What is the technological process of Jiangnan Sewage Treatment Plant in Nanning, Guangxi? How many steps are needed?

process flow of sewage treatment plant

Sewage enters the plant area through

1. Interception well (allowing sewage that can be treated by the plant to enter the plant area for treatment) to enter

2. Coarse grid (salvaging larger dregs) to

3. Sewage pump (raising the height of sewage) to

4. Fine grid (salvaging smaller dregs) Sedimentation and removal of inorganic particles with high specific gravity in sewage) to

6. Biochemical pond (removing BOD5, SS and various forms of nitrogen or phosphorus in sewage by activated sludge method) to enter

7. Final sedimentation pond (removing excess sludge and reflux sludge) to enter

8. D filter (further reducing SS, Effluent reaches the national first-class standard) and enters ultraviolet rays. 9. Disinfection (killing Escherichia coli in water) and then 1. Effluent < P > Part of the sludge from biochemical pond and final sedimentation pond is used as the return sludge of biochemical pond, and the rest is sent to sludge dewatering room for dehydration and transportation. There are mainly physical treatment, biochemical treatment and chemical treatment. Biochemical treatment is often used. The mainstream treatment method mainly depends on the treated water quality and the receiving water body, and the mainstream treatment method of general urban domestic sewage.

sewage treatment. waste water treatment is some measures or methods adopted to make sewage reach some set standards after being treated by certain methods, discharged into a water body, discharged into a water body or reused, etc.

Modern sewage treatment technology can be divided into primary, secondary and tertiary treatment according to the degree of treatment.

Primary treatment mainly removes sewage. Suspended solid pollutants in water. Most physical treatment methods can only meet the requirements of primary treatment. After primary treatment, BOD can generally be removed by about 3%, which can not meet the discharge standard. Primary treatment belongs to the pretreatment of secondary treatment. < P > Secondary treatment mainly removes colloidal and dissolved organic pollutants (BOD.COD substances) in sewage. The removal rate can reach more than 9%, so that the organic pollutants can meet the discharge standards.

Three-stage treatment, further treatment of refractory organic substances, soluble inorganic substances such as nitrogen and phosphorus, which can lead to eutrophication of water bodies, etc. The main methods include biological nitrogen and phosphorus removal, coagulation and precipitation, sand ratio, activated carbon adsorption, ion exchange and electroosmosis analysis, etc.

The whole process is that the raw sewage deleted through coarse grids is lifted by a sewage lifting pump. After that, it enters the grit chamber. The sewage separated by sand and water enters the primary sedimentation tank. The above is the primary treatment (that is, physical treatment). The effluent from the primary sedimentation tank enters the biological treatment equipment. There are activated sludge process and biofilm process. (The reactors of the activated sludge process include aeration tank, oxidation ditch, etc. The biofilm process includes biological filter, biological turntable, biological contact oxidation process and biological fluidized bed.) The effluent from biological treatment equipment enters the secondary sedimentation tank. The effluent from the secondary sedimentation tank is disinfected and discharged or enters the tertiary treatment. After the primary treatment, it is secondary treatment. The tertiary treatment includes biological nitrogen and phosphorus removal, coagulation sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. Part of the sludge from the secondary sedimentation tank flows back to the primary sedimentation tank or biological treatment equipment. The other part enters the sludge concentration tank. After dehydration and drying, it enters the sludge digestion tank. After preparation, the sludge is finally utilized. Energy consumption analysis of various treatment structures

1. Sewage lifting pump house

The sewage entering the sewage treatment plant enters the sewage lifting pump house through coarse grid deletion, and then is lifted to the forecourt of the grit chamber by the sewage pump. The operation of the pump consumes a lot of energy, which accounts for a considerable proportion of the total energy consumption of the sewage treatment plant. This is related to the sewage flow and the lift to be lifted.

2. The grit chamber

Except for inorganic particles with large specific gravity, the grit chamber is generally located in front of the pumping station and the inverted siphon, so as to reduce the abrasion of inorganic particles to the water pump and pipeline. It can also be installed in front of the primary grit chamber to reduce the load of the grit chamber and improve the treatment conditions of sludge treatment structures. The commonly used grit chambers are advection grit chamber, aeration grit chamber, Dole grit chamber and bell grit chamber.

The main energy supply in the grit chamber is sand water separator and sand suction machine, as well as the aeration system of the aeration grit chamber, the power system of Dole grit chamber and bell grit chamber.

3. Primary grit chamber < The main treatment structure of the plant, or the pre-treatment structure of the secondary sewage treatment plant, is located in front of the biological treatment structure. The treatment objects are SS and part of BOD5, which can improve the operation conditions of the biological treatment structure and reduce its BOD5 load. The primary sedimentation tank includes advection sedimentation tank, radial sedimentation tank and vertical sedimentation tank.

The main energy consumption equipment of the primary sedimentation tank is sludge discharge device, such as chain-belt sludge scraper, sludge scraper and sludge suction pump. Due to the influence of sludge discharge cycle, the energy consumption of the primary sedimentation tank is relatively low.

4. Biological treatment structures < P > The energy consumption of the sewage biological treatment unit process accounts for a considerable proportion of the direct energy consumption of the sewage plant. The sum of the energy consumption of the unit process and the sludge treatment unit process accounts for more than 6% of the direct energy consumption of the sewage plant. The aeration of the aeration system by the activated sludge process consumes a lot of electric energy. It basically runs in conjunction with each other, and its power is relatively high. Otherwise, it will not be good. Results. The treatment effect is not good. The aerator installed in the oxidation ditch treatment process is also energy-intensive equipment. Compared with the activated sludge process, the biofilm treatment equipment has lower energy consumption, but it is less used at present. It is a treatment process that needs to be vigorously promoted in the future.

5. The capacity consumption of the secondary sedimentation tank is mainly in the pumping of sludge and the removal of floating objects indicated by sewage. The energy consumption is relatively low.

6. Sludge treatment < P > The concentration tank, sludge dewatering and drying in the treatment process all consume a lot of electric energy. The energy consumption of sludge treatment unit is quite large. The power consumption of these equipment is very large.