Underground Buried Sewage Treatment Equipment 50T/D Packaged Stp Plant

50T/D Buried Sewage Treatment Equipment SQDWS-50 Underground

1, Preparation basis for buried sewage treatment equipment scheme
Class III standard in the Environmental Quality Standard for Surface Water (GB 3838-2002);
Emission Standards for Pollutants from Urban Sewage Treatment Plants (GB18918-2002)
Water Quality of Urban Miscellaneous Water for Urban Wastewater Recycling and Reuse (GB/T18920-2002)
Urban Wastewater Recycling and Landscape Environmental Water Quality (GB/T18921-2002)
Code for Design of Building Water Supply and Drainage (GB50015-2003)
Code for Design of Outdoor Drainage (GBJ14-87)
Load Code for the Design of Building Structures GB50009-2001
Code for Design of Concrete Structures GB50010-2002
Code for Seismic Design of Buildings GB50011-2001
Code for Design of Building Foundation GB50007-2002
Code for Fire Protection Design of Buildings GBJ16-87 (revised in 2001)
Code for Electrical Design (GBJ54-83)

2, Legal Background of Buried Sewage Treatment Equipment Scheme
In China, environmental protection is implemented as a basic national policy and highly valued by the entire society and governments at all levels. While implementing the technical standards and specifications mentioned above, the conceptual design of the wastewater treatment plant was prepared in the context of the following legal documents:
Water Pollution Prevention and Control Law of the People's Republic of China (1996)
Environmental Protection Law of the People's Republic of China (December 1989)
Environmental Prevention and Control Law of the People's Republic of China (May 1984)
Measures for the Supervision and Management of Environmental Protection of Pollutant Treatment Facilities (May 1989)
Management Measures for Environmental Protection of Construction Projects (March 1986)
3, Principles for compiling schemes for buried sewage treatment equipment
1. Coordinate and harmonize with the surrounding environment based on the above ground buildings.
2. Adopting mature and reliable domestic treatment processes and technologies to ensure that the treated effluent meets and exceeds the current national standards for miscellaneous water quality; At the same time, minimize engineering investment and operating costs to the greatest extent possible, and reduce the floor area of the entire facility.
3. Adopting high-quality domestic branded equipment and materials that are efficient, energy-saving, technologically advanced, and operate stably and reliably, reducing the maintenance workload of the system and ensuring its long-term normal operation.
4. Fully consider the overall environment, and consider measures such as shock absorption, noise prevention, and deodorization in the design of this wastewater treatment project to minimize the impact on the surrounding environment as much as possible.
5. The facility layout is compact and reasonable, the pipeline installation is neat, and the layout is beautiful.
4, Inlet and outlet water quality
According to the information provided by Party A, the pre treatment raw sewage quality of this project is shown in the table below:

The treated water quality should meet the Class III surface water standards specified in the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), with specific data as shown in the table below:

5, Detailed explanation of buried sewage treatment equipment process
This process plans to adopt the "hydrolysis acidification+contact oxidation+contact oxidation+precipitation+MBR membrane+reverse osmosis" process. This process has simple operation, low operating cost, good treatment effect, and stable operation. It is currently a relatively mature domestic sewage treatment process that can effectively ensure that the sewage meets the discharge standards.
Based on the principles of good treatment effect, low operating cost, and low investment, the specific process flow of this design is as follows:

The sewage first enters the regulating tank for uniform water quality and quantity. The organic content of the sewage in this project is high, with BOD5/CODcr=0.5, and good biodegradability. Therefore, using biological treatment methods to significantly reduce the organic content in the sewage is the most economical. Due to the high content of ammonia nitrogen and organic matter in sewage, especially organic nitrogen, during the biodegradation of organic matter, organic nitrogen will be expressed in the form of ammonia nitrogen, which is also an important pollution control indicator. Therefore, the sewage treatment adopts anoxic and aerobic A/O/O biological contact oxidation process, which requires the biochemical tank to be divided into two parts: A-level tank and O-level tank. The sewage in the regulating tank is lifted to the A-level biochemical tank by a sewage lift pump for biochemical treatment. In the A-level tank, due to the high concentration of organic matter in the sewage, the microorganisms are in a state of hypoxia. At this time, the microorganisms are facultative microorganisms, which convert organic nitrogen in the sewage into ammonia nitrogen. At the same time, they use organic carbon sources as electron donors to convert NO2-- N and NO3-- N into N2, and also use some organic carbon sources and ammonia nitrogen to synthesize new cellular substances. So the A-level tank not only has a certain organic matter removal function, reducing the organic load of the subsequent O-level biochemical tank to facilitate nitrification, but also relies on the high concentration of organic matter in the sewage to complete denitrification and ultimately eliminate nitrogen eutrophication pollution. After the biochemical action of the A-level tank, there is still a certain amount of organic matter and high nitrogen and ammonia present in the sewage. In order to further oxidize and decompose the organic matter, and at the same time, nitrification can proceed smoothly when the carbonization process tends to be complete, an O-level biochemical tank is specially set up.
The effluent from the A-level tank flows into the O-level tank by gravity. The treatment of the O-level biochemical tank relies on autotrophic bacteria (nitrifying bacteria), which use inorganic carbon sources generated by organic matter decomposition or carbon dioxide in the air as a nutrient source to convert ammonia nitrogen in the sewage into NO2-- N and NO3-- N. Part of the effluent from the O-level tank enters the sedimentation tank for sedimentation, while the other part flows back to the A-level tank for internal circulation to achieve denitrification. Fillers are installed in both A-level and O-level biochemical tanks, and the entire biochemical treatment process relies on various microorganisms attached to the filler to complete. Control the dissolved oxygen in the A-level tank at around 0.5mg/l; The dissolved oxygen in the O-level biochemical tank should be controlled above 3mg/l, and the gas-water ratio should be 15:1. A portion of the effluent from the O-level biochemical tank flows back into the A-level tank,; A portion flows into a vertical flow sedimentation tank for solid-liquid separation. After being treated in a hydrolysis acidification tank, the wastewater enters a contact oxidation/membrane bioreactor MBR. Under the action of aerobic bacteria, most of the remaining BOD5 in the wastewater can be degraded into CO2 and H2O. In addition, membrane interception can better remove suspended solids and pathogenic microorganisms in water. The wastewater after MBR treatment flows into the clean water tank and meets the discharge standards.
The effluent after solid-liquid separation in the sedimentation tank flows into the clear water tank and then enters the reverse osmosis equipment for deep treatment before being discharged.
The sludge settled in the sedimentation tank is partially lifted to the A-level tank by the air stripping device for internal circulation; Part of it is lifted to the sludge tank; The sludge in the sludge tank is regularly transported by manure trucks for treatment.

6, Process characteristics of buried sewage treatment equipment
The treatment process of hydrolysis acidification+biological contact oxidation+biological contact oxidation+sedimentation+MBR membrane+reverse osmosis biological treatment adopted in this design has been widely applied in domestic sewage treatment, with the following main characteristics:
1. The hydrolysis acidification process replaces the single function primary sedimentation tank, which has the following advantages compared to the primary sedimentation tank: high removal rate of suspended solids, increased biodegradability of wastewater, and can reduce the load of subsequent aerobic treatment; It has a stable digestion effect on sludge, reducing the system's sludge production.
2. The aerobic biochemical part adopts a biological contact oxidation process, which has high volumetric load and small footprint. It has the advantages of both activated sludge method and biofilm method, and has good treatment effect, strong impact resistance, simple and convenient management, and low energy consumption.
3. The ammonia nitrogen content of this sewage is high, and denitrification treatment of the sewage needs to be considered. The hydrolysis acidification+biological contact oxidation process used in this process is the anoxic+aerobic denitrification and denitrification process. During the operation, the aerobic nitrification solution flows back to the hydrolysis tank, and under the catalysis of denitrifying bacteria, nitrate nitrogen and nitrite nitrogen are converted into nitrogen and separated from the sewage.
4. Adopting new fillers, fast film formation, long service life, and fast treatment effect;
5. Fully consider the possibility of secondary pollution and minimize its impact;
6. Adopting centralized control and automated operation, it is easy to manage and maintain, improving system reliability and stability.