A sewage treatment system and operation method in an alpine region

Abstract

The application relates to the field of energy-saving and environment-friendly technologies, and particularly discloses a sewage treatment system and operation method for high-cold regions; the sewage treatment system comprises a pretreatment unit, a biological treatment unit and a terminal treatment unit which are sequentially connected and arranged in a heat preservation area; the pretreatment unit comprises three-stage grid pools and three-stage grit chambers and is used for intercepting solid impurities and inorganic particles in sewage in stages; the biological treatment unit is composed of three-stage anaerobic pools, three-stage anoxic pools and three-stage aerobic pools, and organic matter degradation is realized through segmented treatment of the three-stage anaerobic pools, the three-stage anoxic pools and the three-stage aerobic pools; the terminal treatment unit comprises three-stage sedimentation pools, three-stage filtration pools and a disinfection pool and is used for solid-liquid separation and filtration disinfection; a heat preservation structure is further arranged on the top of the heat preservation area, and the heat preservation structure at least comprises a soil covering layer and a heat preservation layer; the heat preservation structure does not need external heat sources, can reduce energy consumption and saves operation cost.

Description

Technical Field

[0001] This invention relates to the field of energy conservation and environmental protection technology, and in particular to a wastewater treatment system and operation method for high-altitude and cold regions. Background Technology

[0002] In the high-altitude, cold regions of my country's upper reaches of the Yangtze and Yellow Rivers, important ecological barriers are typically formed. These areas have relatively fragile ecosystems and require exceptionally high levels of ecological protection. Their climate is characterized by extreme diurnal temperature variations, extremely low winter temperatures, and often deep permafrost. The persistently low temperatures result in relatively low wastewater temperatures, directly impacting the effectiveness of biological treatment processes and making wastewater treatment exceptionally difficult. In these high-altitude, cold regions, low temperatures are a constant state; for example, in Litang County, Sichuan Province, winter temperatures frequently remain around -20°C. On February 17, 2024, the region even experienced a record low temperature, plummeting to -37°C. However, for biological wastewater treatment units, the average temperature should be controlled between 10 and 20°C to ensure the normal activity of water treatment microorganisms. When the water temperature drops below 5°C, the reactivity of these microorganisms is severely inhibited, with their biological activation efficiency decreasing by more than 70% compared to suitable temperatures. This directly leads to wastewater treatment indicators failing to meet expected standards. In practical applications, although integrated wastewater treatment equipment is installed directly on the construction site, this equipment is generally suitable for smaller wastewater treatment plants. Even so, the treatment effect is still unsatisfactory due to the persistent problem of low water temperature.

[0003] The patent "An Energy-Saving Wastewater Treatment Device for High-Altitude Cold Regions" (authorization announcement number CN117401824B, hereinafter referred to as Prior Art 1) discloses a wastewater treatment device for high-altitude cold regions. In the current technical field, a wind-driven fan, combined with vertical and horizontal air distribution pipes, has achieved a reoxygenation process in the wastewater tank. This technology allows the degradation tank to alternate between aerobic and anaerobic operations, effectively removing harmful pollutants such as chemical oxygen demand (COD) and ammonia nitrogen from the wastewater. Furthermore, by carefully designing the transmission ratio of the two transmission components, the rotation speed of the stirring device in the anaerobic tank can be ensured to be lower than that in the facultative anaerobic tank. This design not only improves the efficiency of wastewater treatment but also enhances the reliability of the entire treatment process.

[0004] However, it's important to note that this type of wastewater treatment equipment is typically suitable for smaller wastewater treatment plants. They may encounter problems with treatment efficiency, especially at lower water temperatures. This is primarily because low temperatures slow down the metabolic activity of microorganisms, thus affecting the efficiency and quality of wastewater treatment. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a wastewater treatment system and operation method for high-altitude and cold regions, in order to solve the problem that the activity of microorganisms in the wastewater treatment system will be significantly reduced in high-altitude and cold regions or when the winter temperature is extremely low, especially when the temperature is below 5°C, the reactivity of microorganisms will be greatly inhibited, resulting in a significant decrease in wastewater treatment efficiency.

[0006] In a first aspect, embodiments of the present invention provide a wastewater treatment device for high-altitude and cold regions, comprising a pretreatment unit, a biological treatment unit, and a terminal treatment unit sequentially connected and arranged within an insulated zone; the pretreatment unit includes three sections of grit chambers and three sections of sedimentation tanks for progressively intercepting solid impurities and inorganic particles in wastewater; the biological treatment unit consists of three sections of anaerobic tanks, three sections of anoxic tanks, and three sections of aerobic tanks, and achieves organic matter degradation through segmented treatment in the three sections of anaerobic tanks, three sections of anoxic tanks, and three sections of aerobic tanks; the terminal treatment unit includes three sections of sedimentation tanks, three sections of filtration tanks, and a disinfection tank for solid-liquid separation and filtration disinfection; the top of the insulated zone is also provided with an insulation structure, which includes at least a soil cover layer and an insulation layer.

[0007] Preferably, the spacing between the three sections of the grit chamber decreases progressively, with the spacing of the first section being 30-50 mm, the second section being 10-20 mm, and the third section being 5-10 mm. The three grit chambers are respectively a combination of horizontal flow grit chamber, aerated grit chamber, and vortex grit chamber, and the separation of sand particles is achieved through hydraulic control.

[0008] Preferably, a sludge return channel is provided between the three anaerobic tanks and the three anoxic tanks, and a mixed liquor return system is provided at the bottom of the three aerobic tanks to return the nitrified liquor to the anoxic tanks; the aeration intensity of the three aerobic tanks decreases progressively, with the aeration rate of the first aerobic tank being 3-5 m³ / h. 3 The aeration rate in the second aerobic tank is 2–3 m³ / h, and the aeration rate in the third aerobic tank is 1–2 m³ / h. 3 / h.

[0009] Preferably, the disinfection tank is equipped with an ultraviolet disinfection device and an online water quality monitoring system to monitor COD, ammonia nitrogen, total phosphorus and fecal coliform indicators in real time, so that they meet the standards before discharge; The three-stage filtration unit consists of a sand filter, a fiber ball filter, and an activated carbon filter, with the filtration accuracy increasing by 0.5 to 1 micrometer at each stage.

[0010] Preferably, the three sections of the grit chamber, the three sections of the sedimentation chamber, the three sections of the anaerobic chamber, the three sections of the anoxic chamber, the three sections of the aerobic chamber, the three sections of the sedimentation chamber, the three sections of the filtration chamber, and the disinfection chamber are arranged in sequence with their heights gradually decreasing, and an equipment layout area is set up in the space enclosed by the U-shaped ring.

[0011] Preferably, the insulation layer is composed of 20-30mm sprayed rigid polyurethane foam and 35-45mm lightweight aggregate insulating concrete, and the soil covering thickness is at least greater than 2.0m; wherein, a composite insulation block layer is also provided on the outer side of the insulation area, the layer thickness of the composite insulation block is greater than or equal to 240mm, and a 20-30mm rigid polyurethane foam board is filled in the middle.

[0012] Preferably, it also includes several wastewater pipes; the wastewater pipes in the equipment layout area adopt a gravity flow design and have a slope greater than or equal to 0.5%; the power equipment in the equipment layout area is centrally arranged.

[0013] Secondly, a wastewater treatment method for high-altitude and cold regions is provided, comprising: calculating the thickness of the insulation layer and the thickness of the cover layer based on the local air temperature, wastewater temperature and operating requirements; sequentially arranging a pretreatment unit, a biological treatment unit and a terminal treatment unit within the insulation zone, and insulating the pretreatment unit, biological treatment unit and terminal treatment unit through the insulation layer and the cover layer; gradually flowing the wastewater through the pretreatment unit, biological treatment unit and terminal treatment unit for treatment, and discharging it after it meets the standards.

[0014] Preferably, the thermal conductivity of the insulation structure is less than 0.05 W / (m²·K), and the soil cover thickness is greater than or equal to the maximum frost thickness.

[0015] Preferably, the wastewater is characterized by being treated stepwise through a pretreatment unit, a biological treatment unit, and a terminal treatment unit before being discharged after meeting the standards. This includes: the wastewater entering from the wastewater pipe on the left side, passing through three sections of grit chambers and three sections of sedimentation tanks for preliminary pretreatment; then flowing into three sections of anaerobic tanks, three sections of anoxic tanks, and three sections of aerobic tanks for biological treatment; then passing through three sections of sedimentation unit and three sections of filtration unit for terminal treatment; and finally entering a disinfection tank for disinfection before being discharged after meeting the standards.

[0016] The wastewater treatment system and operation method for high-altitude and cold regions provided by this invention have the following beneficial effects: The insulation structure described in this invention, by installing a soil covering layer and an insulation layer above the wastewater treatment tank and equipment, effectively reduces heat loss during wastewater treatment, ensuring the system maintains a stable treatment temperature even in extremely cold climates. The selection of insulation material and the design of its thickness ensure that the wastewater treatment system maintains a suitable temperature in low-temperature environments, preventing a significant decrease in microbial activity in the biological treatment unit due to low temperatures, thereby improving wastewater treatment efficiency. Especially in high-altitude and cold regions, this insulation structure eliminates the need for an external heat source, reducing energy consumption and operating costs. It also prevents damage or performance degradation to wastewater pipes and treatment structures due to freezing, thus extending the system's service life and reducing maintenance costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of the present invention.

[0018] Figure 1 This is a schematic diagram of a wastewater treatment system for high-altitude and cold regions. Figure 2 This is a plan view of a wastewater treatment system for high-altitude and cold regions. Figure 3 This is a schematic cross-sectional view of a wastewater treatment system in a high-altitude, cold region. Parts and component numbers in the diagram: 1-Wastewater pipe, 2-Grit chamber, 3-Sedimentation tank, 4-Anaerobic tank, 5-Anoxic tank, 6-Aerobic tank, 7-Sedimentation tank, 8-Filter tank, 9-Disinfection tank, 10-Manhole, 11-Equipment layout area, 12-Wastewater treatment equipment, 13-Insulation layer, 14-Side insulation structure layer, 15-Covering layer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, the element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Where there is no conflict, embodiments of the present invention and the various features thereof can be combined with each other, all of which are within the scope of protection of the present invention.

[0020] Example 1

[0021] Please see Figure 1 and Figure 2 This invention provides a wastewater treatment device for high-altitude and cold regions, ensuring that the wastewater treatment system can operate stably and efficiently in low-temperature environments without the need for external heat intervention.

[0022] In this invention, the proposed wastewater treatment equipment 12 is a comprehensive system comprising a series of treatment units connected sequentially and arranged within an insulated area. These treatment units sequentially include a pretreatment unit, a biological treatment unit, and a final treatment unit. First, the pretreatment unit removes larger, heavier solids and impurities from the wastewater. Through this stage of treatment, the wastewater is initially purified, providing a cleaner water source for the subsequent biological treatment unit. This design effectively prevents potential blockages or damage in subsequent equipment and processes, ensuring the smooth operation of the entire system. Next, the biological treatment unit utilizes the natural action of microorganisms to effectively degrade and transform organic matter in the wastewater. During this process, harmful pollutants such as ammonia and phosphorus are removed, significantly reducing the pollution load and achieving water purification. Finally, the final treatment unit performs further solid-liquid separation, filtration, and disinfection of the biologically treated wastewater. Through this series of treatments, it is ensured that the final discharged water quality fully meets environmental standards, effectively preventing potential environmental harm from pollutants.

[0023] The coordinated operation of these three treatment units ensures the complete wastewater treatment process, from initial physical removal to biodegradation and final purification. This system design not only guarantees high efficiency but also ensures that the treated water meets standard discharge requirements. Furthermore, these treatment devices are cleverly housed within insulated areas, a design that effectively maintains the wastewater temperature during treatment, which is crucial for microbial activity and overall treatment efficiency.

[0024] Please see Figure 1 The pretreatment unit includes a three-section grit chamber 2 and a three-section grit chamber 3, used to intercept solid impurities and inorganic particles in the sewage step by step; the biological treatment unit consists of a three-section anaerobic tank 4, a three-section anoxic tank 5 and a three-section aerobic tank 6, and achieves organic matter degradation through the three-section anaerobic tank 4, three-section anoxic tank 5 and three-section aerobic tank 6; the end treatment unit includes a three-section sedimentation tank 7, a three-section filtration tank 8 and a disinfection tank 9, used for solid-liquid separation and filtration disinfection.

[0025] The three sections of the screen tank 2, the three sections of the grit chamber 3, the three sections of the anaerobic tank 4, the three sections of the anoxic tank 5, the three sections of the aerobic tank 6, the three sections of the sedimentation tank 7, the three sections of the filtration tank 8, and the disinfection tank 9 are arranged in a loop-like arrangement, leaving some space in the middle after installation. Compared to other treatment tank arrangements (such as longitudinally arranged tanks), these loop-like arrangement requires less vertical ground depth, mainly requiring horizontal construction, making construction easier and facilitating the installation of this type of treatment tank.

[0026] Please see Figure 1 The screen 2 typically consists of coarse and fine screens, which are a set of parallel metal or plastic bar screens installed at the front end of the wastewater treatment facility. Different spacing can be used to intercept solid debris of different sizes. Mechanical or manual cleaning devices are generally provided to periodically remove the intercepted debris. The screen size decreases progressively in the three sections. The screens can be periodically lifted and cleaned mechanically, and then reset after cleaning.

[0027] The principle of the screen tank 2 is mainly physical interception. After sewage enters the screen tank 2, the water flows through the gaps between the screen bars, while larger floating objects, such as branches, plastic bags, rags, and large particles of solid waste, are blocked by the screen bars. If these solid debris are not removed, they may damage downstream treatment equipment, such as water pumps and pipelines, affecting the normal operation of the entire treatment system. The coarse screen can intercept larger solid objects, while the fine screen further intercepts smaller suspended solids to ensure the smooth operation of subsequent treatment units.

[0028] Please see Figure 1 The grit chamber 3 comes in various types, commonly including horizontal flow grit chambers 3, aerated grit chambers 3, and vortex grit chambers 3. They generally have a certain length, width, and depth, and include an inlet, an outlet, and a sedimentation hopper. A horizontal flow grit chamber 3 is a rectangular tank where water flows horizontally; an aerated grit chamber 3 has an aeration device at the bottom, creating a swirling flow; a vortex grit chamber 3 utilizes the principle of hydraulic vortex flow, forming a vortex through a special design of the inlet and outlet. The three grit chambers 3 can be combined in the same or different types depending on the specific water quality conditions for grit treatment. Generally, a combination of horizontal flow grit chambers, aerated grit chambers, and horizontal flow grit chambers, or a combination of horizontal flow grit chambers, vortex grit chambers, and horizontal flow grit chambers, is used.

[0029] The grit chamber 3 utilizes the principle of physical sedimentation, allowing heavier inorganic particles such as sand in the wastewater to settle to the bottom under the influence of gravity or centrifugal force. In a horizontal flow grit chamber, because the water flow velocity is maintained within a certain range during design, heavier sand particles settle quickly under gravity, while lighter substances such as organic matter flow out with the water. The aerated grit chamber 3 uses the rising airflow generated by aeration to separate sand particles from organic matter. Because the sand particles are heavier, they sink to the bottom, while the organic matter is suspended in the water and flows out under the combined action of water and airflow. The vortex grit chamber uses hydraulic vortexing to cause sand particles to sink to the sand hopper at the bottom center under centrifugal force, achieving separation of sand particles and organic matter. Removing sand particles from wastewater can prevent wear and blockage of subsequent treatment equipment and pipelines.

[0030] The anaerobic tank 4 is a sealed or semi-sealed tank that provides an anaerobic environment for microorganisms. A stirring device can be installed inside the tank to ensure thorough mixing of wastewater and microorganisms. Different zones can be set up as needed to promote anaerobic reactions at different stages. The three-stage anaerobic tank 4 has a consistent structural design, and a fully enclosed tank is recommended.

[0031] Anaerobic tank 4 is where anaerobic microorganisms decompose complex organic matter in wastewater into simpler organic matter and some intermediate products under anaerobic conditions. It mainly includes three stages: hydrolysis, fermentation, and methanogenesis. The hydrolysis stage breaks down large organic molecules (such as proteins and polysaccharides) into smaller organic molecules (such as amino acids and monosaccharides); the fermentation stage converts these smaller organic molecules into fatty acids and alcohols; and the methanogenesis stage further converts these products into gases such as methane and carbon dioxide. Anaerobic treatment can reduce the organic matter content of wastewater and simultaneously produce biogas, achieving energy recovery. The recovered biogas can be used for cooking in the canteen and heating in the staff quarters, depending on usage needs.

[0032] The anoxic tank 5 is generally a tank structure and requires a stirring device to ensure uniform mixing of wastewater and microorganisms. An internal recirculation system can be installed to return the mixed liquid from the aerobic tank 6 to the anoxic tank 5. The three anoxic tanks 5 have the same structural type and are generally fully enclosed tanks.

[0033] The anoxic tank 5 primarily utilizes denitrifying bacteria to reduce nitrates and nitrites in the returned nitrifying liquid into nitrogen gas under anoxic conditions (no molecular oxygen but the presence of combined oxygen such as nitrates and nitrites), thereby achieving denitrification. The anoxic tank 5 receives a mixed liquid containing nitrates and nitrites from the aerobic tank 6, and simultaneously utilizes the organic carbon source in the wastewater as an electron donor. Under the action of denitrifying bacteria, a denitrification reaction occurs, achieving the removal of nitrogen from the wastewater.

[0034] The aerobic tank 6 typically takes various forms, such as an aeration tank in the activated sludge process or a biological contact oxidation tank. The aeration tank is equipped with aeration devices, such as microporous aerators or jet aerators, to provide sufficient oxygen for the microorganisms. The biological contact oxidation tank contains packing material on which microorganisms attach and grow. The aerobic tank 6 generally has a sludge return system, returning a portion of the activated sludge settled in the third aerobic tank 6 to the first aerobic tank 6. The three aerobic tanks 6 have identical structures, with the aeration rate and intensity gradually decreasing across the three stages.

[0035] The aerobic tank 6 utilizes aerobic microorganisms to oxidize and decompose organic matter in wastewater under aerobic conditions, converting it into carbon dioxide and water. For the activated sludge process, the aeration device provides oxygen, allowing aerobic microorganisms (such as bacteria, protozoa, and metazoa) to metabolize and reproduce organic matter in an aerobic environment. Simultaneously, nitrifying bacteria convert ammonia nitrogen into nitrates and nitrites, preparing for subsequent denitrification. For the biological contact oxidation process, microorganisms attach to the packing material to form a biofilm, treating organic matter and ammonia nitrogen in the wastewater under sufficient oxygen conditions.

[0036] The sedimentation unit comprises a square tank with an inlet zone, a sedimentation zone, a sludge hopper, and an effluent zone. The sedimentation zone is the core component, where suspended solids settle by gravity. Inclined tube or inclined plate sedimentation devices can be used to improve sedimentation efficiency. The sedimentation units generally have a consistent form, and each stage can be equipped with an bypass pipe. Part of the settled sludge can be returned to the anaerobic tank to maintain biological activity, while the other part can be pumped to a filter press for filtration.

[0037] The sedimentation unit utilizes the principle of gravity sedimentation to allow suspended solids in the wastewater to settle in the sedimentation tank 7. After biological treatment, the wastewater enters the sedimentation unit. Due to the slowed water flow, microbial flocs (such as activated sludge or biofilm fragments) settle to the sludge hopper at the bottom of the tank under gravity, forming sludge and achieving solid-liquid separation, which greatly reduces the suspended solids content of the wastewater.

[0038] The filtration unit typically takes the form of a sand filter, a fiber ball filter, or an activated carbon filter. A sand filter consists of layers of sand with varying particle sizes; a fiber ball filter is filled with fiber balls; and an activated carbon filter is filled with activated carbon granules or fibers. It has an inlet, a filter media layer, a support layer, and an outlet; some also include a backwashing device to ensure long-term stable operation. A typical three-stage filtration system will consist of a sand filter + a fiber ball filter + an activated carbon filter, with the overall filtration precision progressively increasing.

[0039] The aforementioned filtration units utilize physical filtration principles. As wastewater passes through the filter media layer, fine suspended solids, colloids, and other impurities are trapped, further removing residual solid particles and some organic matter, thus improving the clarity and quality of the wastewater. Sand filters rely on the filtration effect of sand particles; fiber ball filters utilize the adsorption and interception of fiber balls; and activated carbon filters, in addition to physical filtration, also utilize the adsorption effect of activated carbon to adsorb some dissolved organic matter and odor substances, further improving water quality.

[0040] The disinfection tank 9 can be a rectangular tank equipped with a dosing device or disinfection equipment. Common disinfection methods include ultraviolet disinfection, chlorine dioxide disinfection, and liquid chlorine disinfection. For chemical disinfection, dosing points and stirring devices are provided to ensure uniform mixing of the disinfectant; for ultraviolet disinfection, ultraviolet lamps are installed. Considering both cost and convenience, the ultraviolet disinfection tank 9 is often chosen.

[0041] The ultraviolet disinfection utilizes the bactericidal effect of ultraviolet light to destroy the DNA structure of microorganisms, rendering them inactive. Chlorine dioxide and liquid chlorine disinfection, on the other hand, use the strong oxidizing properties of disinfectants to oxidize the cell structure and enzyme system of microorganisms, killing them and achieving the purpose of disinfection. This ensures that the effluent meets discharge standards and prevents pathogenic microorganisms in sewage from harming the environment and human health.

[0042] In this embodiment of the invention, a three-section grit chamber 2, a three-section grit chamber 3, a three-section anaerobic chamber 4, a three-section anoxic chamber 5, a three-section aerobic chamber 6, a three-section sedimentation chamber 7, a three-section filtration chamber 8, and a disinfection chamber 9 are arranged in a loop-shaped, encircling layout to form a connected, integrated treatment structure. This layout effectively concentrates heat within the chambers, preventing heat loss. Especially in cold environments, this layout helps maintain minimal temperature differences between units, ensuring the entire system maintains a stable operating temperature at low temperatures. Furthermore, the loop-shaped, encircling design makes the wastewater flow path more concentrated and closed during treatment, and the direction of water flow helps heat circulate and distribute within the system. Particularly in the biological treatment unit, heat exchange between chambers and internal water circulation contribute to improved temperature stability. Thus, heat does not rapidly dissipate between treatment chambers, helping to maintain the higher temperatures required for microbial growth and ensuring efficient biological treatment.

[0043] The circular layout, due to the compact arrangement of the tanks, allows the external insulation layer 13 and the cover layer 15 to form a common insulation barrier, reducing the impact of external cold air on the system. The circular layout brings the treatment tanks closer together, enabling them to share the benefits of the cover layer 15 and the insulation layer 13, thereby reducing temperature fluctuations caused by cold external climates. This structure improves the system's adaptability to low temperatures, ensuring that even in extremely cold weather, the wastewater temperature within the system remains within a suitable range.

[0044] The circular, ring-shaped design also minimizes the temperature difference between the tanks, avoiding the problem of excessive temperature variations that can occur in traditional layouts (e.g., tanks farther from the heat source may be colder; wastewater flow can lead to heat loss). The ring-shaped layout ensures that each treatment tank is in a relatively uniform thermal environment, helping to maintain the stability of the treatment process, especially in cold regions, preventing some tanks from becoming too cold and affecting microbial activity or treatment efficiency.

[0045] The circular, ring-shaped layout of the tanks reduces heat loss and minimizes the need for additional heating. Due to the close arrangement of the tanks and shared insulation, the demand for external heat sources is significantly reduced, saving energy. This design not only saves energy in cold regions but also avoids the additional investment and maintenance costs of external heating equipment, lowering the overall operating costs of the wastewater treatment system. In summary, the circular, ring-shaped layout helps improve the system's thermal efficiency, reduces interference from cold air, and ensures stable operation of wastewater treatment systems in cold regions during winter, offering excellent insulation and economic benefits.

[0046] The rational layout of equipment area 11 facilitates centralized management and maintenance of power equipment, backwashing systems, and dosing systems, improving operational efficiency. Wastewater pipeline 1 is designed to enter the wastewater treatment tank and equipment by gravity flow, reducing reliance on additional power equipment, lowering operating costs, and also reducing the risk of pipeline rupture due to excessive pressure. This is especially important in low-temperature environments in cold regions. The three-stage unit treatment and the loop-shaped layout place the main biological treatment in the center of equipment area 11, effectively reducing heat loss. The unit can effectively improve the removal rate of pollutants, increase wastewater treatment efficiency, and ensure the central temperature of the biological treatment unit. This ensures that the temperature of aerobic tank 6 is 2-3°C higher than that of anaerobic tank 4 and anoxic tank 5 during operation. The treatment process proceeds from the outside in, with the treatment temperature gradually increasing. The soil cover layer 15 provides good insulation, and the natural heat dissipation of the central equipment also helps to increase the temperature of the downstream water treatment tanks.

[0047] Furthermore, after these treatment tanks are arranged in a U-shape, an equipment layout area 11 and a related auxiliary facilities layout area are set up within the space they form. During operation, wastewater flows sequentially through each treatment unit via wastewater pipe 1 to complete the entire wastewater treatment process and is discharged after meeting standards. When personnel need to enter the system for operation, maintenance, and repair, manholes 10 facilitate the work. The equipment layout area 11 also centrally houses power equipment, backwashing systems, and chemical dosing systems, facilitating management and operation control.

[0048] Preferably, the spacing between the three sections of the grid pool 2 decreases progressively, and the spacing of the first section of the grid pool 2 is 30-50mm, which mainly intercepts larger floating objects, such as tree branches, plastic bags, and large particles of garbage.

[0049] The second section of the screen tank 2 has a spacing of 10-20mm, which further removes smaller suspended solids and ensures that particulate matter in the sewage is screened out more finely, providing a cleaner water source for the subsequent grit chamber 3 and biological treatment unit.

[0050] The third section of the screen tank 2 has a spacing of 5-10mm, which thoroughly filters out finer debris, ensuring that there are almost no particulate matter in the sewage to avoid clogging and wear on subsequent equipment (such as pumps, pipes, reaction tanks, etc.).

[0051] The three-stage grit chamber 3 adopts a combination of horizontal flow grit chamber 3, aerated grit chamber 3, and vortex flow grit chamber 3, respectively, and achieves grit separation through hydraulic control. The combination of the three-stage screen 2 and different types of grit chambers 3 can adapt to the wastewater treatment needs of various water qualities, especially for wastewater with high particulate matter content or large particle size differences, demonstrating good adaptability and treatment effect. The different types of grit chambers 3 work together to ensure effective separation of particles of various sizes, thereby improving the overall operating efficiency of the system.

[0052] This three-stage setup ensures that particulate matter and impurities are fully removed after wastewater pretreatment, reducing the burden on subsequent biological treatment and end-of-pipe treatment units.

[0053] For example, biological treatment units (such as anaerobic tank 4, anoxic tank 5, and aerobic tank 6) can operate in cleaner water sources, reducing the load on microorganisms and helping to improve their treatment efficiency.

[0054] End-of-pipe treatment units (such as sedimentation tank 7 and filtration tank 8) can also remove suspended solids in the water more efficiently, ensuring that the effluent quality meets discharge standards.

[0055] Furthermore, this combination of progressively decreasing grit chamber 2 and three different types of grit chambers 3 effectively improves the solids removal efficiency in the wastewater pretreatment stage, reduces the burden on subsequent treatment units, and enhances the system's treatment efficiency, stability, and equipment lifespan, while also reducing maintenance costs. This setup can handle wastewater with high concentrations of solids while ensuring efficient and stable treatment results.

[0056] A sludge return channel is provided between the three anaerobic tanks 4 and the three anoxic tanks 5, and a mixed liquor return system is installed at the bottom of the three aerobic tanks 6 to return the nitrified liquor to the anoxic tanks 5. Specifically, the sludge return channel allows the treated sludge to be returned to the front end of the anaerobic tank 4, maintaining the microbial concentration in the anaerobic tank 4 and improving its treatment capacity and efficiency. In the anoxic tank 5, the nitrates in the returned sludge provide a continuous ammonia source for the denitrification reaction, promoting the growth of denitrifying bacteria and nitrogen removal, thus improving the ammonia removal effect. The return of the nitrified liquor provides nitrates to the anoxic tank 5, ensuring the smooth progress of the denitrification reaction. The nitrates in the returned nitrified liquor provide a sufficient ammonia source for the denitrifying bacteria, ensuring the efficient progress of the ammonia removal process. Enhanced reaction stability: The return of the mixed liquor maintains the stability of the removal process of pollutants such as phosphorus within the system, while avoiding the impact of water quality fluctuations on biological treatment efficiency.

[0057] The aeration intensity of the three aerobic tanks 6 decreases progressively, with the aeration rate of the first aerobic tank being 3-5 m³ / s. 3 The aeration rate in the second aerobic tank is 2–3 m³ / h, and the aeration rate in the third aerobic tank is 1–2 m³ / h. 3 / h.

[0058] In the staged oxidation process, the high aeration rate in the first aerobic tank ensures that organic matter in the water is fully degraded by aerobic microorganisms, providing treated water for subsequent tank stages. As water quality gradually improves, the aeration rate in subsequent tank stages gradually decreases, avoiding excessive oxygen supply and reducing unnecessary energy consumption. It also controls biofilm growth, ensuring optimal growth environments for microorganisms at different stages. In practical applications, the lower aeration rate in the third aerobic tank (stage 6) helps avoid oxygen excess, reducing stress on microorganisms while enhancing the activity of denitrifying bacteria. This facilitates further wastewater treatment, especially in wastewater with high ammonia and high COD levels, thus reducing system operating costs.

[0059] To ensure that the discharged water meets hygiene standards, an ultraviolet (UV) disinfection device and an online water quality monitoring system are installed in disinfection tank 9. These systems monitor COD, ammonia nitrogen, total phosphorus, and fecal coliform levels in real time, ensuring that the water meets standards before discharge. UV disinfection is a highly efficient method that effectively kills pathogenic microorganisms (such as bacteria and viruses) in the water. UV disinfection involves no chemical additives, does not produce secondary pollution, and avoids harm to the environment and human health.

[0060] Real-time monitoring of water quality indicators such as COD (Chemical Oxygen Demand), ammonia nitrogen, total phosphorus, and fecal coliforms ensures that water quality consistently meets discharge standards. If water quality fails to meet standards, the system can remedy the situation by adjusting processes or adding disinfectants. The introduction of this monitoring system improves its adaptability and response speed, making the entire wastewater treatment process more precise and reliable. The online monitoring system automatically records and reports water quality data, reducing manual operation, ensuring real-time control and data analysis, and improving the accuracy and efficiency of water quality monitoring.

[0061] The filtration precision is progressively increased (to 0.5–1 micrometer) within each of the filtration units (sand filter, fiber ball filter, and activated carbon filter). The sand filter, as the primary filtration unit, effectively removes larger suspended solids from the water, reducing the burden on subsequent filters and ensuring thorough removal of coarser solid impurities. The fiber ball filter offers even higher filtration precision, removing smaller suspended solids and colloidal substances to further purify the water and achieve higher water quality standards. Activated carbon possesses excellent adsorption properties, removing dissolved organic matter, odor substances, and some dissolved ammonia and phosphorus pollutants, ensuring better purification results. Furthermore, the activated carbon filter can adsorb trace amounts of harmful substances in the water, effectively removing residual pollutants.

[0062] Through a multi-stage filtration design (sand filter - fiber balls - activated carbon), it can ensure that everything from larger particles to extremely fine colloidal substances can be removed efficiently, gradually improving the water purification effect and ultimately ensuring that discharge standards are met.

[0063] A soil cover layer 15 is installed above the wastewater treatment tank and equipment, and a top structural insulation layer 13 is installed between the two. The insulation layer 13 can be made of one or a combination of materials such as extruded polystyrene foam (extruded board), molded polystyrene foam (ordinary foam board), sprayed rigid polyurethane foam, rigid polyurethane foam insulation board (product), foamed concrete (foamed mortar), chemically foamed cement board, lightweight aggregate insulation concrete (ceramsite concrete, etc.), inorganic insulation mortar (vitrified microsphere insulation mortar), polystyrene particle insulation mortar, mineral wool (rock wool), phenolic resin board, expanded perlite insulation mortar, and inorganic active wall insulation materials. The thickness of the insulation layer 13 is calculated based on comprehensive factors such as local air temperature and wastewater temperature operation requirements. The thermal conductivity of the insulation structure is less than 0.05 W / (m²·K), and the thickness of the soil cover layer 15 is greater than or equal to the maximum frost thickness.

[0064] This design effectively utilizes the soil's heat-insulating properties, reducing heat loss during wastewater treatment and maintaining a relatively stable temperature environment in winter. This promotes microbial growth and metabolism, ensuring effective wastewater treatment. Simultaneously, the soil cover layer 15 protects treatment structures and equipment from frost heave damage, extending the system's lifespan.

[0065] Please see Figure 3 For example, in Litang County, the maximum frost depth is approximately 86-120cm. To ensure that the soil temperature below the frost layer is not lower than 10℃, winter soil temperature monitoring can be conducted at the project site. Based on local experience, the soil temperature at 2.0m below the frost layer can be controlled at around 4℃. To save investment, the top of the structure is filled with 20-30mm of sprayed rigid polyurethane foam or rigid polyurethane foam insulation board, covered with 35-45mm of lightweight aggregate insulating concrete (such as ceramsite concrete), and then covered with a 152.0m layer of soil. A side insulation structure layer 14 is set around the perimeter of the structure and equipment layout area 11, using an insulation design. The insulation layer 13 adopts a composite structure. Under the condition that the structural strength requirements of the structure are met, lightweight aggregate insulating concrete (such as ceramsite concrete) can be used for the main body of the structure. The outer side is filled with composite insulating blocks with a thickness of more than 240mm. If necessary, 20-30mm of sprayed rigid polyurethane foam or rigid polyurethane foam insulation board can be filled between the insulating blocks and the main body. By adjusting the structure and thickness of the insulation material, the overall heat transfer coefficient is less than 0.05 W / (m²·K). This setup does not require an additional heat source and is suitable for applications ranging from 5000 to 10000 m². 3 For small to medium-sized wastewater treatment plants with a capacity of [number] treatments per day, the daily energy consumption of the electric heating tank is reduced by approximately 1200 kWh. In high-altitude, cold regions with long winters that can last up to six months, this measure is expected to save approximately 216,000 kWh of electricity annually, demonstrating significant economic benefits. Furthermore, there are virtually no associated subsequent operation and maintenance costs, and the costs associated with replacing and maintaining the electric heating equipment are avoided.

[0066] The comparison data is as follows:

[0067] In this embodiment of the invention, by using a high-efficiency insulation layer 13 (such as extruded polystyrene foam, rigid polyurethane foam, etc.), heat loss during wastewater treatment can be greatly reduced. Especially in cold and frigid regions, this insulation design ensures that the internal temperature of the system is maintained within a suitable range, enabling the treatment process to proceed stably without temperature drop due to cold weather, thus ensuring microbial activity and metabolic efficiency.

[0068] In this embodiment, the combination of the insulation layer 13 thickness and the soil cover layer 15 can effectively utilize the natural insulation effect of the soil to maintain the temperature inside the system in a long-term low-temperature environment (up to 6 months in winter), so that the sewage treatment plant can continue to operate efficiently in a low-temperature environment.

[0069] Furthermore, the activity of microorganisms decreases significantly at lower temperatures, affecting the treatment efficiency of biological treatment units (such as anaerobic tank 4 and aerobic tank 6). Insulation design ensures that the system maintains a suitable temperature (e.g., above 10°C), thereby promoting microbial growth and metabolic activity, ensuring stable wastewater treatment results, and improving pollutant removal efficiency. A stable temperature environment reduces the negative impact of temperature fluctuations on biological reactions, especially for biological treatment processes such as ammonia and phosphorus removal, significantly improving the system's treatment capacity and water quality stability.

[0070] Furthermore, the wastewater pipe 1 in the equipment layout area 11 adopts a gravity flow design, eliminating the need for an additional power source. By designing the wastewater pipe 1 to use gravity flow, wastewater can flow naturally under gravity, thus avoiding reliance on pumps or other additional power equipment. This significantly reduces operating energy consumption and electricity consumption, especially in cold regions, preventing excessive load or damage to pump equipment due to low temperatures in winter. The gravity flow design allows the system to efficiently utilize natural resources, reducing the demand for external power, lowering electricity consumption and operating costs, and resulting in significant energy-saving effects.

[0071] The slope of wastewater pipe 1 is greater than or equal to 0.5%, ensuring an appropriate flow velocity of wastewater within the pipe and preventing stagnation or backflow. A reasonable slope not only guarantees smooth wastewater flow but also effectively reduces the risk of solid deposits and blockages inside the pipe, ensuring long-term stable operation. This slope design also ensures continuous wastewater flow within the system, preventing suspended solids deposition due to excessively low flow velocity, thus reducing the frequency of subsequent cleaning and maintenance.

[0072] In operation, wastewater enters through wastewater pipe 1, undergoes preliminary pretreatment via three-stage grit chamber 2 and three-stage sedimentation tank 3, then flows into three-stage anaerobic tank 4, three-stage anoxic tank 5, and three-stage aerobic tank 6 for biological treatment. Further treatment occurs through three-stage sedimentation and three-stage filtration units, before finally entering disinfection tank 9 for disinfection and discharge. Manholes 10 are distributed throughout the system for easy personnel access. Equipment layout area 11 is located in a suitable position for placing relevant equipment. Soil covers the treatment tanks and equipment for insulation and protection. Wastewater is introduced into the treatment system via wastewater pipe 1 by gravity.

[0073] Example 2

[0074] This invention provides a procedure for setting up and maintaining wastewater treatment equipment in high-altitude and cold regions; Step 1: Site Selection Based on the local topography and sewage pipe network layout, the site selection for the sewage treatment plant is determined, and the site is leveled according to design requirements. Wastewater treatment ponds and equipment are constructed in locations with low groundwater levels that comply with urban planning regulations. The treatment structures are made of suitable concrete to ensure their strength and durability. Precise construction is carried out according to the loop-shaped layout of the treatment ponds, including the construction of three-section grit chambers (2), three-section grit chambers (3), anaerobic tanks (4), anoxic tanks (5), aerobic tanks (6), sedimentation units, filtration units, disinfection tanks (9), etc., as well as the planning and construction of the equipment layout area (11), and the reservation of manhole locations (10). In areas with excessively high groundwater levels, the sewage pipe network elevation is designed according to gravity flow requirements, lowering the design elevation of the sewage treatment plant. Process units are centrally located, and the thickness of the soil mound and cover layer (15) is rationally determined.

[0075] Step 2: Install wastewater pipes Ensure that pipe connections are tight, slopes are appropriate, and there are no leaks to guarantee that wastewater can flow smoothly between treatment units by gravity. Simultaneously, install power equipment, backwashing systems, and chemical dosing systems in equipment layout area 11, and conduct commissioning and trial runs to ensure normal equipment operation.

[0076] Step 3: Trial Run Wastewater enters the three-stage screen tank 2 through wastewater pipe 1. Debris trapped on the screen is cleaned regularly to prevent blockage. After treatment by the screen, the wastewater flows into the three-stage grit chamber 3, where grit is removed regularly to ensure the normal operation of the grit chamber 3.

[0077] The pretreated wastewater sequentially enters a three-stage anaerobic tank (4), a three-stage anoxic tank (5), and a three-stage aerobic tank (6). In anaerobic tank 4, appropriate hydraulic retention time and anaerobic environment are controlled to promote the activity of anaerobic microorganisms. In anoxic tank 5, suitable organic matter concentration and anoxic conditions are maintained to ensure the smooth progress of denitrification. In aerobic tank 6, sufficient oxygen is provided through aeration equipment to maintain the activity of aerobic microorganisms. At the same time, the aeration rate and mixed liquor recirculation ratio are adjusted according to water quality monitoring results to ensure the decomposition, nitrification, and phosphorus removal effects of organic matter.

[0078] The effluent from the three-stage aerobic tank (stage 6) enters the three-stage sedimentation unit. A portion of the settled sludge is returned to the front end of the anaerobic tank (stage 4), with the return ratio adjusted according to actual operating conditions. The remaining sludge is collected and transported for disposal periodically. The effluent from the sedimentation unit enters the three-stage filtration unit, where the filtration equipment is backwashed periodically to ensure filtration effectiveness.

[0079] The filtered wastewater enters disinfection tank 9, where an online monitoring system monitors water quality in real time, including indicators such as COD, ammonia nitrogen, total phosphorus, and fecal coliforms. Once the water quality meets standards, the discharge valve is opened for discharge; if it does not meet standards, appropriate measures are taken, such as adjusting process parameters or increasing the disinfectant dosage. The ultraviolet irradiation equipment in disinfection tank 9 is regularly maintained to ensure its normal operation and effective killing of pathogenic microorganisms.

[0080] Step Four: Maintenance and Management Phase Regularly inspect the operational status of all structures and equipment in the treatment system, including whether wastewater pipe 1 is leaking, whether the treatment tank has cracks, and whether the equipment is operating normally. Enter the system through manhole 10 to perform inspection, repair, and maintenance work, such as cleaning sediment from the bottom of the tank and replacing damaged equipment parts.

[0081] The growth of microorganisms in the biological treatment unit is monitored, and operating parameters such as nutrient dosage and aeration rate are adjusted according to changes in microbial activity and water quality to ensure stable biological treatment results. Simultaneously, the condition of the cover layer is regularly inspected, and any settlement or damage is promptly repaired to ensure its insulation and protective functions.

[0082] Perform maintenance and upkeep on the power equipment, backwashing system, and chemical dosing system in the equipment layout area 11 according to the prescribed cycle, such as replacing lubricating oil, cleaning filters, and calibrating chemical dosing equipment, to ensure long-term stable operation of the equipment, extend the service life of the equipment, and reduce operating costs.

[0083] Through the specific implementation methods of construction, operation, and maintenance management described above, the small and medium-sized sewage treatment plant system in high-altitude and cold regions of this utility model can operate efficiently and stably in low-temperature environments, achieving sewage treatment that meets standards, and has good environmental and social benefits.

[0084] Example 3

[0085] Please see Figure 1 This invention provides a wastewater treatment method for high-altitude and cold regions, comprising: Based on local air temperature, wastewater temperature, and operational requirements, the thickness of insulation layer 13 and cover layer 15 are calculated. The thickness and material selection of insulation layer 13 directly affect the system's energy efficiency and microbial activity. In cold regions, it is recommended to choose low thermal conductivity materials, such as extruded polystyrene foam or rigid polyurethane foam, with a thermal conductivity of less than 0.05 W / (m²·K), to reduce heat loss. Furthermore, the thickness of insulation layer 13 should be regularly monitored and adjusted according to changes in local air temperature and wastewater temperature to ensure the system maintains good insulation performance during cold seasons.

[0086] The thickness of the soil cover layer 15 should be greater than or equal to the maximum frost thickness (e.g., 86-120cm in Litang County). The soil cover layer 15 not only provides additional insulation but also prevents frost heave from damaging the equipment, ensuring stable operation of the system under extremely cold conditions.

[0087] The insulation design eliminates the need for an additional electric heating system to maintain the treatment tank temperature. The combination of the insulation layer 13 and the cover layer 15 is expected to result in significant energy savings, especially in cold regions where winters can last up to six months. This substantially reduces the operating costs of the electric heating equipment and minimizes maintenance requirements.

[0088] A pretreatment unit, a biological treatment unit, and an end-of-life treatment unit are arranged sequentially within the insulation zone, and the pretreatment unit, biological treatment unit, and end-of-life treatment unit are insulated by the insulation layer 13 and the soil cover layer 15. Wastewater is gradually treated through a pretreatment unit, a biological treatment unit, and an end-of-pipe treatment unit before being discharged after meeting standards.

[0089] Furthermore, the thermal conductivity of the insulation structure is less than 0.05 W / (m²·K), and the thickness of the soil cover layer 15 is greater than or equal to the maximum frost thickness.

[0090] Furthermore, the wastewater is gradually treated through a pretreatment unit, a biological treatment unit, and a final treatment unit before being discharged after meeting the standards. The process includes: the wastewater enters from the wastewater pipe 1 on the left, passes through three sections of grit chamber 2 and three sections of sedimentation tank 3 for preliminary pretreatment; then flows into three sections of anaerobic tank 4, three sections of anoxic tank 5 and three sections of aerobic tank 6 for biological treatment; then passes through three sections of sedimentation unit and three sections of filtration unit for final treatment; and finally enters disinfection tank 9 for disinfection before being discharged after meeting the standards.

[0091] This wastewater treatment method for high-altitude and cold regions ensures stable operation of the system in low-temperature environments by precisely calculating and designing the thickness of the insulation layer 13 and the soil covering layer 15, adopting a step-by-step treatment process, and optimizing the microbial growth environment. Furthermore, through energy-saving design and intelligent control, it reduces operating costs and improves treatment efficiency. Its superior economic benefits and environmental effects make it a significant advantage in wastewater treatment applications in high-altitude and cold regions.

[0092] Compared with existing wastewater treatment equipment 12 for high-altitude and cold regions, this wastewater treatment method for high-altitude and cold regions has the following significant advantages: No additional electric heating equipment is needed. Traditional wastewater treatment systems in cold regions typically require external electric heating to maintain the temperature of the treatment tank, especially in winter. However, through a precisely designed insulation layer 13 and cover layer 15, this method can naturally maintain the temperature inside the tank, avoiding reliance on electric heating equipment. This significantly reduces energy consumption, especially during the long, cold winter months, with expected savings of substantial amounts of electricity. The absence of an electric heating system also means a significant reduction in the installation, maintenance, operation, and replacement costs of electric heating equipment, resulting in a substantial decrease in long-term operating costs.

[0093] It can also enhance microbial activity and treatment efficiency. In low-temperature environments, microbial activity is inhibited, affecting wastewater treatment effectiveness. By designing a suitable insulation layer 13 and cover layer 15, the system temperature is maintained within a suitable range of 10℃ to 20℃, which is conducive to microbial growth and metabolism, ensuring the efficient operation of biological treatment units (such as anaerobic tank 4 and aerobic tank 6). A stable temperature environment enhances the microbial capacity to degrade organic matter, enabling the system to efficiently remove pollutants such as COD, ammonia nitrogen, and total phosphorus even in cold climates, ensuring that water quality meets discharge standards.

[0094] Enhancing System Stability and Reliability: In cold regions, wastewater treatment equipment 12 and pipelines are prone to frost heave due to low temperatures, leading to equipment damage. The thickness of the cover layer 15 is designed to be greater than or equal to the maximum frost thickness, effectively preventing the effects of frozen soil and protecting treatment structures and equipment from frost heave damage. This design improves system reliability and long-term stability, reducing downtime and failures. By controlling heat loss within the system, the system can operate stably under extremely cold conditions, avoiding the adverse effects of drastic temperature fluctuations on the treatment process and enhancing the system's ability to cope with harsh environments.

[0095] Improving water treatment efficiency: This method employs a step-by-step treatment process, sequentially passing wastewater through three stages: a screen tank (2), a grit chamber (3), an anaerobic tank (4), an anoxic tank (5), an aerobic tank (6), a sedimentation unit, and a filtration unit, before finally entering a disinfection tank (9) for further treatment. This staged treatment method effectively removes suspended solids, dissolved organic matter, nitrogen, phosphorus, and other pollutants from the water, ensuring that the effluent meets discharge standards. Different treatment units (such as the anaerobic tank (4) and the aerobic tank (6)) work synergistically under suitable temperature and environmental conditions, improving wastewater treatment efficiency, especially in cold regions, preventing poor biological treatment due to excessively low temperatures.

[0096] High environmental adaptability: Through insulation design and an appropriate 15mm thick soil cover, this method can effectively cope with prolonged low-temperature environments in high-altitude and cold regions, especially in areas with large temperature fluctuations. The system does not rely on external heat sources, reducing the demand for electricity, chemical agents, etc., and is more environmentally friendly.

[0097] Reduced operating costs: By lowering energy consumption, reducing equipment replacement and maintenance costs, and avoiding reliance on electric heating equipment, the system's overall operating costs are significantly lower than traditional methods. In high-altitude and cold regions, the long-term savings in energy and maintenance costs can bring considerable economic benefits.

[0098] Increased lifespan: The insulation design not only improves processing efficiency, but also extends the system's lifespan by protecting the equipment from frost heave and low temperatures, reducing equipment failures and replacement costs caused by severe weather conditions.

[0099] Compared to existing wastewater treatment equipment in high-altitude and cold regions, this method, through the combination of insulation design and wastewater treatment processes, not only operates efficiently and stably in extremely cold environments but also significantly saves energy, reduces consumption, improves treatment efficiency, extends equipment lifespan, and lowers operating costs. Its intelligent control and environmentally friendly characteristics make this method more sustainable and economically beneficial in wastewater treatment applications in high-altitude and cold regions, solving the problems of difficult operation and excessive energy consumption of traditional methods in cold climates.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wastewater treatment system for high-altitude and cold regions, characterized in that, It includes a pretreatment unit, a biological treatment unit, and an end-of-life treatment unit that are connected in sequence and set within the heat preservation zone; The pretreatment unit includes a three-section grit chamber (2) and a three-section grit chamber (3) for intercepting solid impurities and inorganic particles in the sewage step by step; the biological treatment unit consists of a three-section anaerobic tank (4), a three-section anoxic tank (5) and a three-section aerobic tank (6), and achieves organic matter degradation through the three-section anaerobic tank (4), three-section anoxic tank (5) and three-section aerobic tank (6); the end treatment unit includes a three-section sedimentation tank (7), a three-section filtration tank (8) and a disinfection tank (9) for solid-liquid separation and filtration disinfection; The top of the insulation zone is also provided with an insulation structure, which includes at least a soil cover layer (15) and an insulation layer (13). The three sections of the screen tank (2), the three sections of the grit chamber (3), the three sections of the anaerobic tank (4), the three sections of the anoxic tank (5), the three sections of the aerobic tank (6), the three sections of the sedimentation tank (7), the three sections of the filter tank (8) and the disinfection tank (9) are connected in series along the direction of sewage flow and are arranged closely together. They are arranged in a loop shape from the outside to the inside, and an equipment layout area (11) is set in the space enclosed inside the loop shape. The heights of the three-section grit chamber (2), three-section sedimentation chamber (3), three-section anaerobic chamber (4), three-section anoxic chamber (5), three-section aerobic chamber (6), three-section sedimentation chamber (7), three-section filtration chamber (8) and disinfection chamber (9) are set in a gradually decreasing manner; The aeration intensity of the three aerobic tanks (6) decreases step by step. The aeration rate of the first aerobic tank is 3-5 m3 / h, the aeration rate of the second aerobic tank is 2-3 m3 / h, and the aeration rate of the third aerobic tank is 1-2 m3 / h.

2. The wastewater treatment system for high-altitude and cold regions according to claim 1, characterized in that, The spacing between the three sections of the grid pool (2) decreases gradually, with the spacing of the first section of the grid pool being 30-50 mm, the spacing of the second section of the grid pool being 10-20 mm, and the spacing of the third section of the grid pool being 5-10 mm. The three-stage sedimentation tank (3) adopts a combination of horizontal flow sedimentation tank, aerated sedimentation tank and vortex sedimentation tank, and the separation of sand particles is achieved by hydraulic control.

3. A wastewater treatment system for high-altitude and cold regions according to claim 1, characterized in that, A sludge return channel is provided between the three anaerobic tanks (4) and the three anoxic tanks (5), and a mixed liquor return system is provided at the bottom of the three aerobic tanks (6) to return the nitrified liquor to the three anoxic tanks (5).

4. A wastewater treatment system for high-altitude and cold regions according to claim 1, characterized in that, The disinfection tank (9) is equipped with an ultraviolet disinfection device and an online water quality monitoring system, which are used to monitor COD, ammonia nitrogen, total phosphorus and fecal coliform indicators in real time, so that they meet the standards before being discharged. The three-stage filtration system consists of a sand filter, a fiber ball filter, and an activated carbon filter, with the filtration accuracy increasing by 0.5 to 1 micrometer at each stage.

5. A wastewater treatment system for high-altitude and cold regions according to claim 1, characterized in that, The insulation layer (13) is composed of 20-30mm sprayed rigid polyurethane foam and 35-45mm lightweight aggregate insulation concrete, and the thickness of the soil covering layer (15) is at least greater than 2.0m. The outer side of the insulation zone is also provided with a composite insulation block layer, the thickness of the composite insulation block layer is greater than or equal to 240mm, and a 20-30mm rigid polyurethane foam board is filled in the middle.

6. A wastewater treatment system for high-altitude and cold regions according to claim 5, characterized in that, It also includes several wastewater pipes (1); the wastewater pipes (1) in the equipment layout area (11) are designed for gravity flow and have a slope greater than or equal to 0.5%; the power equipment in the equipment layout area (11) is arranged in a centralized manner.

7. A wastewater treatment operation method for high-altitude and cold regions, employing a wastewater treatment system for high-altitude and cold regions as described in any one of claims 1-6; characterized in that, Includes the following steps: Based on the local air temperature, sewage water temperature and operation requirements, the thickness of the insulation layer (13) and the thickness of the soil covering layer (15) are calculated; A pretreatment unit, a biological treatment unit, and an end-of-life treatment unit are arranged sequentially within the insulation zone, and the pretreatment unit, biological treatment unit, and end-of-life treatment unit are insulated by an insulation layer (13) and a soil covering layer (15). Wastewater is gradually treated through a pretreatment unit, a biological treatment unit, and an end-of-pipe treatment unit before being discharged after meeting standards.

8. A wastewater treatment operation method for high-altitude and cold regions according to claim 7, characterized in that, The thermal conductivity of the insulation structure is less than 0.05 W / (m²·K), and the thickness of the soil cover layer (15) is greater than or equal to the maximum frost thickness.

9. A wastewater treatment operation method for high-altitude and cold regions according to claim 7, characterized in that, Wastewater is treated progressively through a pretreatment unit, a biological treatment unit, and a final-end treatment unit before being discharged in compliance with standards. The wastewater enters from the wastewater pipe (1) on the left and passes through three sections of grit chamber (2) and three sections of sedimentation tank (3) in sequence to complete the preliminary pretreatment; Then it flows into three anaerobic tanks (4), three anoxic tanks (5) and three aerobic tanks (6) for biological treatment; Then it is treated by three sedimentation tanks (7) and three filtration tanks (8); Finally, it enters the disinfection pool (9) and is discharged after disinfection meets the standards.

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