Sewage deep nitrogen and phosphorus removal treatment device

Abstract

The utility model relates to the technical field of water treatment, in particular to a sewage deep nitrogen and phosphorus removal treatment device which comprises a first reaction tank, a second reaction tank, a sedimentation tank and a third reaction tank which are connected in sequence, the first reaction tank is used for carrying out denitrification treatment on the sewage, so that nitrate in the sewage is reduced into nitrogen, and the total nitrogen concentration of the sewage is reduced; the second reaction tank is used for carrying out aerobic treatment on the sewage, so that ammonia in the sewage is oxidized into nitric acid, and phosphorus, organic matters and chemical oxygen demand in the sewage are reduced; the third reaction tank is used for carrying out denitrification treatment on the sewage. The sewage treatment device has the beneficial effects that denitrification and aerobic reaction processes are optimized according to the quality of sewage, the denitrification reaction time is prolonged through the first reaction tank, organic matters in inlet water are fully utilized for denitrification nitrogen removal, and meanwhile, chemical oxygen demand and total nitrogen are removed. The second reaction tank is used for completing nitration reaction and further reducing the chemical oxygen demand of the sewage.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to a sewage deep denitrification and dephosphorization treatment device. Background Art

[0002] Rural domestic sewage includes kitchen wastewater, shower and washing wastewater, toilet flushing wastewater, and free-range livestock and poultry manure according to the source. There are problems such as large amount of sewage, mixed rainwater and sewage, imperfect collection pipe network, low treatment efficiency, and lack of professional operation and maintenance in rural domestic sewage in my country. In 2022, the collection and treatment rate of rural domestic sewage was only 31%. At present, rural domestic sewage is mainly treated in a simple way, including septic tanks, ecological ponds, artificial wetlands, land treatment, and sewage irrigation. The pollutant removal efficiency is low and the seasonal impact is significant. A large amount of pollutants, nutrients, and toxic and harmful microorganisms in sewage are discharged into the rural water environment, causing pollution to rivers, lakes, reservoirs, and groundwater, endangering rural water ecology and rural drinking water safety. Therefore, there is a need for a rural domestic sewage treatment device with high treatment efficiency, low power agent consumption, simple operation and maintenance management, and stable low-temperature treatment effect. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a sewage deep denitrification and dephosphorization treatment device.

[0004] The utility model is realized through the following technical solutions:

[0005] A sewage deep denitrification and dephosphorization treatment device, comprising a first reaction tank, a second reaction tank, a sedimentation tank and a third reaction tank connected in sequence;

[0006] The first reaction tank is used to perform denitrification treatment on the sewage to reduce the nitrate in the sewage to nitrogen gas and reduce the total nitrogen concentration of the sewage;

[0007] The second reaction tank is used to aerobically treat the sewage to oxidize ammonia in the sewage into nitric acid and reduce phosphorus, organic matter and chemical oxygen demand in the sewage;

[0008] The sludge in the sewage can be precipitated in the sedimentation tank;

[0009] The third reaction tank is used to perform denitrification treatment on the sewage to reduce nitrogen and phosphorus in the sewage.

[0010] Preferably, the sewage deep denitrification and phosphorus removal treatment device also includes a storage tank, and the storage tank is used to store sewage.

[0011] Preferably, the sewage deep denitrification and dephosphorization treatment device further comprises a regulating tank and a first driving member;

[0012] The storage tank is connected to the regulating tank so that the sewage in the storage tank can enter the regulating tank;

[0013] The inlet of the first driving member is connected to the interior of the regulating tank, and the outlet of the first driving member is connected to the first reaction tank. The first driving member can drive the sewage in the regulating tank to enter the first reaction tank.

[0014] Preferably, a first filler is disposed in the middle of the first reaction tank, and denitrifying microorganisms in the sewage can adhere to the first filler; and / or

[0015] A stirrer is provided at the bottom of the first reaction tank, and the stirrer can stir the sewage at the bottom of the first reaction tank to improve the reaction mass transfer in the first reaction tank.

[0016] Preferably, a second filler is disposed in the middle of the second reaction tank, and aerobic microorganisms in the sewage can adhere to the second filler; and / or

[0017] The sewage deep denitrification and phosphorus removal treatment device also includes a second driving member, the inlet of the second driving member is connected to the second reaction tank, the outlet of the second driving member is connected to the first reaction tank, and the second driving member can drive the digestion liquid in the second reaction tank to flow to the first reaction tank.

[0018] Preferably, a sloping plate filler is provided in the middle of the sedimentation tank; and / or

[0019] The sewage deep denitrification and phosphorus removal treatment device also includes a third driving member, the inlet of the third driving member is connected to the sedimentation tank, the outlet of the second driving member is connected to the first reaction tank, and the second driving member can drive the sludge in the sedimentation tank to flow to the first reaction tank.

[0020] Preferably, the sewage deep denitrification and phosphorus removal treatment device also includes a sludge tank and a fourth driving member, the inlet of the fourth driving member is connected to the sedimentation tank, the outlet of the fourth driving member is connected to the sludge tank, and the fourth driving member can drive the sludge in the sedimentation tank to flow into the sludge tank.

[0021] Preferably, the sewage deep denitrification and phosphorus removal treatment device also includes a fifth driving member, the inlet of the fifth driving member is connected to the sludge tank, the outlet of the fifth driving member is connected to the storage tank, and the fifth driving member can drive the sludge in the sedimentation tank to flow into the storage tank.

[0022] Preferably, the sewage deep denitrification and dephosphorization treatment device further comprises a sewage circulation heating component, and the sewage circulation heating component comprises a sixth driving element, a first filtering element and a heating element which are cyclically connected in sequence;

[0023] The sixth driving member is disposed in the third reaction tank, and the sixth driving member can drive the water in the third reaction tank to flow back to the third reaction tank after passing through the first filter element and the heating element;

[0024] The filter element can filter impurities in the water, and the heater element can heat the water.

[0025] Preferably, the sewage circulation heating component also includes a control element, a first end of the control element is connected to the outlet of the filter element, a second end of the control element is connected to the inlet of the heating element, and a third end of the control element is connected to the third reaction tank, and the control element can control the first end to selectively connect to the second end and the third end.

[0026] The beneficial effects of the utility model are:

[0027] According to the sewage quality, the denitrification and aerobic reaction processes are optimized, the denitrification reaction time is increased through the first reaction tank, and the organic matter in the influent is fully utilized for denitrification and nitrogen removal, while removing chemical oxygen demand and total nitrogen. The second reaction tank focuses on completing the nitrification reaction and further reducing the chemical oxygen demand of the sewage.

[0028] The third reaction tank further reduces total nitrogen through the sulfur autotrophic denitrification process. At the same time, zero-valent iron is added to the sulfur autotrophic denitrification filler to remove total phosphorus in the water through the iron salt produced during the reaction process, avoiding the need to set up a separate phosphorus removal and dosing system.

[0029] Heating the water temperature of the third reaction tank prioritizes the microbial activity of denitrifying bacteria in the third reaction tank under the low temperature environment in winter, optimizes the system operation effect, and improves the final effluent water quality compliance rate under the low temperature environment in winter.

[0030] The inclined plate filler is used to increase the surface hydraulic load of the sedimentation tank and optimize the sludge sedimentation effect. At the same time, a perforated aeration pipe is set under the inclined plate filler layer to effectively control the adhesion and clogging of the activated sludge on the filler. The remaining sludge is finally discharged to the storage tank at the front end of the device, which reduces the labor input for the cleaning of the remaining sludge of this device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a sewage deep denitrification and dephosphorization treatment device of the utility model.

[0032] Figure 2 It is a structural schematic diagram of a regulating tank of a sewage deep denitrification and dephosphorization treatment device of the utility model.

[0033] Figure 3 It is a structural schematic diagram of the first reaction tank of the sewage deep denitrification and dephosphorization treatment device of the utility model.

[0034] Figure 4 It is a structural schematic diagram of the second reaction tank of the sewage deep denitrification and dephosphorization treatment device of the utility model.

[0035] Figure 5 It is a structural schematic diagram of a sedimentation tank of a sewage deep denitrification and dephosphorization treatment device of the utility model.

[0036] Figure 6 It is a structural schematic diagram of a sludge tank of a sewage deep denitrification and dephosphorization treatment device of the utility model.

[0037] Figure 7 It is a structural schematic diagram of the third reaction tank of the sewage deep denitrification and dephosphorization treatment device of the utility model.

[0038] Figure 8 It is a structural schematic diagram of a clear water tank of a sewage deep denitrification and dephosphorization treatment device of the utility model.

[0039] In the figure: 1, storage tank; 2, regulating tank; 3, first reaction tank; 4, second reaction tank; 5, sedimentation tank; 6, third reaction tank; 7, sludge tank; 8, clean water tank; 9, aerator; 10, second filter element; 11, first drive element; 12, first liquid level detection element; 13, first aeration element; 14, upper grid plate; 15, first lower grid plate; 16, first filler; 17, agitator; 18, second filler; 19, second aeration element; 20, second drive element; 21, inclined plate filler material; 22, the third aeration element; 23, the third driving element; 24, the fourth driving element; 25, the fifth driving element; 26, the second liquid level detection element; 27, the second lower grid plate; 28, the baffle plate; 29, the third filler; 30, the sixth driving element; 31, the first filter element; 32, the heating element; 33, the first control valve; 34, the second control valve; 35, the first temperature detection element; 36, the second temperature detection element; 37, the check valve; 38, the seventh driving element; 39, the third liquid level detection element. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings and the best embodiment. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the utility model.

[0041] In the description of the utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the utility model.

[0042] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Reference Figure 1 The utility model provides a sewage deep denitrification and phosphorus removal treatment device, which includes a storage tank 1, a regulating tank 2, a first reaction tank 3, a second reaction tank 4, a sedimentation tank 5, a third reaction tank 6, a sewage circulation heating component, a sludge tank 7, a clear water tank 8 and an aerator 9.

[0044] The storage tank 1 is specifically a septic tank, preferably a three-chamber septic tank. Feces and sewage first enter the first compartment of the three-chamber septic tank, and the upper sewage can flow into the second and third compartments to precipitate impurities in the sewage.

[0045] Reference Figure 2 , the regulating tank 2 is connected to the storage tank 1. Specifically, the upper part of the third compartment of the three-compartment septic tank is connected to the inlet of the upper part of the regulating tank 2 through a pipeline, so that the sewage enters the regulating tank 2. Further, a second filter element 10 is provided at the inlet of the regulating tank 2, and the second filter element 10 is preferably a basket grille. The second filter element 10 can filter impurities in the sewage.

[0046] The regulating tank 2 is connected to the first reaction tank 3. Specifically, the bottom of the regulating tank 2 is connected to the inlet of the first driving member 11, and the outlet of the first driving member 11 is connected to the first reaction tank 3. The first driving member 11 is preferably a lifting pump, and the first driving member 11 can drive the sewage in the regulating tank 2 into the first reaction tank 3. Further, a first liquid level detection member 12 is provided in the regulating tank 2, and the first liquid level detection member 12 can detect the liquid level height of the sewage in the regulating tank 2. The first liquid level detection member 12 and the first driving member 11 are both connected to the controller by signal, and the controller can control the first driving member 11 according to the liquid level height detected by the first liquid level detection member 12. Specifically, when the liquid level in the regulating tank 2 is higher than the preset height, the first driving member 11 is started to make the sewage in the regulating tank 2 flow into the first reaction tank 3. And the amount of sewage entering the first reaction tank 3 from the regulating tank 2 each time does not exceed 20% of the volume of the first reaction tank 3. This arrangement enables the sewage to enter the first reaction tank 3 in batches, so that the sewage has sufficient space in the first reaction tank 3 for treatment.

[0047] Furthermore, a first aeration member 13 is provided at the bottom of the regulating tank 2, and the first aeration member 13 is specifically a rubber tube aerator. The first aeration member 13 is connected to the aerator 9 through a pipeline. The aerator 9 can drive the external air to be discharged into the bottom of the regulating tank 2 through the first aeration member 13, and the rubber tube aerator is used to prevent impurities in the sewage from being deposited at the bottom of the regulating tank 2.

[0048] Reference Figure 3 , an upper grid plate 14 and a first lower grid plate 15 are arranged in the first reaction tank 3, and a first filler 16 is arranged between the upper grid plate 14 and the first lower grid plate 15. The shell of the first filler 16 is a hollow spherical structure, made of polypropylene material, and filled with polyurethane sponge, with a filling ratio of 50%. Sewage can flow into the first filler 16, and the denitrifying microorganisms in the sewage can adhere to the polyurethane sponge, and the denitrifying microorganisms can denitrify the sewage. Specifically, the denitrifying microorganisms can reduce the nitrate in the sewage to nitrogen gas to reduce the total nitrogen concentration of the sewage, and can also reduce the chemical oxygen demand of the second reaction tank 4. In addition, the denitrifying microorganisms can degrade the nitrogen-containing organic matter in the sewage into ammonia, thereby increasing the alkalinity of the sewage. Further, a gap is provided between the lower grid plate and the bottom of the first reaction tank 3, and an agitator 17 is provided in the gap, specifically a submersible agitator 17. The agitator 17 can stir the sewage at the bottom of the first reaction tank 3 so that the sewage is fully contacted with the denitrifying microorganisms in the first filler 16 for denitrification.

[0049] Reference Figure 4, a second filler 18 is provided in the second reaction tank 4. The second filler 18 is specifically an elastic fiber bundle, and the filling ratio is 60%. Aerobic microorganisms in the sewage can adhere to the second filler 18. The sewage and the aerobic microorganisms undergo aerobic reactions, and the ammonia in the sewage can be oxidized into nitric acid. Aerobic microorganisms can also absorb phosphorus in the sewage and oxidize organic matter in the sewage to reduce the chemical oxygen demand of the sewage. The first reaction tank 3 is connected to the second reaction tank 4. Specifically, the space above the upper grid plate 14 of the first reaction tank 3 is connected to one end of the first connecting pipe, and the other end of the first connecting pipe is connected to the space above the second filler 18 in the second reaction tank 4. The clear liquid in the upper part of the first reaction tank 3 can flow into the second reaction tank 4 through the first connecting pipe. A second aeration member 19 is provided at the bottom of the second reaction tank 4, and the second aeration member 19 is specifically a microporous aeration disk. The second aeration member 19 is connected to the aerator 9 through a pipeline. The aerator 9 can drive external air to be discharged into the bottom of the second reaction tank 4 through the second aeration member 19 to prevent impurities in the sewage from being deposited at the bottom of the second reaction tank 4. A second driving member 20 is provided in the second reaction tank 4, and the second driving member 20 is specifically a reflux pump, the inlet of which is connected to the bottom of the second reaction tank 4, and the outlet of which is connected to the middle and lower part of the first filler 16 of the first reaction tank 3. The second driving member 20 can drive the nitrification liquid at the bottom of the second reaction tank 4 to flow back into the first reaction tank 3.

[0050] Reference Figure 5 , an inclined plate filler 21 is arranged in the middle of the sedimentation tank 5. The second reaction tank 4 is connected to the sedimentation tank 5. Specifically, the space above the second filler 18 of the second reaction tank 4 is connected to one end of the second connecting pipe, and the other end is connected to the bottom of the inclined plate filler 21 of the sedimentation tank 5. When sewage passes through the inclined plate filler 21, large impurities will be formed. A third aeration member 22 is also arranged in the sedimentation tank 5, and the third aeration member 22 is connected to the aerator 9 through a pipeline. The aerator 9 can drive the external air to be discharged into the sedimentation tank 5 through the third aeration member 22, so that the impurities attached to the inclined plate filler 21 fall off. A third driving member 23 is arranged in the sedimentation tank 5, and the third driving member 23 is specifically a reflux pump. The inlet of the third driving member 23 is connected to the bottom of the sedimentation tank 5, and the outlet thereof is connected to the first reaction tank 3. The third driving member 23 can drive the sludge at the bottom of the sedimentation tank 5 into the first reaction tank 3. A fourth driving member 24 is also arranged in the sedimentation tank 5, and the fourth driving member 24 is specifically a sludge pump. The inlet of the fourth driving member 24 is connected to the bottom of the sedimentation tank 5, and the outlet thereof is connected to the sludge tank 7. The fourth driving member 24 can drive the sludge at the bottom of the sedimentation tank 5 to flow into the sludge tank 7.

[0051] Reference Figure 6, a fifth driving member 25 is provided in the sludge tank 7, and the fifth driving member 25 is specifically a sludge pump. The inlet of the fifth driving member 25 is connected to the sludge tank 7, and the outlet thereof is connected to the storage tank 1. Specifically, it is connected to the first compartment of the three-compartment septic tank. The fifth driving member 25 can drive the sludge in the sludge tank 7 to flow into the storage tank 1. A second liquid level detection member 26 is also provided in the sludge tank 7, and the second liquid level detection member 26 can detect the liquid level of the sludge tank 7. When the liquid level is higher than the preset liquid level, the fifth driving member 25 is started to drive the sludge to flow into the storage tank 1.

[0052] Reference Figure 7 , a second lower grid plate 27 is provided at the bottom of the third reaction tank 6, and a baffle plate 28 is also provided in the third reaction tank 6. The baffle plate 28 is vertically arranged, and its bottom is connected to the second lower grid plate 27. The baffle plate 28 divides the space above the second lower grid plate 27 into a large cavity with a larger space and a small cavity with a smaller space. A third filler 29 is provided in the large cavity, and the specific components of the third filler 29 include diatomaceous earth, limestone, sulfur and zero-valent iron, and a granular filler with a diameter of 3-5 cm is formed by a granulator. Sulfur autotrophic denitrifying microorganisms in sewage can attach to the third filler 29, and sulfur autotrophic denitrifying microorganisms can reduce nitrogen and phosphorus in sewage. The zero-valent iron in the third filler 29 can produce iron salts during the reaction to remove phosphorus in the water, so there is no need to set up a separate dephosphorization device. The sedimentation tank 5 is connected to the third reaction tank 6. Specifically, the space above the inclined plate filler 21 in the sedimentation tank 5 is connected to one end of the third connecting pipe, and the other end is connected to the space above the third filler 29 in the third reaction tank 6. The clear liquid in the upper layer of the sedimentation tank 5 can flow into the third reaction tank 6 through the third connecting pipe. A gap is provided between the lower grid plate and the bottom surface of the third reaction tank 6. The bottom of the large cavity provided with the third filler 29 is connected to the gap through the lower grid plate, and the gap is also connected to the small cavity. After the sewage is fully in contact with the third filler 29 in the large cavity, it flows into the small cavity through the gap at the bottom.

[0053] Continue to refer to Figure 7, the sewage circulation heating component can heat the sewage by using solar energy in the low temperature environment in winter, increase the operating temperature of the third reaction tank, and ensure the reaction activity of sulfur autotrophic denitrifying microorganisms. The sewage circulation heating component includes a sixth driving member 30, a first filter 31 and a heating member 32. The inlet of the sixth driving member 30 is connected to the gap at the bottom of the third reaction tank 6, and its outlet is connected to the inlet of the first filter 31. The outlet of the first filter 31 is connected to the inlet of the heating member 32, and the outlet of the heating member 32 is connected to the cavity above the third filler 29 in the third reaction tank 6. The sixth driving member 30 is specifically a water pump, and the sixth driving member 30 can drive the sewage at the bottom of the third reaction tank 6 to pass through the first filter 31 and the heating member 32, and then flow back to the top of the third reaction tank 6. The first filter 31 can filter impurities in the sewage, prevent impurities from entering the heating member 32, and backflow into the third reaction tank 6. Specifically, the first filter 31 is a self-cleaning filter, and during self-cleaning, the impurities in the first filter 31 can be discharged into the sedimentation tank 5. The heating element 32 is specifically a solar water heater, which can heat the sewage and return the high-temperature water to the third reaction tank 6. The sewage circulation heating component can increase the water temperature in the third reaction tank 6, thereby strengthening the reaction mass transfer and improving the reaction activity of the autotrophic denitrification microorganisms.

[0054] Further, the sewage circulation heating component also includes a control member, which is specifically a three-way pipe, the first end of which is connected to the outlet of the first filter element 31, the second end is connected to the inlet of the heater, and the third end is connected to the third reaction tank 6. A first control valve 33 is provided on the second end of the three-way pipe, and the first control valve 33 can adjust the opening to open or close the second end. A second control valve 34 is provided on the third end of the three-way pipe, and the second control valve 34 can adjust the opening to open or close the third end. The connection mode of the control member can be controlled by the first control valve 33 and the second control valve 34. A check valve 37 is provided at the outlet of the heating element 32 to prevent water from flowing back into the heating element 32. Further, a first temperature detection member 35 is provided in the third reaction tank 6, and the first temperature detection member 35 can detect the water temperature of the third reaction tank 6. A second temperature detection member 36 is provided in the heating element 32. The second temperature detection member 36 can detect the water temperature of the heating element 32.

[0055] The control method of the sewage circulation heating component is: controlling the opening and closing state of the sixth driving member 30 and the connection mode of the control member according to the water temperature of the third reaction tank 6. Specifically, it includes the following two situations:

[0056] 1) When the water temperature of the third reaction tank 6 reaches the preset temperature, the sixth driving member 30 is started, the first control valve 33 is closed, and the second control valve 34 is opened. The sixth driving member 30 drives the sewage at the bottom of the third reaction tank 6 to enter the first filter element 31, and the filtered sewage flows into the upper part of the third reaction tank 6 through the third end of the control member to strengthen the reaction mass transfer of the third reaction tank 6.

[0057] 2) When the water temperature of the third reaction tank 6 does not reach the preset temperature, and the water temperature of the heating element 32 is higher than the water temperature of the third reaction tank 6, the sixth driving element 30 is started, the first control valve 33 is opened, and the second control valve 34 is closed. The sixth driving element 30 drives the sewage at the bottom of the third reaction tank 6 to enter the first filter element 31, and after being filtered by the first filter element 31, it flows into the heating element 32, and after being heated by the heating element 32, it flows into the third reaction tank 6 to increase the water temperature of the third reaction tank 6.

[0058] Reference Figure 8 , the clean water tank 8 is connected to the third reaction tank 6. Specifically, the upper part of the small cavity of the third reaction tank 6 is connected to one end of the fourth connecting pipe, and the other end is opened to connect to the clean water tank 8. The treated water in the small cavity flows into the clean water tank 8. A seventh driving component 38 is provided in the clean water tank 8, and the seventh driving component 38 is specifically a water outlet pump. The inlet of the seventh driving component 38 is connected to the inside of the clean water tank 8, and the outlet thereof is connected to the outside of the clean water tank 8. The seventh driving component 38 can discharge the water in the clean water tank 8. Specifically, the water in the clean water tank 8 can be used to irrigate the canal. The clean water tank 8 is also provided with a third liquid level detection component 39. The third liquid level detection component 39 can detect the liquid level in the clean water tank 8. When the liquid level in the clean water tank 8 reaches the preset liquid level, the seventh driving component 38 is started to discharge the water in the clean water tank 8.

[0059] The working principle of the sewage deep denitrification and dephosphorization treatment device is as follows: when the device is running, the aerator 9, the stirrer 17 in the first reaction tank 3, the second driving member 20 in the second reaction tank 4, and the third driving member 23 in the sedimentation tank 5 are turned on and run continuously. The first driving member 11 in the regulating tank 2 is started according to the liquid level in the regulating tank 2, driving the sewage in the regulating tank 2 to flow into the first reaction tank 3. Furthermore, the first aeration member 13 in the regulating tank 2 is opened and closed synchronously with the first driving member 11, so that the sediment at the bottom of the regulating tank 2 can flow into the first reaction tank 3.

[0060] At the same time, the second driving member 20 drives the nitrification liquid in the second reaction tank 4 into the first reaction tank 3, and the third driving member 23 drives the sludge at the bottom of the sedimentation tank 5 into the first reaction tank 3. The sewage, nitrification liquid and sludge are mixed in the first reaction tank 3 for denitrification treatment. The agitator 17 in the first reaction tank 3 stirs to fully mix the sewage, nitrification liquid and sludge to strengthen the mass transfer between the biofilm and the pollutants. The first reaction tank 3 can reduce the total nitrogen concentration in the sewage, reduce the chemical oxygen demand load of the second reaction tank 4, and provide alkalinity for the nitrification reaction of the second reaction tank 4.

[0061] The denitrified sewage flows into the second reaction tank 4, and the second aeration element 19 inputs external air into the second reaction tank 4 to maintain the dissolved oxygen concentration in the tank. The sewage undergoes aerobic nitrification in the second reaction tank 4 to oxidize ammonia and remove phosphorus and organic matter in the sewage.

[0062] The sewage after aerobic nitrification treatment enters the lower part of the inclined plate filler 21 of the sedimentation tank 5, and aggregates are formed when the sewage passes through the inclined plate filler 21. The third aeration element 22 supplies air to the inclined plate filler 21, so that impurities attached to the inclined plate filler 21 fall off and settle to the bottom of the sedimentation tank 5.

[0063] The sewage flows into the third reaction tank 6 through the inclined plate filler 21. The sewage is subjected to sulfur autotrophic denitrification treatment in the third reaction tank 6. The sulfur autotrophic process overcomes the disadvantages of deep denitrification processes such as traditional denitrification filters, such as large carbon source consumption, high sludge yield, and COD penetration. At the same time, in order to achieve the effect of synchronous phosphorus removal, zero-valent iron is added to the denitrification filler. In addition, the sewage circulation heating component can increase the water temperature of the third reaction tank 6 to strengthen the reaction mass transfer and enhance the reaction activity of autotrophic denitrification microorganisms.

[0064] When the amount of sludge in the sedimentation tank 5 is large, the fourth driving member 24 is started to drive the sludge in the sedimentation tank 5 into the sludge tank 7. The sludge tank 7 controls the fifth driving member 25 according to the liquid level to drive the sludge in the sludge tank 7 into the storage tank 1. This arrangement replaces the traditional regular suction method of the sludge suction truck to remove the sludge, and instead discharges it to the first of the three septic tanks at the front end of the device. This sludge treatment method is adopted in view of the insufficient volume of the sludge tank 7 and the high frequency and cost of cleaning and transportation by the sludge suction truck. The septic tank has a large capacity, and a long stay in the septic tank can decompose the remaining sludge, which reduces the amount of solid waste to be transported on the one hand, and the decomposition products of the remaining sludge can increase the carbon-nitrogen ratio of the water inlet of the device on the other hand.

[0065] Two embodiments are provided below:

[0066] Embodiment 1:

[0067] Referring to Table 1, the operation mode of this embodiment is the summer mode (April-October each year), and the water volume fluctuation range during operation is 23.7-47.3t / d (drainage pump outlet flow meter data). During the rainy season, part of the rainwater will flow into the sewage pipe through the inspection manhole cover, the water collection in the farmer's yard, etc., resulting in an instantaneous surge in water volume. This embodiment eliminates the surge in water volume and the impact on water quality caused by the mixing of rainwater. The water temperature change (sampling and testing in the regulating tank 2) ranges from 16.8 to 25.6°C. The inlet water quality analysis is carried out by selecting one day each in the early, middle and late part of each month during the operation period, and taking the average of the water quality of three samples taken in the morning, noon and evening of the same day; the outlet water quality analysis is tested on the day after the inlet sampling, and the mixed water sample of the three water samples taken in the morning, noon and evening is tested during the operation cycle.

[0068] When operating in summer mode, the actual operating time is 16 hours per day (including shutdowns during the operating cycle). The HRT of each section of the system is reviewed based on the actual operating time of the equipment and the maximum water inflow during operation: 28.46 hours for the regulating tank, 4.23 hours for the first reaction tank, 4.23 hours for the second reaction tank, 5.64 hours for the third reaction tank, and 81.35 hours for the clear water tank. The surface hydraulic load of sedimentation tank 5 is 0.94m3 / (m2h).

[0069] The experimental results show that the first reaction tank uses the organic matter in the influent to denitrify the reflux nitrification liquid, and the removal rates of chemical oxygen demand COD and total nitrogen TN reach 58.34% and 53.17% respectively; some nitrogen-containing organic matter in the influent is degraded into ammonia nitrogen in the first reaction tank, resulting in ammonia nitrogen concentration in this section increasing by 13.18% compared with the influent; water quality testing shows that the denitrification section has a total phosphorus TP removal rate of only 10.44%, and the removal in this section is mainly due to the adsorption of microorganisms.

[0070] Aerobic microorganisms in the second reaction tank further degrade the chemical oxygen demand COD, and the COD concentration of the effluent in this section is reduced to 21.6 mg / L, and the degradable organic matter in the sewage is basically removed; the nitrification reaction activity in the second reaction tank is good, and the ammonia nitrogen removal rate reaches 110.4% (including the increased ammonia nitrogen in the first reaction tank); this device does not have an anaerobic tank, and the aerobic phosphorus removal efficiency of microorganisms is not high, and the total phosphorus TP removal rate in the second reaction tank is 36.36%.

[0071] The autotrophic denitrification process in the third reaction tank played a considerable role, with the total nitrogen (TN) removal rate reaching 23.76% and the effluent total nitrogen (TN) concentration reduced to 1.78 mg / L; at the same time, the zero-valent iron in the filler participated in the microbial reaction process, and the generated iron salts reacted with phosphates in the water to form insoluble iron phosphates, which were removed from the water body, and the effluent total phosphorus (TP) concentration was 0.15 mg / L.

[0072] In summary, the concentrations of chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TN) and total phosphorus (TP) in the device inlet water were 224.6 mg / L, 22.46 mg / L, 47.85 mg / L and 2.97 mg / L respectively, and the total removal rates of the above pollutants were 92.3%, 98.93%, 96.28% and 95.12% respectively. The final pollutant concentrations in the effluent were 17.3 mg / L, 0.24 mg / L, 1.78 mg / L and 0.15 mg / L respectively. The main pollutant indicators in the effluent met the Level A standard in the Pollutant Discharge Standard for Urban Sewage Treatment Plants GB18918-2002, among which the chemical oxygen demand (COD), ammonia nitrogen and total phosphorus (TP) indicators met the Class III water quality standard in the Environmental Quality Standard for Surface Water GB3838-2002.

[0073] Table 1 Average concentration and removal rate of pollutants in each process section of the device under summer mode

[0074]

[0075] Note: The removal rate calculation of each section takes into account the reflux dilution effect. The removal rate is the ratio of the actual removal amount of each section to the pollutant concentration in the influent.

[0076] Embodiment 2:

[0077] Referring to Table 2, the operation mode of this embodiment is winter mode (November to March of the following year). The water volume during winter is lower than that in summer, with a fluctuation range of 19.6 to 31.2 t / d. The water temperature varies from 8.9 to 17.4°C. The sampling and testing standards for inlet / outlet water quality analysis are consistent with those in the summer mode. By comparing the water quality, water volume and water temperature in the summer mode of Example 1, it can be found that the drainage volume in winter is small, mainly due to the small amount of gray water discharged from showers and washrooms, which also leads to an increase in the proportion of black water in sewage, a higher concentration of pollutants in sewage, and a water temperature that is 8°C lower than the average water temperature in summer.

[0078] When operating in winter mode, the actual operating time is 12 hours per day (including shutdowns during the operating cycle). The HRT of each section of the system is reviewed based on the actual operating time of the equipment and the maximum water inflow during operation: 29.62 hours for the regulating tank, 4.81 hours for the first reaction tank, 4.81 hours for the second reaction tank, 6.41 hours for the third reaction tank, and 81.54 hours for the clear water tank. The surface hydraulic load of sedimentation tank 5 is 0.82m3 / (m2h).

[0079] The experimental results show that the overall trend of the first, second and third reaction pools in removing pollutants is similar to that in summer, but the removal effect of each pollutant is somewhat lower than that in summer, and the drop in inlet water temperature inhibits the microbial reaction activity in the system. After turning on the circulating heating system, the water temperature in the third reaction pool is 5-8℃ higher than the inlet water temperature, and the average water temperature in the pool is ≥17℃.

[0080] By comparing the results of the two embodiments, it can be seen that since the first reaction tank and the second reaction tank adopt the biofilm process, the system's adaptability to changes in ambient temperature is improved, and the impact of the low temperature environment on the biological activity of microorganisms is reduced to an acceptable range. The final effluent indicators can still meet the Level A standard in the "Pollutant Discharge Standard for Urban Wastewater Treatment Plants" GB18918-2002.

[0081] At the same time, the water temperature of the third reaction tank is increased by the solar circulation heating system, so that the reaction activity of autotrophic denitrifying bacteria, which are more sensitive to ambient temperature, is guaranteed, which plays a key role in achieving the standard total nitrogen TN and total phosphorus TP concentrations in the final effluent.

[0082] During the operation of the equipment in the above two embodiments, except for the on-site inlet and outlet water sampling requirements, the equipment is remotely operated by a mobile phone APP throughout the entire process, and no on-site manual operations occur, which greatly reduces the workload and reduces the equipment operation and maintenance costs.

[0083] Table 2 Average concentration and removal rate of pollutants in each process section of the device under winter mode

[0084]

[0085] Note: The removal rate calculation of each section takes into account the reflux dilution effect. The removal rate is the ratio of the actual removal amount of each section to the pollutant concentration in the influent.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A sewage deep denitrification and phosphorus removal treatment device, characterized in that: It includes a first reaction tank, a second reaction tank, a sedimentation tank and a third reaction tank connected in sequence; The first reaction tank is used to perform denitrification treatment on the sewage to reduce the nitrate in the sewage to nitrogen gas and reduce the total nitrogen concentration of the sewage; The second reaction tank is used to aerobically treat the sewage to oxidize ammonia in the sewage into nitric acid and reduce phosphorus, organic matter and chemical oxygen demand in the sewage; The sludge in the sewage can be precipitated in the sedimentation tank; The third reaction tank is used to perform denitrification treatment on the sewage to reduce nitrogen and phosphorus in the sewage.

2. A sewage deep denitrification and dephosphorization treatment device according to claim 1, characterized in that: The sewage deep denitrification and dephosphorization treatment device also includes a storage tank, which is used to store sewage.

3. A sewage deep denitrification and dephosphorization treatment device according to claim 2, characterized in that: The sewage deep denitrification and dephosphorization treatment device also includes a regulating tank and a first driving member; The storage tank is connected to the regulating tank so that the sewage in the storage tank can enter the regulating tank; The inlet of the first driving member is connected to the interior of the regulating tank, and the outlet of the first driving member is connected to the first reaction tank. The first driving member can drive the sewage in the regulating tank to enter the first reaction tank.

4. A sewage deep denitrification and dephosphorization treatment device according to claim 1, characterized in that: A first filler is disposed in the middle of the first reaction tank, and denitrifying microorganisms in the sewage can adhere to the first filler; and / or A stirrer is provided at the bottom of the first reaction tank, and the stirrer can stir the sewage at the bottom of the first reaction tank to improve the reaction mass transfer in the first reaction tank.

5. The sewage deep denitrification and dephosphorization treatment device according to claim 1 is characterized in that: A second filler is disposed in the middle of the second reaction tank, and aerobic microorganisms in the sewage can adhere to the second filler; and / or The sewage deep denitrification and phosphorus removal treatment device also includes a second driving member, the inlet of the second driving member is connected to the second reaction tank, the outlet of the second driving member is connected to the first reaction tank, and the second driving member can drive the digestion liquid in the second reaction tank to flow to the first reaction tank.

6. A sewage deep denitrification and dephosphorization treatment device according to claim 1, characterized in that: A sloping plate filler is arranged in the middle of the sedimentation tank; and / or The sewage deep denitrification and phosphorus removal treatment device also includes a third driving component, the inlet of the third driving component is connected to the sedimentation tank, the outlet of the third driving component is connected to the first reaction tank, and the third driving component can drive the sludge in the sedimentation tank to flow to the first reaction tank.

7. A sewage deep denitrification and dephosphorization treatment device according to claim 2, characterized in that: The sewage deep denitrification and phosphorus removal treatment device also includes a sludge tank and a fourth driving member, the inlet of the fourth driving member is connected to the sedimentation tank, the outlet of the fourth driving member is connected to the sludge tank, and the fourth driving member can drive the sludge in the sedimentation tank to flow into the sludge tank.

8. The sewage deep denitrification and dephosphorization treatment device according to claim 7 is characterized in that: The sewage deep denitrification and phosphorus removal treatment device also includes a fifth driving member, the inlet of the fifth driving member is connected to the sludge tank, the outlet of the fifth driving member is connected to the storage tank, and the fifth driving member can drive the sludge in the sedimentation tank to flow into the storage tank.

9. The sewage deep denitrification and dephosphorization treatment device according to claim 1, characterized in that: The sewage deep denitrification and dephosphorization treatment device also includes a sewage circulation heating component, which includes a sixth driving element, a first filtering element and a heating element that are cyclically connected in sequence; The sixth driving member is disposed in the third reaction tank, and the sixth driving member can drive the water in the third reaction tank to flow back to the third reaction tank after passing through the first filter element and the heating element; The filter element can filter impurities in the water, and the heater element can heat the water.

10. The sewage deep denitrification and dephosphorization treatment device according to claim 9, characterized in that: The sewage circulation heating component also includes a control component, a first end of the control component is connected to the outlet of the filter element, a second end of the control component is connected to the inlet of the heating element, and a third end of the control component is connected to the third reaction tank. The control component can control the first end to selectively connect to the second end and the third end.

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