A low-carbon stable treatment method for rural domestic sewage in cold and arid regions based on natural energy driving

Abstract

This invention proposes a low-carbon and stable treatment method for rural domestic sewage in arid and cold regions based on natural energy, belonging to the field of water treatment technology. The sewage treatment method includes: operating and treating during non-freezing and freezing periods according to the ambient temperature characteristics. The non-freezing period is further divided into a normal temperature period and a low temperature period; during the normal temperature period, the water temperature is greater than 15℃, the hydraulic retention time is 14 hours, and the daily treatment capacity is 2.0 m³. 3 The daily processing capacity is 1.5 m³ / day, with a running time of 24 hours. During the low-temperature period, the water temperature is 0–15℃, the hydraulic retention time is 18 hours, and the daily processing capacity is 1.5 m³ / day. 3 / d, operating time is 24h; during the freezing period, when the water temperature is below 0℃, the hydraulic retention time is 16h, and the daily treatment capacity is 0.8~1.0m³. 3 / d, with a runtime of 12 hours. This invention utilizes wind-solar hybrid power generation and, through an automatic control system, manages special operating modes during non-freezing and freezing periods. Combined with insulation settings, it achieves low-energy operation and unattended maintenance of the facility, and can effectively allocate energy according to different climate characteristics and different energy production and emission characteristics, thus optimizing energy efficiency and structure.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, and in particular relates to a low-carbon and stable treatment method for rural domestic sewage in cold and arid regions based on natural energy. Background Technology

[0002] Currently, existing wastewater treatment models suffer from high operating costs due to high electricity consumption and a lack of reliable winter insulation and control measures, leading to malfunctions or even shutdowns of some treatment facilities during winter. Furthermore, wastewater treatment inevitably involves direct carbon emissions. Therefore, achieving resource recovery of effluent while maintaining low-carbon and stable operation, based on multi-objective water quality control, has become both the goal and the challenge of rural wastewater treatment.

[0003] With the rapid development of clean energy applications and automatic control system software and hardware, more and more researchers are dedicated to applying these two technologies to optimize wastewater treatment processes and reduce energy consumption and emissions. However, there are currently no reports on designing matching operation modes for the daily discharge characteristics and seasonal production and discharge patterns of rural wastewater. Summary of the Invention

[0004] Limited by the traditional sewage treatment methods and their seasonal climate and regional characteristics, this invention develops a new sewage treatment method to effectively solve the problems of high electricity costs caused by high energy consumption in some rural sewage treatment facilities and the abnormal operation or even shutdown of treatment facilities in winter due to severe cold.

[0005] This invention proposes a low-carbon and stable treatment method for rural domestic sewage in arid and cold regions based on natural energy, comprising:

[0006] Based on the environmental temperature characteristics, the operation is divided into non-freezing and freezing period treatments.

[0007] For the non-freezing period, it is divided into the normal temperature period and the low temperature period; during the normal temperature period, the water temperature is greater than 15℃, the hydraulic retention time is 14h, and the daily treatment capacity is 2.0m³. 3 The daily processing capacity is 1.5 m³ / day, with a running time of 24 hours. During the low-temperature period, the water temperature is 0–15℃, the hydraulic retention time is 18 hours, and the daily processing capacity is 1.5 m³ / day. 3 / d, runtime 24h;

[0008] During the freezing period, when the water temperature is below 0℃, the hydraulic retention time is 16 hours, and the daily treatment capacity is 0.8–1.0 m³. 3 / d, runtime is 12h.

[0009] Furthermore, the apparatus used in the processing method includes:

[0010] Wind turbines are used to collect wind energy and convert it into electrical energy.

[0011] Photovoltaic panels are used to collect solar energy and convert it into electrical energy.

[0012] Storage batteries are used to collect electrical energy transmitted by wind turbines and photovoltaic panels;

[0013] An inverter is used to convert the direct current (DC) power from a battery into alternating current (AC).

[0014] A PLC controller is used to control the output of electrical energy transmitted by the inverter;

[0015] The water treatment tank consists of an equalization tank, an anaerobic tank, an aerobic tank 1, an anoxic tank, an aerobic tank 2, a filter tank 1, and a filter tank 2, which are connected from left to right.

[0016] Septic tanks are used to hold sewage that needs to be treated.

[0017] Inlet pump 1, inlet pump 2, and inlet pump 3 are used to send sewage from the septic tank into the equalization tank; the aeration pump is used to provide aeration for aerobic tank 1 and aerobic tank 2; the inlet pump 1, inlet pump 2, inlet pump 3, and aeration pump are electrically connected to the PLC controller.

[0018] Furthermore, a wind power generation controller is provided between the wind turbine and the battery;

[0019] A photovoltaic controller is installed between the photovoltaic panel and the battery.

[0020] Furthermore, gas flow meters are installed between the aeration pump and aerobic tank one, and between the aeration pump and aerobic tank two.

[0021] Furthermore, the anaerobic tank, aerobic tank one, anoxic tank, and aerobic tank two are equipped with multifunctional combined packing material; the multifunctional combined packing material is composed of built-in volcanic rock, sponge blocks, and fiber ropes.

[0022] Furthermore, each of the equalization tank, aerobic tank one, aerobic tank two, and filtration tank two is equipped with a monitoring sensor for real-time monitoring of dissolved oxygen, conductivity, oxidation-reduction potential, and pH in the wastewater; the equalization tank is also equipped with a temperature sensor for real-time monitoring of the temperature in the wastewater.

[0023] Furthermore, the monitoring sensors in the equalization tank, aerobic tank one, aerobic tank two, and filter tank two, which are used to monitor dissolved oxygen, conductivity, oxidation-reduction potential, and pH in wastewater in real time, are electrically connected to the PLC controller.

[0024] The temperature sensor in the equalization tank, used for real-time monitoring of the wastewater temperature, is electrically connected to the PLC controller.

[0025] Furthermore, the water treatment tank is provided with an insulation heating plate on its outer side; the insulation heating plate monitors the temperature through a temperature sensor, and the insulation heating plate is electrically connected to the PLC controller;

[0026] Preferably, the outer side of the heat-insulating heating plate is provided with heat-insulating cotton.

[0027] Furthermore, the outlet end of the second filter tank is equipped with a flow-through ultraviolet sterilizer.

[0028] Furthermore, the PLC controller senses the ambient temperature through a temperature sensor in the regulating tank used to monitor the temperature of the wastewater in real time, and then controls the start of inlet pump one, inlet pump two, or inlet pump three, thereby controlling the hydraulic retention time, daily treatment capacity, and operating time.

[0029] This invention has the following advantages:

[0030] This invention employs wind-solar hybrid power generation and uses an automatic control system to manage special operating modes during non-freezing and freezing periods. Combined with insulation settings, it achieves low-energy operation and unattended operation and maintenance of the facility. Furthermore, it can effectively allocate energy according to different climate characteristics and different energy production and emission characteristics, thus optimizing energy efficiency and structure. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 This is a schematic diagram of the structure of the device described in an embodiment of the present invention;

[0033] 1. Wind turbine generator; 2. Photovoltaic power generation panel; 3. Wind power generation controller; 4. Photovoltaic controller; 5. Battery; 6. Inverter; 7. PLC controller; 8. Gas flow meter; 9. Aeration pump; 101. Inlet pump 1; 102. Inlet pump 2; 103. Inlet pump 3; 104. Septic tank; 11. Equalization tank; 12. Anaerobic tank; 13. Aerobic tank 1; 14. Anoxic tank; 15. Aerobic tank 2; 16. Filter tank 1; 17. Filter tank 2; 18. Ultraviolet sterilizer; 19. Multifunctional combined packing material; 20. Aeration assembly; 21. Filter media; 22. Mesh partition; 23. Detailed Implementation

[0034] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this invention can be combined with each other. In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to 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 invention. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; and they can be internal connections between two components. When an element is referred to as being "located" in relation to another element, it can be directly in relation to that element or may be located in an intermediate element. Those skilled in the art will understand the specific meaning of these terms in this invention through the specific circumstances.

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] One embodiment of the present invention proposes a low-carbon and stable treatment method for rural domestic sewage in arid and cold regions based on natural energy, comprising:

[0037] Based on the environmental temperature characteristics, the operation is divided into non-freezing and freezing period treatments.

[0038] For the non-freezing period, it is divided into the normal temperature period and the low temperature period; during the normal temperature period, the water temperature is greater than 15℃, the hydraulic retention time (HRT) is 14h, and the daily treatment capacity is 2.0m³. 3 The system operates for 24 hours per day; during the low-temperature period, the water temperature is 0–15℃, the hydraulic retention time (HRT) is 18 hours, and the daily treatment capacity is 1.5 m³ / day. 3 / d, runtime 24h;

[0039] During the freezing period, when the water temperature is below 0℃, the hydraulic retention time (HRT) is 16 hours, and the daily treatment capacity is 0.8–1.0 m³. 3 / d, runtime is 12h.

[0040] The generation and discharge patterns of domestic sewage vary with the seasons, with more occurring in summer and less in winter. Therefore, the system's operation cannot remain static and requires reasonable configuration. This invention, by combining an automatic control system and adjusting energy efficiency and structure, achieves a match between treated water volume and hydraulic retention time.

[0041] Based on temperature characteristics, the system is divided into non-freezing period and freezing period operation and processing.

[0042] During the non-freezing period, when the water temperature is above 15℃, the temperature is suitable for microbial growth, resulting in good biofilm activity and a better system treatment effect. Therefore, the HRT is set at 14h, and the daily treatment capacity is 2.0m³. 3 / d. During the low-temperature period, the low water temperature weakens the activity of microorganisms in the biological stage, reducing the treatment effect. Extending the hydraulic retention time (HRT) maximizes the removal of pollutants using the physical stage. Furthermore, the reduced treatment volume decreases the system's energy consumption, allowing excess electricity to be used for equipment insulation and heating to ensure stable operation. Therefore, the HRT is adjusted to 18 hours, with a daily treatment capacity of 1.5 m³ / day. 3 / d or so.

[0043] During the freezing period, when the water temperature is below 0℃, water consumption is lower in winter than in summer; therefore, the daily treatment capacity is 0.8–1.0 m³. 3 / d, HRT set to 16h, running time 12h. Compared with the normal temperature period, the removal rates of COD, ammonia nitrogen, total nitrogen and total phosphorus pollutants in the system fluctuate less during the low temperature period and the freezing period. The system as a whole is relatively stable in operation and can achieve stable and efficient removal of pollutants during the low temperature period and the freezing period.

[0044] In one embodiment of the present invention, the apparatus used in the processing method includes:

[0045] Wind turbine 1, used to collect wind energy and convert it into electrical energy;

[0046] Photovoltaic panel 2 is used to collect solar energy and convert it into electrical energy;

[0047] Battery 5 is used to collect electrical energy transmitted by wind turbine 1 and photovoltaic panel 2;

[0048] Inverter 6 is used to convert the DC power from battery 5 into AC power;

[0049] PLC controller 7 is used to control the output of electrical energy transmitted by inverter 6;

[0050] The water treatment tank consists of an equalization tank 12, an anaerobic tank 13, an aerobic tank 14, an anoxic tank 15, an aerobic tank 2 16, a filter tank 17, and a filter tank 2 18, which are connected from left to right.

[0051] Septic tank 11 is used to hold sewage to be treated;

[0052] Inlet pump 101, inlet pump 2 102, and inlet pump 3 103 are used to send sewage from septic tank 11 into equalization tank 12; aeration pump 9 is used to provide aeration for aerobic tank 14 and aerobic tank 2 16; the inlet pump 101, inlet pump 2 102, inlet pump 3 103, and aeration pump 9 are electrically connected to PLC controller 7.

[0053] In this embodiment of the invention, the inlet pumps 101, 102, and 103 have different flow rates, allowing for rapid switching during normal temperature, low temperature, and freezing periods, thereby ensuring operation according to the specified hydraulic retention time, daily processing capacity, and operating time. More specifically, the inlet pumps can be peristaltic pumps.

[0054] For example, when the effective volume of the water treatment tank is 1100L, the flow rate of the first inlet pump 101 can be 1389ml / min, the flow rate of the second inlet pump 102 can be 1042ml / min, and the flow rate of the third inlet pump 103 can be 1111ml / min.

[0055] The wind-solar hybrid power generation system proposed in this invention is based on a biophysical coupling treatment process and a thermal insulation and control system, and is matched with different climate characteristics in different seasons for operation and control strategies. The automatic control system of the device mainly consists of a wind turbine 1, a photovoltaic panel 2, a battery 5, a PLC controller 7, a water inlet pump 101, a water inlet pump 202, and a water inlet pump 303. The wind turbine 1 and the photovoltaic panel 2 respectively transmit the collected wind energy and solar energy to the battery 5 for charging. Then, the inverter 6 converts the DC power of the battery 5 into AC power required by the load. The PLC controller 7 controls the start of the water inlet pumps 101, 102, and 103 by identifying the ambient temperature, thereby realizing the adjustment of hydraulic residence time, daily processing capacity, and operating time. The specific water treatment tanks mainly include equalization tank 12, anaerobic tank 13, aerobic tank 14, anoxic tank 15, aerobic tank 2 16, filter tank 17, and filter tank 2 18. The water treatment principle of this device mainly integrates the advantages of biofilm method, activated sludge method and physical method. It utilizes the synergistic effect of microorganisms and physical technology to remove pollutants in sewage. The structure is reasonably distributed and has the characteristics of stable and high standard effluent, strong shock resistance and high applicability.

[0056] The low-carbon and stable wastewater treatment method proposed in this invention is driven by natural energy and controlled by a PLC automatic control logic system. It can basically realize online real-time monitoring and fully automated unattended operation. It can match the operation strategy of energy effective allocation with different seasonal climate characteristics and different production and discharge characteristics, and solve the problems of high energy consumption, difficult operation and maintenance, poor winter operation effect and high energy consumption and carbon emission in wastewater treatment in villages and towns in Northwest China.

[0057] This device has a wide range of applications, suitable for single-household and multi-household wastewater treatment in rural areas. It offers excellent energy-saving and consumption-reducing effects, is easy to operate and maintain, and ensures effective utilization of abundant natural energy sources while ensuring improved performance. It achieves the goal of not being limited by mains power supply and utilizing clean energy, making it significant for energy conservation and consumption reduction in the wastewater treatment field.

[0058] In one embodiment of the present invention, a wind power generation controller 3 is provided between the wind turbine generator 1 and the battery 5. The wind power generation controller 3 is used to prevent loss of control when the wind speed is too high and to prevent danger to the wind turbine when strong winds occur. Specifically, the wind turbine generator 1 is a vertical axis wind turbine generator 1.

[0059] In one embodiment of the present invention, a photovoltaic controller 4 is provided between the photovoltaic power generation panel 2 and the battery 5. The photovoltaic controller 4 is used to manage and control the energy flow between the photovoltaic panel and the battery, and mainly has charging management (avoiding overcharging or over-discharging of the battery) and protection functions (providing multiple protections such as overvoltage, overcurrent, and short circuit).

[0060] In this embodiment of the invention, the wind-solar hybrid power generation uses a storage battery 5 for energy storage, which can ensure the stability and continuity of power output. It generates and stores energy during the day, and can continue to provide a continuous and stable power supply to the load at night.

[0061] In one embodiment of the present invention, the anaerobic tank 13, aerobic tank 14, anoxic tank 15, and aerobic tank 26 are provided with multifunctional combined packing material 20.

[0062] Furthermore, the multifunctional combined packing material 20 is composed of built-in volcanic rock, sponge blocks, and fiber ropes. The outer shell of the suspended balls of the multifunctional combined packing material 20 is made of polyurethane. Depending on the mixing ratio, the combined packing material is evenly distributed at different heights in the reaction tank, ensuring uniform suspension and fluidization throughout the tank, thereby maintaining high biofilm activity. Under normal aeration intensity, the packing material is added at a quantity of 40%–50% of the reaction tank volume, and the biofilm attached to the packing material treats pollutants in the wastewater.

[0063] Furthermore, each of the equalization tank 12, aerobic tank 14, aerobic tank 16, and filtration tank 18 is equipped with sensors for real-time monitoring of dissolved oxygen, conductivity, oxidation-reduction potential, and pH in the wastewater. Specifically, these are dissolved oxygen, conductivity, oxidation-reduction potential, and pH sensors, respectively. Additionally, the equalization tank 12 is also equipped with a temperature sensor for real-time monitoring of the wastewater temperature.

[0064] Furthermore, the monitoring sensors in the equalization tank 12, aerobic tank 14, aerobic tank 2 16, and filter tank 2 18, which are used to monitor dissolved oxygen, conductivity, oxidation-reduction potential, and pH in the wastewater in real time, are all electrically connected to the PLC controller 7; the temperature sensor in the equalization tank 12, which is used to monitor the temperature in the wastewater in real time, is also electrically connected to the PLC controller 7.

[0065] Furthermore, the volume ratio of anaerobic tank 13, aerobic tank 14, anoxic tank 15, and aerobic tank 2 16 is 1:2:1.5:2.5.

[0066] In this embodiment of the invention, the equalization tank 12, anaerobic tank 13, aerobic tank 14, anoxic tank 15, aerobic tank 2 16, filter tank 17, and filter tank 2 18 are arranged in the following order: top inlet and bottom outlet, top inlet and bottom outlet, top inlet and top outlet, bottom inlet and bottom outlet, top inlet and top outlet, top inlet and bottom outlet, and finally, the treated effluent is discharged from the top. Each reaction tank is connected by a PVC (20mm) pipe. The septic tank 11 is used to hold domestic sewage.

[0067] Furthermore, the dissolved oxygen concentration in aerobic tank 14 and aerobic tank 26 is 2-4 mg / L; the dissolved oxygen concentration in anoxic tank 15 is 0-0.2 mg / L.

[0068] Furthermore, aeration components 21 are provided at the bottom of both aerobic tank 14 and aerobic tank 26. The aeration components 21 provide oxygen and agitation for the microorganisms in the aerobic tanks.

[0069] Furthermore, a gas flow meter 8 is installed between aeration pump 9 and aerobic tank 14, and between aeration pump 9 and aerobic tank 2 16.

[0070] Furthermore, the filter media 22 selected in filter tank 17 and filter tank 28 are conventional filter media such as ceramsite, zeolite, and phosphorus removal filter media 22; filter tank 17 and filter tank 28 are equipped with mesh partitions 23, and the filter media 22 is filled in nylon mesh bags and placed on the mesh partitions 23 for easy cleaning or replacement of the filter media at any time.

[0071] Furthermore, a flow-through ultraviolet sterilizer 19 is installed at the outlet of filter tank 2 18. Ultraviolet disinfection is performed using the flow-through ultraviolet sterilizer 19. The ultraviolet sterilizer 19 is a Xuelite ultraviolet sterilizer. After treatment by filter tank 1 17 and filter tank 2 18, the color and turbidity of the wastewater are reduced to a certain extent. Further disinfection by the ultraviolet sterilizer 19 further purifies the wastewater.

[0072] Furthermore, the storage battery 5 includes at least one storage battery 5; preferably, the storage battery 5 comprises 12 storage batteries 5.

[0073] In one embodiment of the present invention, an insulating heating plate is provided on the outer side of the water treatment tank. Insulating cotton is provided on the outer side of the insulating heating plate. The insulating cotton is wrapped around the four sides of the water treatment tank using a wrapping method, and the thickness of the insulating cotton is 10cm.

[0074] Furthermore, the insulation heating plate monitors the temperature via a temperature sensor and is electrically connected to the PLC controller 7. The heating mode of this insulation heating plate can be adjusted by the PLC controller 7, using high or low power heating based on the amount of power generated, to achieve stable water temperature under different scenarios and ensure the removal effect and operational stability of wastewater treatment.

[0075] In a wastewater treatment method proposed in one embodiment of the present invention, the PLC controller 7 senses the ambient temperature through a temperature sensor in the regulating tank 12 used for real-time monitoring of the temperature in the wastewater, and then controls the start of inlet pump 101, inlet pump 2 102 or inlet pump 3 103, thereby realizing the control of hydraulic retention time, daily treatment capacity and running time.

[0076] The specific implementation process of the device proposed in this invention is as follows:

[0077] Wind turbine 1 collects wind energy and converts it into electrical energy; photovoltaic panel 2 collects solar energy and converts it into electrical energy; wind turbine 1 and photovoltaic panel 2 transmit electrical energy to battery 5; inverter 6 converts the DC power from battery 5 into AC power; and PLC controller 7 controls the output of electrical energy transmitted by inverter 6.

[0078] Inlet pump 101, inlet pump 2 102, inlet pump 3 103, and aeration pump 9 are all controlled by PLC controller 7. PLC controller 7 senses the ambient temperature through a temperature sensor in the equalization tank 12, which monitors the temperature of the wastewater in real time, and then controls the start of inlet pump 101, inlet pump 2 102, or inlet pump 3 103 to control the hydraulic retention time, daily treatment capacity, and operating time. Inlet pump 101, inlet pump 2 102, or inlet pump 3 103 delivers wastewater from septic tank 11 into equalization tank 12. The water treatment tank contains, from left to right, equalization tank 12, anaerobic tank 13, aerobic tank 14, anoxic tank 15, aerobic tank 2 16, filter tank 17, and filter tank 2 18; aeration pump 9 provides aeration for aerobic tank 14 and aerobic tank 2 16.

[0079] The wastewater to be treated is processed through equalization tank 12, anaerobic tank 13, aerobic tank 14, anoxic tank 15, aerobic tank 2 16, filter tank 17, and filter tank 2 18, and then discharged after ultraviolet disinfection by flow-type ultraviolet sterilizer 19.

[0080] Water quality testing showed that the treated wastewater consistently met the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants". It meets the Class B standard and can be discharged directly. The effluent can be used for ecological water replenishment, greening irrigation, toilet flushing and reuse, etc.

[0081] Under the control of PLC controller 7, the electrical energy generated by the power generation system (wind turbine 1, photovoltaic power generation panel 2) can be stably distributed to each reaction condition, and the switching between each condition is smooth, so that the load can make the most of the electrical energy generated by the power generation system.

[0082] Example 1: A low-carbon and stable treatment method for rural domestic sewage in arid and cold regions based on natural energy.

[0083] The apparatus used in this method is:

[0084] In one embodiment of the present invention, the apparatus used in the processing method includes:

[0085] Wind turbine 1, used to collect wind energy and convert it into electrical energy;

[0086] Photovoltaic panel 2 is used to collect solar energy and convert it into electrical energy;

[0087] Battery 5 is used to collect electrical energy transmitted by wind turbine 1 and photovoltaic panel 2; specifically, there are 12 batteries 5.

[0088] A wind power generation controller 3 is provided between the wind turbine 1 and the battery 5;

[0089] A photovoltaic controller 4 is provided between the photovoltaic power generation panel 2 and the storage battery 5;

[0090] Inverter 6 is used to convert the DC power from battery 5 into AC power;

[0091] PLC controller 7 is used to control the output of electrical energy transmitted by inverter 6;

[0092] The water treatment tank consists of an equalization tank 12, an anaerobic tank 13, an aerobic tank 14, an anoxic tank 15, an aerobic tank 2 16, a filter tank 17, and a filter tank 2 18, which are connected from left to right.

[0093] Septic tank 11 is used to hold sewage to be treated;

[0094] Inlet pump 101, inlet pump 2 102, and inlet pump 3 103 are used to send sewage from septic tank 11 into equalization tank 12; aeration pump 9 is used to provide aeration for aerobic tank 14 and aerobic tank 2 16.

[0095] The system includes a water inlet pump 101, a water inlet pump 2 102, a water inlet pump 3 103, and an aeration pump 9. The water inlet pump 101, water inlet pump 2 102, water inlet pump 3 103, and aeration pump 9 are electrically connected to the PLC controller 7.

[0096] The water treatment tank has an effective volume of 1100L, the flow rate of the first inlet pump 101 is 1389ml / min, the flow rate of the second inlet pump 102 is 1042ml / min, and the flow rate of the third inlet pump 103 is 1111ml / min.

[0097] The anaerobic tank 13, aerobic tank 14, anoxic tank 15, and aerobic tank 26 are equipped with multifunctional combined packing material 20. The multifunctional combined packing material 20 is composed of built-in volcanic rock, sponge blocks and fiber ropes, and the outer shell of the suspended ball of the multifunctional combined packing material 20 is made of polyurethane.

[0098] Each of the equalization tank 12, aerobic tank 14, aerobic tank 2 16, and filtration tank 2 18 is equipped with a monitoring sensor for real-time monitoring of dissolved oxygen, conductivity, oxidation-reduction potential, and pH in the wastewater.

[0099] The monitoring sensors in equalization tank 12, aerobic tank 14, aerobic tank 2 16, and filter tank 2 18, which are used to monitor dissolved oxygen, conductivity, oxidation-reduction potential, and pH in wastewater in real time, are electrically connected to PLC controller 7; the temperature sensors in equalization tank 12, which are used to monitor the temperature in wastewater in real time, are all electrically connected to PLC controller 7.

[0100] Aeration components 21 are installed at the bottom of both aerobic tank 14 and aerobic tank 2 16. Gas flow meters 8 are installed between aeration pump 9 and aerobic tank 14, and between aeration pump 9 and aerobic tank 2 16.

[0101] The filter media 22 selected in filter tank 17 and filter tank 28 are conventional filter media 22 such as ceramsite, zeolite, and phosphorus removal filter media 22; Filter tank 17 and filter tank 28 are equipped with mesh partitions 23, and the filter media 22 are filled in nylon mesh bags and placed on the mesh partitions 23 for easy cleaning or replacement of the filter media at any time.

[0102] The outlet of filter tank 2 (18) is equipped with a flow-through ultraviolet sterilizer (19). Ultraviolet disinfection is performed using the flow-through ultraviolet sterilizer (19). The ultraviolet sterilizer (19) is a Xueleit ultraviolet sterilizer (19).

[0103] The water treatment tank is equipped with an insulation heating plate on its outer side. The insulation heating plate is covered with insulation cotton. The insulation cotton is wrapped around all four sides of the water treatment tank using a wrapping method, and the insulation cotton is 10cm thick. The insulation heating plate monitors the temperature via a temperature sensor and is electrically connected to the PLC controller 7.

[0104] Specific processing methods include:

[0105] For rural domestic sewage in Northwest China, a demand-based wastewater treatment system consisting of a two-stage A / O (air / water exchange) system, physical filtration, and disinfection was constructed. Considering the unique characteristics of Northwest China, such as long hours of sunshine and high wind speeds, a wind-solar hybrid power generation system was used to power the system. This treatment equipment is designed to serve 15-20 households, with 3 people per household, for a total population of 45-60. Based on a per capita wastewater discharge of 30L / day (the specific volume will vary depending on temperature and time of day), the designed treatment capacity is 2.0m³. 3 / d, the effective volume of the equipment is 1100L, and the anaerobic tank 13, aerobic tank, anoxic tank 15, and aerobic tank are designed in a ratio of 1:2:1.5:2.5.

[0106] The water quality indicators and physicochemical indicators of the system influent are shown in Table 1 and Table 2.

[0107] Table 1. System Influent Water Quality Indicators

[0108]

[0109] Table 2. Physicochemical Indicators of the System Influent

[0110]

[0111] Considering the fact that rural water consumption is much lower in winter than in summer, and to ensure the normal operation of the treatment facilities under extreme low-temperature conditions, the operating modes for non-freezing and freezing periods are shown in Table 3.

[0112] For the freezing period, the HRT (Heat Retention Time) is designed to be 16 hours, with a daily processing capacity of 0.8–1.0 m³. 3 / d.

[0113] For non-freezing periods, the system is divided into normal temperature (>15℃) and low temperature (0~15℃) periods, depending on the specific water temperature. During the normal temperature period, the HRT of the equipment is adjusted to 14h, and the daily processing capacity is 2.0m³. 3 / d; During the low-temperature period, the low water temperature weakens the activity of microorganisms in the biological section, reducing the treatment effect. Therefore, the hydraulic retention time (HRT) is extended to maximize the removal of pollutants in the physical section, ensuring stable equipment operation. Thus, during the low-temperature period, the HRT is adjusted to 18 hours, with a daily treatment capacity of 1.5 m³. 3 Approximately / d. The COD in the system's effluent is... Cr NH4 + -N, TN, TP, SS, and pH meet the "Pollutant Discharge Standard for Municipal Wastewater Treatment Plants" The Level 1B standard.

[0114] Table 3 Operating Parameters

[0115]

[0116] The average results of water quality testing are shown in Table 4 below.

[0117] Table 4. Average Water Quality Test Results (Unit: ml / L)

[0118]

[0119] In rural areas of Northwest China, the average daily wastewater discharge per person during the non-freezing period (normal temperature period) is 30 L / d. The equipment operates continuously and efficiently 24 hours a day, with effluent COD and NH4 levels... + The concentrations of -N, TN, TP, and SS meet the requirements of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants". The water quality meets the Class B standard. In rural areas of Northwest China, during the non-freezing period (low temperature period), the average daily drainage volume per person is 25L / d. With the equipment operating continuously for 24 hours a day, the concentration of the effluent can meet the Class B standard. During the freezing period in rural areas of Northwest China, the average daily drainage volume per person is 15L / d. During this period, the equipment operates for 12 hours during the day, and at night, the electricity is prioritized for heat preservation and heating. The concentration of the effluent can also basically meet the Class B standard.

[0120] Table 5. Fecal coliform count (CFU / L) in influent and effluent wastewater

[0121]

[0122] According to the data in the table above, after ultraviolet disinfection by the sewage treatment system, the average reduction rate of fecal coliform bacteria in the sewage was 98.72%, and the effluent met the "Discharge Standard of Pollutants for Urban Sewage Treatment Plants". The Class A emission standard for fecal coliforms is 10 3 per L.

[0123] Table 6 Comparison of Removal Rates of Various Pollutants by Reactors at Different Stages

[0124]

[0125] Based on a biophysical coupled treatment process and a self-controlled air extraction system, the system employs operational control strategies for different seasons and climatic characteristics. Compared to normal temperature periods, the removal rates of COD, ammonia nitrogen, total nitrogen, total phosphorus, and suspended solids fluctuate within a range of [-4.19%, +3.33%] during low-temperature and freezing periods. COD removal rate shows a slight increase, while TP removal rate shows a slight decrease. The system as a whole operates relatively stably, achieving stable and efficient removal of pollutants during low-temperature and freezing periods. Simultaneously, it effectively solves the problem of winter effluent treatment from underground wastewater treatment equipment in Northwest China.

[0126] In addition, the system's power generation is detected and recorded by corresponding electronic sensors and a PLC (FX2N-40M, Tianjin Jiachuang Technology Development Co., Ltd., China), while power consumption is recorded in real time by an electricity meter. Based on power generation and consumption, the capacity utilization rate is calculated to be 90.63 ± 10.14%.

[0127] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-carbon and stable treatment method for rural domestic sewage in arid and cold regions based on natural energy, characterized in that, include: Based on the environmental temperature characteristics, the operation is divided into non-freezing and freezing period treatments. For the non-freezing period, it is divided into the normal temperature period and the low temperature period; during the normal temperature period, the water temperature is greater than 15℃, the hydraulic retention time is 14 hours, and the daily treatment capacity is 2.0 m³. 3 The system operates for 24 hours per day; during the low-temperature period, the water temperature is 0~15℃, the hydraulic retention time is 18 hours, and the daily treatment capacity is 1.5 m³ / day. 3 / d, runtime 24 h; During the freezing period, when the water temperature is below 0℃, the hydraulic retention time is 16 hours, and the daily treatment capacity is 0.8~1.0 m³. 3 / d, runtime 12h; The apparatus used in the processing method includes: Wind turbine (1) is used to collect wind energy and convert it into electrical energy; Photovoltaic power generation panel (2) is used to collect light energy and convert it into electrical energy; A storage battery (5) is used to collect electrical energy transmitted by the wind turbine (1) and the photovoltaic panel (2); Inverter (6) is used to convert the DC power from the storage battery (5) into AC power; PLC controller (7) is used to control the output of electrical energy transmitted by inverter (6); The water treatment tank consists of an equalization tank (12), an anaerobic tank (13), an aerobic tank one (14), an anoxic tank (15), an aerobic tank two (16), a filter tank one (17), and a filter tank two (18) connected from left to right. Septic tank (11), used to hold sewage to be treated; Inlet pump 1 (101), inlet pump 2 (102), and inlet pump 3 (103) are used to send sewage from septic tank (11) into regulating tank (12); aeration pump (9) is used to provide aeration for aerobic tank 1 (14) and aerobic tank 2 (16); the inlet pump 1 (101), inlet pump 2 (102), inlet pump 3 (103), and aeration pump (9) are electrically connected to PLC controller (7); The regulating tank (12) is also equipped with a temperature sensor for real-time monitoring of the temperature in the wastewater; the temperature sensor in the regulating tank (12) for real-time monitoring of the temperature in the wastewater is electrically connected to the PLC controller (7); the PLC controller (7) senses the ambient temperature through the temperature sensor in the regulating tank (12) for real-time monitoring of the temperature in the wastewater, and then controls the start of the first inlet pump (101), the second inlet pump (102) or the third inlet pump (103), thereby realizing the control of hydraulic retention time, daily treatment capacity and running time.

2. The processing method according to claim 1, characterized in that, A wind power generation controller (3) is provided between the wind turbine (1) and the battery (5); A photovoltaic controller (4) is provided between the photovoltaic power generation panel (2) and the storage battery (5).

3. The processing method according to claim 1, characterized in that, Gas flow meters (8) are installed between the aeration pump (9) and aerobic tank one (14), and between the aeration pump (9) and aerobic tank two (16).

4. The processing method according to claim 1, characterized in that, The anaerobic tank (13), aerobic tank one (14), anoxic tank (15), and aerobic tank two (16) are equipped with multifunctional combined packing material (20); the multifunctional combined packing material (20) is composed of built-in volcanic rock, sponge blocks and fiber ropes.

5. The processing method according to claim 1, characterized in that, Each of the regulating tank (12), aerobic tank one (14), aerobic tank two (16), and filtration tank two (18) is equipped with a monitoring sensor for real-time monitoring of dissolved oxygen, conductivity, oxidation-reduction potential, and pH in the wastewater.

6. The processing method according to claim 5, characterized in that, The monitoring sensors in the equalization tank (12), aerobic tank one (14), aerobic tank two (16), and filter tank two (18) for real-time monitoring of dissolved oxygen, conductivity, oxidation-reduction potential, and pH in wastewater are electrically connected to the PLC controller (7).

7. The processing method according to claim 1, characterized in that, The water treatment tank is provided with an insulation heating plate on the outside; the insulation heating plate monitors the temperature through a temperature sensor and is electrically connected to the PLC controller (7).

8. The processing method according to claim 7, characterized in that, The outer side of the heat-insulating heating plate is provided with heat-insulating cotton.

9. The processing method according to claim 1, characterized in that, The outlet of the second filter tank (18) is equipped with a flow-through ultraviolet sterilizer (19).

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