plant can handle enter the plant for treatment) to
2. coarse grating (to salvage the larger scum) to
3. sewage pump (to raise the height of the sewage) to
4. fine grating (to salvage smaller scum) to
5. sand sedimentation tank (based on gravity separation to precipitate and remove the inorganic particles of larger specific gravity) to
.5. sand sedimentation tank (based on gravity separation, the specific gravity of sewage inorganic particles will be precipitated and excluded) to
6. biochemical tank (the use of activated sludge method to remove BOD5, SS and in various forms of nitrogen or phosphorus in the wastewater) into
7. final sedimentation tank (to exclude the residual sludge and reflux sludge) into
8. D-type filtering tank (further reduce SS, so that the effluent water to reach the national standard) into the ultraviolet 9. disinfection (to kill the water of E. coli) and then 10. water
Biochemical tanks, final sedimentation tanks out of the sludge part of the biochemical tanks as a return sludge, the rest of the sludge into the sludge dewatering room dewatering out of the shipment, there are mainly physical treatment, biochemical treatment and chemical treatment, biochemical treatment method is often used, the mainstream treatment method depends on the quality of treated water and the receiving water. The mainstream treatment method mainly depends on the treated water quality and the receiving water body, generally the mainstream treatment method of urban sewage is biochemical treatment method, such as activated sludge method, mbr and other methods.
Sewage treatment. wastewater treatment in order to make sewage after a certain method of treatment. Wastewater treatment. Discharge into a body of water. Wastewater treatment is the process by which wastewater is treated to meet certain standards after it is discharged into a body of water.
Modern wastewater treatment technology. According to the degree of treatment. Can be divided into primary. Secondary and tertiary treatment.
Primary treatment. Mainly removes the solid pollutants in the sewage in a suspended state. Most of the physical treatment method can only complete the requirements of primary treatment. After primary treatment of sewage. BOD can generally remove about 30%. Can not meet the discharge standard. Primary treatment belongs to the pretreatment of secondary treatment.
Secondary treatment. The main removal of colloidal and dissolved organic pollutants in the sewage state (BOD.COD substances). Removal rate of up to 90% or more. Organic pollutants to meet the discharge standards.
Tertiary treatment. Further treatment of difficult to degrade organic matter. Nitrogen and phosphorus and other soluble inorganic substances that can lead to eutrophication of water bodies. The main methods include biological nitrogen and phosphorus removal. Coagulation and precipitation method. Sand rate method. Activated carbon adsorption. Ion exchange method and electroosmosis analysis method.
The whole process of raw sewage through the coarse grid deletion through the sewage lifting pump after lifting. Through the grid deletion or sieve rate. After that, it enters the sand sedimentation tank. After the sand-water separation of sewage into the initial sedimentation tank. Above is the primary treatment (i.e. physical treatment). The effluent from the primary sedimentation tank enters the biological treatment equipment. There are activated sludge method and biofilm method. (The reactor of activated sludge method has aeration tank. Oxidation ditch and so on. Biofilm method includes biofilter. Bio-turntable. Biological contact oxidation and biological fluidized bed). The effluent of the biological treatment equipment enters the secondary sedimentation tank. The effluent from the secondary sedimentation tanks is either disinfected and discharged or goes to tertiary treatment. At the end of the primary treatment, the secondary treatment is completed. Tertiary treatment includes biological nitrogen and phosphorus removal. Coagulation and sedimentation. Sand filtration. Activated carbon adsorption. Ion exchange and electrodialysis. A portion of the sludge from the secondary sedimentation tank is returned to the primary sedimentation tank or biological treatment plant. A part of the sludge goes to the sludge thickener. Afterwards, it enters the sludge digester. After dewatering and drying equipment. The sludge is finally utilized. Analysis of the energy consumption of each treatment structure
1. Sewage lifting pumping station
The sewage entering the sewage treatment plant enters the sewage lifting pumping station through the coarse grating. After that, it is lifted by the sewage pump to the front pool of the sand sedimentation tank. Pump operation consumes a lot of energy. Accounting for a considerable proportion of the total energy consumption of sewage plant operation. This is related to the sewage flow and the head to be lifted.
2. Sedimentation tank
The function of the sedimentation tank is to remove inorganic particles of high specific gravity. Sand sedimentation tank is generally set up in front of the pumping station. Inverted siphon before. In order to reduce inorganic particles on the pump. Pipeline wear, can also be set up in front of the primary sedimentation tank. In order to reduce the load on the sedimentation tank and improve the conditions of sludge treatment structures. Commonly used sand sedimentation tanks are advection sand sedimentation tank. Aerated sand sedimentation tank. Dore sand sedimentation tank and bell-type sand sedimentation tank.
Sedimentation tanks require energy supply is mainly sand and water separator and sand suction machine. As well as the aeration system of the aeration sand sedimentation tank. The power system of the Dore and bell-type sand sedimentation tanks.
3. Primary sedimentation tank
Primary sedimentation tank is the theme of the primary sewage treatment plant treatment structures. Or as a secondary wastewater treatment plant pre-treatment structure
The structure is located in front of the biological treatment structure. The object of treatment is SS and part of the BOD5. It can improve the operating conditions of the biological treatment structure and reduce its BOD5 load. Primary sedimentation tanks include stratified sedimentation tanks. Radial flow sedimentation tank and vertical flow sedimentation tank.
The main energy-consuming equipment of the primary sedimentation tank is the sludge removal device. Such as chain belt scraper. Scraper and skimmer. Suction pump and so on. But due to the influence of the mud removal cycle. Primary sedimentation tank energy consumption is relatively low.
4. Biological treatment structures
The biological treatment of wastewater unit process energy consumption to account for a considerable proportion of the direct energy consumption of sewage plants. It and sludge treatment unit process energy consumption and account for more than 60% of the direct energy consumption of sewage plants. The aeration system of the activated sludge process consumes a large amount of electrical energy. It is basically operated in contact. And the power is large. Otherwise, it will not achieve a good aeration effect. The treatment effect is not good. Oxidation ditch treatment process installed aerator is also a large energy consumption equipment. Biofilm treatment equipment and activated sludge method compared to lower energy consumption. But the current application is less. It is a treatment process that needs to be promoted in the future.
5. Secondary sedimentation tank
The capacity consumption of the secondary sedimentation tank is mainly in the sludge pumping and sewage indicating the removal of floating materials. The energy consumption is relatively low.
6. Sludge treatment
Sludge treatment process in the thickener. Sludge dewatering. Drying consumes a lot of electricity. The energy consumption of the sludge treatment unit is quite large. The power consumption of these equipment is very high.