A rural household domestic sewage treatment device, treatment method and construction method

Abstract

The invention discloses a rural household domestic sewage treatment device, comprising a manure inlet pipe, a septic unit, a coarse filter unit and a tower-type biological filter unit, wherein the septic unit, the coarse filter unit and the tower-type biological filter unit are sequentially connected through a pipeline, and the discharge port of the manure inlet pipe is connected to the inside of the septic unit. The invention has the beneficial effects of stable operation, being unaffected by seasonal temperature changes, strong impact resistance, low energy consumption (60 yuan / year), low operation failure rate, unattended operation and simple maintenance.

Description

Technical Field

[0001] The invention relates to an improvement of a sewage treatment device, in particular to a rural household domestic sewage treatment device, a treatment method and a construction method. Background Art

[0002] Domestic sewage discharged by rural residents includes human feces and urine, as well as washing, bathing and kitchen wastewater. Compared with urban domestic sewage, rural domestic sewage has the characteristics of scattered distribution, relatively high pollutant concentration and large differences in water volume.

[0003] At present, there are three major characteristics of rural domestic sewage in my country:

[0004] (1) Large overall water volume;

[0005] (2) The types are complex, and the emission intensity and patterns vary greatly across regions;

[0006] (3) Rural environmental construction is not in sync with economic development, the treatment rate is low, and pollution is serious.

[0007] (4) The carbon-to-wastewater nitrogen ratio is low, making operation difficult.

[0008] At present, centralized collection and centralized treatment are widely adopted in rural sewage, and biological contact oxidation, A / O, biological rotary table and other processes are mostly adopted. It is necessary to lay a large number of drainage pipelines according to the local terrain, living range, living habits and other factors in the rural areas, which consumes a lot of investment costs. Summary of the invention

[0009] The purpose of the present invention is to solve the above problems and to design a rural household domestic sewage treatment device, treatment method and construction method.

[0010] To achieve the above-mentioned purpose, the technical solution of the present invention is a rural household domestic sewage treatment device, comprising a manure inlet pipe, a septic unit, a coarse filter unit and a tower-type biological filter unit, wherein the septic unit, the coarse filter unit and the tower-type biological filter unit are sequentially connected through pipelines, and the discharge port of the manure inlet pipe is connected to the inside of the septic unit; the septic unit is used for preliminary treatment of domestic sewage, degrading solids and sludge in the sewage into soluble substances, and decomposing macromolecular organic matter into small molecular substances, and the septic unit filters out primary sewage;

[0011] The coarse filtration unit is used to filter the primary sewage, perform anaerobic digestion on the solid matter in the primary sewage, and filter out the secondary sewage;

[0012] The tower biological filtration unit is used to filter the secondary sewage, attach pollutants and bacteria in the secondary sewage, filter out clean water from the tower biological filtration unit, and the clean water flows out of the tower biological filtration unit from the drainage system.

[0013] Preferably, the septic unit comprises a septic tank, a first partition, a second partition, a first folding tube, and a second folding tube, wherein:

[0014] The septic tank is pre-buried in the foundation pit, and a first partition and a second partition are provided inside the septic tank;

[0015] The first partition and the second partition divide the inner cavity of the septic tank into a primary anaerobic chamber, a secondary anaerobic chamber, and a clarification chamber which are not interconnected;

[0016] A first folded pipe is provided in the first anaerobic chamber, and the water outlet end of the first folded pipe penetrates the first baffle and enters the second anaerobic chamber. The first folded pipe is used to block the scum in the upper layer and the bottom sludge in the first anaerobic chamber, and the relatively clear sewage in the middle layer of the first anaerobic chamber enters the second anaerobic chamber;

[0017] A second folded pipe is provided in the secondary anaerobic chamber, and the water outlet end of the second folded pipe passes through the second partition plate and enters the clarification chamber. The second folded pipe is used to block the scum in the upper layer and the bottom sludge in the secondary anaerobic chamber, and the relatively clear sewage in the middle layer of the secondary anaerobic chamber enters the clarification chamber.

[0018] Preferably, an exhaust port is formed on the upper surface of the septic tank, and the exhaust port is connected to the primary anaerobic chamber, and the exhaust port is used to exhaust the odor of the primary anaerobic chamber of the septic tank.

[0019] Preferably, a slag discharge port is formed on the upper surface of the septic tank, and the slag discharge port is connected to the primary anaerobic chamber. The slag discharge port is used to regularly and manually discharge the indecomposable feces in the septic tank. An observation port is formed on the upper surface of the septic tank, and the observation port is connected to the clarification chamber.

[0020] Preferably, the plane where the water inlet of the first folded tube is located is lower than the plane where the water inlet of the second folded tube is located, and the sewage in the middle layer of the first anaerobic chamber enters the secondary anaerobic chamber through the first folded tube for further anaerobic digestion to degrade the solids in the sewage, and the sewage in the middle layer of the secondary anaerobic chamber enters the clarification chamber through the second folded tube.

[0021] Preferably, the coarse filtration unit comprises a coarse filtration shell, a water inlet, a water outlet, an upper filter material layer, and a lower filter material layer, wherein the first surface of the coarse filtration shell forms a water inlet, and the second surface of the coarse filtration shell forms a water outlet, and the interior of the coarse filtration unit is provided with an upper filter material layer and a lower filter material layer, which filter the sewage in the clarification chamber and anaerobically digest and decompose the intercepted solid matter again, ensuring that the effluent of the coarse filtration unit contains substantially no suspended solids, thereby reducing the processing load of the subsequent tower biological filtration unit.

[0022] Preferably, it further comprises a reflux unit, which comprises a three-way valve, a first water pipe, a second water pipe and a reflux pipe, wherein:

[0023] A pair of branch pipes of the three-way valve are respectively connected to the first water pipe and the second water pipe;

[0024] The main pipe of the three-way valve is connected to the return pipe;

[0025] The first water pipe is connected to the drainage pump;

[0026] The second water pipe is connected to an outdoor sewer;

[0027] The reflux pipe extends into the clarification chamber.

[0028] A first float valve is provided at the water outlet of the reflux pipe.

[0029] In the return unit, the sewage from the septic tank will enter the coarse filter unit through the clarification chamber, and then enter the tower biological filter unit, causing the overall liquid level of the septic tank to drop. When the drainage pump is started, the drainage will first flow back to the clarification chamber of the septic tank. When the liquid level in the clarification chamber is at the upper limit of the float valve, the drainage stops flowing back, and the rest is discharged to the outdoor sewer.

[0030] A method for treating rural household sewage, the method comprising the following steps:

[0031] Step 1: Domestic sewage enters the septic tank and is separated and precipitated by gravity to form primary sewage;

[0032] Step 2: The primary sewage is coarsely filtered, and the intercepted solid matter is anaerobically digested and decomposed to form secondary sewage;

[0033] Step 3: Biochemical filtration of secondary sewage to attach pollutants to the surface of the filter material to form clear water:

[0034] Step 4: By limiting the liquid level in the clarification chamber through the liquid level valve of the reflux device, the water inlet of the tower biological filtration unit 24 is maintained, so that the device generally takes up less space and is easy to install in rural households. There is no need to use aeration equipment, thus avoiding problems such as high energy consumption, aeration head blockage, aeration equipment and sludge pump failure. Moreover, there is no need for inspection personnel to inspect the equipment regularly, and the equipment failure repair and maintenance rate is lower.

[0035] A construction method for a rural household sewage treatment device, the method comprising the following steps:

[0036] Step 1: Level the ground;

[0037] Step 2: Digging the land;

[0038] Step 3: Pre-bury the septic tank underground;

[0039] Step 4: The septic tank, the coarse filter unit and the biological filter are connected by pipes;

[0040] Step 5: The return end of the return unit extends into the clarification chamber of the septic tank, meeting the domestic sewage treatment needs of all rural areas in southern and northern China, and is suitable for treating sewage generated by the normal life of 0-8 adults in the family.

[0041] Beneficial Effects

[0042] A rural household sewage treatment device manufactured by the technical solution of the present invention has the following technical effects:

[0043] 1. Septic tank: The septic tank receives sewage from all household activities such as flushing toilets, washing clothes, bathing, and cooking. After more than 24 hours of anaerobic decomposition, it is convenient for subsequent treatment units. The solids and sludge in the sewage are degraded into soluble substances by using the principles of sedimentation and anaerobic fermentation, and the macromolecular organic matter that is difficult to decompose is further converted into small molecules, which enhances the clarity of the effluent. The sewage is treated by the primary anaerobic chamber, the secondary anaerobic chamber, the clarification chamber, and the coarse filtration unit, and almost all the suspended solids in the water are intercepted and anaerobically decomposed;

[0044] 2. Rough filtration unit: Through the filtration of the upper and lower layers of filter media in the rough filtration unit, extremely tiny suspended solids can be intercepted and decomposed, especially more solids and difficult-to-degrade macromolecules in the sewage can be degraded. In addition, since the proportion of carbon sources in solids is generally high, the carbon-nitrogen ratio in the sewage is increased, which is helpful for the subsequent microbial unit to treat the sewage;

[0045] 3. Tower biological filtration unit, as the water inlet of the tower biological filtration unit, first passes through the flow control device, which controls the sewage to enter the water distributor of the tower biological filtration unit at a fixed flow rate, and the water distributor evenly distributes the sewage on the filter material;

[0046] 4. Reflux unit: the float valve is set above the liquid level in the clarification chamber of the septic tank. A high limit of the liquid level is set for the float valve to control the reflux. When the liquid level in the clarification chamber of the septic tank reaches the set high limit, the float of the float valve floats up to block the reflux. The reflux clean water has a high oxygen content, which causes denitrification in the third compartment of the septic tank, achieving the effect of pre-denitrification to remove total nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural schematic diagram of a rural household domestic sewage treatment device according to the present invention;

[0048] Figure 2 It is a structural schematic diagram of the tower type biological filtration unit of the present invention;

[0049] Figure 3 is a first partial enlarged schematic diagram of the tower type biological filtration unit of the present invention;

[0050] Figure 4 is a second partial enlarged schematic diagram of the tower type biological filtration unit of the present invention;

[0051] Figure 5 It is a flow chart of the steps of a rural household sewage treatment method according to the present invention;

[0052] Figure 6 It is a flowchart of the steps of the construction method of a rural household sewage treatment device according to the present invention;

[0053] In the figure, 1, manure inlet pipe; 3, septic tank; 4, first baffle; 5, second baffle; 6, first folded pipe; 7, second folded pipe; 8, primary anaerobic chamber; 9, secondary anaerobic chamber; 10, clarification chamber; 11, exhaust port; 12, slag discharge port; 13, observation port; 14, coarse filter housing; 15, water inlet; 16, water outlet; 17, upper filter material layer; 18, lower filter material layer; 19, three-way valve; 20, first water pipe; 21, second water pipe; 22, return pipe; 23, first float valve; 24. Tower-type biological filtration unit; 41. Filter tank shell; 42. First water inlet; 43. Liquid level meter; 44. First water storage tank; 45. Second water storage tank; 46. Second float valve; 47. Second water inlet; 48. Second water outlet; 49. Universal pipe; 410. First water pipe; 411. Flat water distributor; 412. Sewage filling tower; 413. Water collecting tank; 414. Cover plate; 415. Exhaust pipe; 416. Air inlet pipe; 417. Second water pipe; 418. Drain pump. DETAILED DESCRIPTION

[0054] Embodiment 1, as Figures 1 to 3 As shown,

[0055] The present invention is described in detail below in conjunction with the accompanying drawings. A rural household domestic sewage treatment device includes a fecal inlet pipe 1, a septic unit, a coarse filter unit and a tower biological filter unit 24. The septic unit, the coarse filter unit and the tower biological filter unit are connected in sequence through pipelines, and the discharge port of the fecal inlet pipe 1 is connected to the inside of the septic unit; the septic unit is used for preliminary treatment of domestic sewage, degrading solids and sludge in the sewage into soluble substances, and decomposing macromolecular organic matter into small molecular substances, and the septic unit filters out primary sewage; the coarse filter unit is used for filtering primary sewage, performing anaerobic digestion reaction on solid substances in the primary sewage, and filtering out secondary sewage; the tower biological filter unit 24 is used for filtering secondary sewage, reducing the pollutant content in the secondary sewage, and the tower biological filter unit 24 filters out clean water, and the clean water is discharged from the tower biological filter unit 24 by a drainage pump and discharged into an outdoor sewer.

[0056] In the present technical solution, the coarse filter unit is a separate filtering device. In order to save space, it can be combined with the clarification chamber 10 of the septic tank 1. The coarse filter unit is directly placed inside the clarification chamber 10, and the manure inlet pipe 1 is connected to the inside of the primary anaerobic chamber of the septic tank 3. The water inlet 15 of the coarse filter housing 14 in the clarification chamber 10 of the septic tank 3 is lower than the sewage liquid level inside the clarification chamber 10, and the water outlet 16 of the coarse filter housing 14 is connected to the inside of the tower biological filtration unit 24 through a pipeline.

[0057] In this technical solution, the septic tank 1 receives all household sewage generated by flushing wastewater, laundry, bathing, cooking, etc., and undergoes anaerobic decomposition for more than 24 hours to facilitate subsequent coarse filtration unit treatment. The septic tank 1 utilizes the principles of sedimentation and anaerobic fermentation to degrade the solids and sludge in the above sewage into soluble substances, and further converts the difficult-to-decompose macromolecular organic matter into small molecular substances. The septic tank 1 is provided with a first partition 4 and a second partition 5, respectively.

[0058] The first partition 4 blocks the scum and bottom sludge in the upper layer of the primary anaerobic chamber 8, and the relatively clear sewage in the middle layer of the primary anaerobic chamber 8 enters the secondary anaerobic chamber 9. The second partition 5 blocks the scum and bottom sludge in the upper layer of the secondary anaerobic chamber 9, and the relatively clear sewage in the middle layer of the secondary anaerobic chamber 9 enters the clarification chamber 10. All sewage enters the primary anaerobic chamber 8 of the septic tank 3 from the manure inlet pipe 1, and the feces and solids in the sewage settle to the bottom for anaerobic digestion. The middle layer of the primary anaerobic chamber 8 enters the secondary anaerobic chamber 9 through the first folded pipe 6 for further anaerobic digestion to degrade the solids in the sewage. The middle layer sewage of the secondary anaerobic chamber 9 enters the clarification chamber 10 through the second folded tube 7; the coarse filtration unit is used to filter the sewage in the clarification chamber 10, and digest and decompose the intercepted solid matter again through anaerobism, so as to ensure that the effluent of the coarse filtration unit basically does not contain suspended solids, and reduce the processing load of the tower biological filtration unit behind. The coarse filtration unit includes a water inlet 15, a water outlet 16, and is filled with an upper filter material layer 17 and a lower filter material layer 18. The upper filter material layer 17 is a low-density filter material, which is used to adsorb and intercept the suspended solids in the sewage, so that the suspended solids are digested and decomposed by anaerobism in the low-density filter material; the lower filter material layer 18 is a high-density filter material, which is used to intercept the tiny suspended solids remaining in the sewage again, and the coarse filtration unit is still in an anaerobic state, digesting and decomposing the tiny suspended solids. In addition, the coarse filtration unit is an enhanced anaerobic unit, which can degrade more difficult-to-degrade macromolecules into small molecules.

[0059] The effluent from the clarification chamber 10 of the septic tank 3 enters the upper filter layer 17 and the lower filter layer 18 of the coarse filtration unit in sequence through pipes, which can remove all extremely tiny suspended solids therein. Moreover, because the proportion of carbon sources in solids is generally high, the coarse filtration unit also increases the carbon and nitrogen in the sewage. The effluent from the coarse filtration unit is discharged from the outlet of the clarification chamber 10 of the septic tank 3 and enters the tower biological filtration unit.

[0060] The septic unit includes a septic tank 3, a first partition 4, a second partition 5, a first folded pipe 6, and a second folded pipe 7, wherein the septic tank 3 is pre-buried in a foundation pit, and a first partition 4 and a second partition 5 are arranged inside the septic tank 3; the first partition 4 and the second partition 5 divide the inner cavity of the septic tank 3 into a primary anaerobic chamber 8, a secondary anaerobic chamber 9, and a clarification chamber 10 which are not connected to each other; the first anaerobic chamber 8 is provided with a first folded pipe 6, and the water outlet end of the first folded pipe 6 passes through the first partition 4 to enter the secondary anaerobic chamber 9; the secondary anaerobic chamber 9 is provided with a second folded pipe 7, and the water outlet end of the second folded pipe 7 passes through the second partition 5 to enter the clarification chamber 10.

[0061] An exhaust port 11 is formed on the upper surface of the septic tank 3 , and the exhaust port 11 is connected to the primary anaerobic chamber 8 .

[0062] A slag discharge port 12 is formed on the upper surface of the septic tank 3 , and the slag discharge port 12 is connected to the primary anaerobic chamber 8 . An observation port 13 is formed on the upper surface of the septic tank 3 , and the observation port 13 is connected to the clarification chamber 10 .

[0063] The plane where the water inlet of the first folded tube 6 is located is lower than the plane where the water inlet of the second folded tube 7 is located.

[0064] The coarse filter unit includes a coarse filter housing 14, a water inlet 15, a water outlet 16, an upper filter material layer 17, and a lower filter material layer 18, wherein the first surface of the coarse filter housing 14 forms the water inlet 15, and the second surface of the coarse filter housing 14 forms the water outlet 16. The interior of the coarse filter unit is provided with an upper filter material layer 17 and a lower filter material layer 18. The effluent of the coarse filter unit is used as the inlet of the tower biological filtration unit. It first passes through a flow control device. The flow control device controls the sewage to enter the water distributor of the tower biological filtration unit at a fixed flow rate. The water distributor evenly distributes the sewage on the filter material. The sewage passes through each level of the filter material unit. The filter material is divided into 5 units in total, numbered 1 / 2 / 3 / 4 / 5 from top to bottom. The filter material in the filter material unit is mainly suspended ball biological filler. The filling gap of the suspended ball biological filler is appropriately filled with polyurethane foam filler. The filter material in the filter material unit is completely filled with polyurethane foam filler. The filter unit is divided into two layers. The upper filter unit number 1 / 2 is the same and is completely filled with polyurethane foam filler, and the lower filter unit 3 / 4 is completely filled with MBBR filler. Filter unit 5 is completely filled with quartz sand.

[0065] In the present technical solution, the reflux unit includes a three-way valve 19, a first water pipe 20, a second water pipe 21 and a reflux pipe 22, wherein a pair of branch pipes of the three-way valve 19 are connected to the first water pipe 20 and the second water pipe 21 respectively; the main pipe of the three-way valve 19 is connected to the reflux pipe 22; the first water pipe 20 is connected to the outdoor sewer; the reflux pipe 22 extends into the clarification chamber 10, and a first float valve 23 is provided at the outlet of the reflux pipe 22, the first float valve 23 is arranged above the liquid level of the clarification chamber 10 of the septic tank 3, and a liquid level upper limit for controlling the reflux is set for the first float valve 23. When the liquid level of the clarification chamber 10 of the septic tank 3 reaches the set upper limit, the float of the first float valve 23 floats up to block the reflux. Normally, the sewage of the septic tank 3 will enter the coarse filtration unit through the clarification chamber 10, and then enter the tower biological filtration unit, causing the overall liquid level of the septic tank 3 to drop. When the drainage pump 418 is started, the clean water in the water collection tank (the drainage at this time is the treated clean water, which has met the discharge standards and is no longer sewage) will first flow back to the clarification chamber 10 of the septic tank 3. When the liquid level in the clarification chamber 10 is at the upper limit of the first float valve 23, the clean water stops flowing back, and the remaining clean water is discharged to the outdoor sewer.

[0066] In the present technical scheme, the second float valve 46 in the tower biological filtration unit 24 controls the water inflow. First, the second float valve 46 is set at a certain water inflow high limit. When the liquid level reaches this high limit, the float ball of the second float valve 46 rises to control no more water inflow. When the liquid level drops slightly, the first water conduit 410 through the first water inlet 42 will replenish water in time. The water outlet height of the universal pipe 49 of the flow control device is set near the high limit of the second float valve 46, and the height of the water outlet is adjustable at will. When the water outlet height is lower than the float ball high limit of the second float valve 46, the water outlet will continuously discharge water. When the water outlet is slowly raised, the water outlet flow rate of the water outlet will gradually decrease until the water outlet is no longer lower than the high limit. When the water outlet is raised again, the water outlet will not discharge water. Therefore, according to the height difference between the water outlet and the float ball high limit of the second float valve 46, the required water inflow of the tower biological filtration unit can be determined.

[0067] In the present technical solution, the tower-type biological filtration unit 24 is installed under the ground surface, and enters the first water tank 44 of the sewage flow control unit inside the filter tank shell 41 through the first water inlet 42, the first water conduit 410, and the second water inlet 47 in sequence. Since the second float valve 46 in the first water tank 44 is connected to the first water conduit 410, when the height of the float ball does not reach the set value, the second float valve 46 is turned on, and the sewage enters the first water tank 44. Finally, the float ball of the second float valve 46 rises with the entrance height of the sewage. When the height of the float ball of the second float valve 46 reaches the set value, the second float valve 46 is closed, and the sewage is intercepted. During the sewage infusion process, when the height of the sewage is slightly higher than the outlet of the universal pipe 49, the sewage is discharged. When the height of the water outlet is high, due to the principle of communicating vessels, the sewage is discharged from the universal tube 49 connected to the lower surface of the first water tank 44. Due to gravity, the sewage flows into the second water tank 45, and then is discharged through the second water outlet 48 on the lower surface of the second water tank 45, flows to the flat water distributor 411, and then flows into the sewage filling tower 412 after the water volume is evenly distributed through the flat water distributor 411. Microorganisms will grow on the sewage filling tower 412 to form a microbial film. The microbial film absorbs organic pollutants in the sewage, and decomposes and utilizes the organic pollutants to facilitate the growth of the microbial film. After passing through the sewage filling tower 412, the sewage flows into the water collecting tank 413 below, and then the clean water in the water collecting tank 413 is discharged through the drainage pump 418. During this process, the sewage flows through the first water storage tank 44, the second water storage tank 45, the flat water distributor 411, the sewage packing tower 412 and the water collection tank 413, so that the time-varying effect of rural sewage is reduced to zero. No matter how much the instantaneous sewage volume is, it will definitely enter the filter tank shell 41 according to the set fixed flow rate, which maximizes the impact resistance of the filter tank. This equipment has no electrical equipment and truly achieves zero energy consumption. The types and quantities of this equipment are extremely small, and there is basically no problem of failure. It is safe and reliable. Once installed, this equipment does not require human control, and truly achieves unattended operation.

[0068] In the present technical solution, the septic unit, the coarse filtration unit and the tower biological filtration unit 24 can be constructed as a whole and installed in the same location, or they can be dispersedly arranged when there is insufficient space.

[0069] In this technical solution, the tower-type biological filtration unit is aerated by natural ventilation. The air inlet pipe 416 is on one side of the inner part of the outer shell 41 of the filter tank, extending downward to above the upper limit liquid level of the water collecting tank 413. The exhaust pipe 415 is installed on one side of the inner part of the filter tank shell 41, and the exhaust port of the exhaust pipe 415 extends from the side surface of the filter tank shell 41 to the outside of the filter tank shell 41 to enhance the exhaust effect.

[0070] In this technical solution, in order to prevent the drainage pump 418 from malfunctioning without anyone knowing, a fault alarm device is provided on the drainage pump 418. The alarm device is a pressure alarm device connected to the water outlet of the drainage pump 418, and the stable operation period of this device is more than 5 years. When the liquid level of the water collecting tank 413 of the tower biological filtration unit reaches the upper limit and the level gauge 43 of the water collecting tank 413 needs to start the drainage pump 418, the synchronous pressure alarm device starts to detect the pressure of the second water pipe 417. If the drainage pump 418 is operating normally, there is water pressure in the second water pipe 417, and the pressure alarm device does not alarm at this time. When the drainage pump 418 works abnormally, there is no pressure in the second water pipe 417, and the pressure alarm device starts to alarm.

[0071] In the present technical solution, a drainage pump 418 is also included. The drainage pump is a self-priming pump installed above the flat water distributor 411 of the sewage flow control unit. The second water pipe 417 and the liquid level meter 43 connected to the drainage pump 418 are both arranged in the air inlet pipe 416 and extend to the bottom of the water collecting tank 413. The start and stop of the drainage pump 418 are controlled by the liquid level meter 43 in the water collecting tank 413. A check valve is provided on one side of the second water pipe 417 connected to the drainage pump 418 to prevent the clean water in the second water pipe 417 connected to the drainage pump 418 from flowing back to the water collecting tank 413 at the bottom after the drainage pump 418 is shut down. If the clean water in the second water pipe 417 connected to the drainage pump 418 flows back to the water collecting tank 413 at the bottom, the drainage pump 418 needs to first discharge the air in the second water pipe 417 each time it starts to drain, resulting in a long drainage process.

[0072] Embodiment 2, as Figure 5 As shown:

[0073] A method for treating rural household sewage, the method comprising the following steps:

[0074] Step 1: Domestic sewage enters the septic tank and is separated and precipitated by gravity to form primary sewage;

[0075] Step 2: The primary sewage is coarsely filtered, and the intercepted solid matter is anaerobically digested and decomposed to form secondary sewage;

[0076] Step 3: Biochemical filtration of secondary sewage to attach pollutants to the surface of the filter material to form clear water:

[0077] Step 4: The liquid level in the clarification chamber is limited by the liquid level valve of the reflux device to maintain the water inflow of the tower biological filtration unit 24 .

[0078] Embodiment three, as Figure 6 As shown:

[0079] A construction method for a rural household sewage treatment device, the method comprising the following steps:

[0080] Step 1: Level the ground;

[0081] Step 2: Digging the land;

[0082] Step 3: Pre-bury the septic tank underground;

[0083] Step 4: The septic tank, the coarse filter unit and the biological filter are connected by pipes;

[0084] Step 5: The return end of the return unit extends into the clarification chamber of the septic tank.

[0085] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A rural household sewage treatment device, comprising a feces inlet pipe (1), characterized in that: It also includes a septic unit, a coarse filter unit and a tower-type biological filter unit, wherein the septic unit, the coarse filter unit and the tower-type biological filter unit are connected in sequence through pipelines, and the discharge port of the manure inlet pipe (1) is connected to the interior of the septic unit; The septic unit is used to preliminarily treat domestic sewage, degrade solids and sludge in the sewage into soluble substances, and decompose macromolecular organic matter into small molecular substances. The septic unit filters out primary sewage; The coarse filtration unit is used to filter the primary sewage, perform anaerobic digestion on the solid matter in the primary sewage, and filter out the secondary sewage; The tower biological filtration unit is used to filter the secondary sewage, attach pollutants and bacteria in the secondary sewage, filter out clean water from the tower biological filtration unit, and the clean water flows out of the tower biological filtration unit from the drainage system and is discharged into the outdoor sewer; The septic unit comprises a septic tank (3), a first partition (4), a second partition (5), a first folding tube (6), and a second folding tube (7), wherein: The septic tank (3) is pre-buried in a foundation pit, and a first partition (4) and a second partition (5) are provided inside the septic tank (3); The first partition (4) and the second partition (5) divide the inner cavity of the septic tank (3) into a primary anaerobic chamber (8), a secondary anaerobic chamber (9), and a clarification chamber (10) which are not connected to each other; A first folded tube (6) is provided in the first anaerobic chamber (8), and a water outlet end of the first folded tube (6) passes through the first partition plate (4) and enters the second anaerobic chamber (9); A second folded tube (7) is provided in the secondary anaerobic chamber (9), and a water outlet end of the second folded tube (7) passes through the second partition plate (5) and enters the clarification chamber (10); It also includes a reflux unit, which includes a three-way valve (19), a first water pipe (20), a second water pipe (21) and a reflux pipe (22), wherein: A pair of branch pipes of the three-way valve (19) are respectively connected to the first water pipe (20) and the second water pipe (21); The main pipe of the three-way valve (19) is connected to the return pipe (22); The first water pipe (20) is connected to a drainage pump in the tower-type biological filtration unit; The second water pipe (21) is connected to an outdoor sewer; The reflux pipe (22) extends into the clarification chamber (10); A first float valve (23) is provided at the water outlet of the return pipe (22); The tower-type biological filtration unit is installed under the ground surface. The sewage enters the first water tank of the sewage flow control unit inside the filter tank shell through the first water inlet, the first water conduit, and the second water inlet in sequence. Since the second float valve in the first water tank is connected to the first water conduit, when the height of the float does not reach the set value, the second float valve is turned on, and the sewage enters the first water tank. Finally, the float of the second float valve rises with the entry height of the sewage. When the height of the float of the second float valve reaches the set value, the second float valve is closed, and the sewage is intercepted. During the sewage injection process, due to the principle of the communicating vessel, the sewage is discharged from the universal pipe connected to the lower surface of the first water tank. Due to gravity, the sewage flows into the second water tank and then is guided through the second water outlet on the lower surface of the second water tank. Outflow, flow to the flat plate water distributor, the water is evenly distributed by the flat plate water distributor and then flows into the sewage packing tower. Microorganisms will grow on the sewage packing tower to form a microbial film, which absorbs organic pollutants in the sewage and decomposes and utilizes the organic pollutants, which is convenient for the growth of the microbial film. After passing through the sewage packing tower, the sewage flows into the water collection tank below, and then the clean water in the water collection tank is discharged through the drainage pump; in this process, the sewage flows through the first water storage tank, the second water storage tank, the flat plate water distributor, the sewage packing tower and the water collection tank, so that the time change effect of rural sewage is reduced to zero. No matter how much the instantaneous sewage volume is, it will definitely enter the filter tank shell of the tower filter unit according to the set fixed flow rate, which maximizes the impact resistance of the filter tank of the tower filter unit. The start and stop of the drainage pump is controlled by the liquid level gauge in the water collecting tank.

2. A rural household sewage treatment device according to claim 1, characterized in that: An exhaust port (11) is formed on the upper surface of the septic tank (3), and the exhaust port (11) is connected to the primary anaerobic chamber (8).

3. A rural household sewage treatment device according to claim 1 or 2, characterized in that: A slag discharge port (12) is formed on the upper surface of the septic tank (3), and the slag discharge port (12) is connected to the primary anaerobic chamber (8). An observation port (13) is formed on the upper surface of the septic tank (3), and the observation port (13) is connected to the clarification chamber (10).

4. A rural household sewage treatment device according to claim 1 or 2, characterized in that: The plane where the water inlet of the first folded tube (6) is located is lower than the plane where the water inlet of the second folded tube (7) is located.

5. A rural household sewage treatment device according to claim 1, characterized in that: The coarse filter unit comprises a coarse filter housing (14), a water inlet (15), a water outlet (16), an upper filter material layer (17), and a lower filter material layer (18), wherein the water inlet (15) is formed on a first surface of the coarse filter housing (14), the water outlet (16) is formed on a second surface of the coarse filter housing (14), and the upper filter material layer (17) and the lower filter material layer (18) are provided inside the coarse filter housing (14).

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