Efficient biological treatment system for organic waste

Abstract

The utility model discloses an efficient biological treatment system for organic wastes. The system comprises a crusher, a first centrifugal machine, a first anaerobic tower, a second centrifugal machine, a collecting tank, a second anaerobic tower, an anaerobic ammonia oxidation reactor, a primary anaerobic tank, a primary aerobic tank, a secondary anaerobic tank, a secondary aerobic tank, a secondary sedimentation tank and a sludge collecting tank. According to the system, organic waste is subjected to solid-liquid separation and then treated respectively, so that the operation load of anaerobic digestion can be improved, and the treatment efficiency of the reactor is improved; according to the system, high-ammonia-nitrogen wastewater generated after anaerobic digestion is treated by adopting an anaerobic ammonia oxidation and two-stage A / O process, efficient denitrification can be realized, and the treated effluent can be discharged after reaching the standard. According to the system, residual sludge in the secondary sedimentation tank is discharged into the first anaerobic tower for treating solid residues, so that the residual sludge is further digested, and the amount of discharged sludge is reduced. The device can be used for efficiently treating organic wastes such as kitchen wastes, pig manure and chicken manure.

Description

Technical Field

[0001] The utility model relates to the technical field of organic waste treatment, in particular to an efficient biological treatment system for organic waste. Background Technique

[0002] With the development of the economy and the improvement of people's material living standards, the amount of food waste generated in China every day is increasing. In 2021, the national food waste generation was 1.27×10 8 t, with a year-on-year increase of 5.8%. Food waste is characterized by high water content, high organic matter content, and easy degradation. Untreated food waste exposed to the environment will cause serious environmental pollution problems.

[0003] The livestock and poultry breeding industry in China accounts for a relatively large proportion in agriculture. If the waste generated during livestock and poultry breeding cannot be effectively disposed of, it will cause serious environmental pollution. Livestock and poultry breeding waste mainly includes livestock and poultry manure, pen flushing wastewater, etc. This type of waste contains sufficient organic matter such as crude protein, lipids, etc. It is reported that the organic matter in livestock and poultry breeding waste accounts for about 81%.

[0004] At present, anaerobic digestion and aerobic composting processes are widely used in the resource treatment technologies of livestock and poultry breeding and food waste. Among them, anaerobic digestion has the advantages of low energy consumption, less secondary pollution, low operating cost, etc., and can also produce biogas to obtain benefits, which can effectively solve the environmental pollution problem of organic solid waste and realize the resource treatment of organic solid waste.

[0005] However, at the present stage, the anaerobic digestion treatment process often generates a large amount of fermented biogas residue, and the later disposal cost of the solid residue accounts for the highest proportion in the operating cost; livestock and poultry manure and food waste are directly anaerobically digested after being pulverized and mixed with solid and liquid, generally with a low organic load and low anaerobic digestion efficiency; livestock and poultry breeding and food waste have a high nitrogen content, and the effluent after anaerobic digestion contains a large amount of ammonia nitrogen, which is a typical high-ammonia-nitrogen wastewater. Therefore, it is urgent to improve the efficiency of anaerobic digestion in the process of treating livestock and poultry manure and food waste, reduce the generation of solid residue, and at the same time effectively treat the high-ammonia-nitrogen wastewater generated after anaerobic digestion to achieve the standard discharge of the wastewater. Content of the Utility Model

[0006] The purpose of the utility model is to provide an efficient biological treatment system for organic waste in view of the deficiencies of the prior art.

[0007] To achieve the above purpose, the technical solutions adopted by the utility model are specifically described as follows:

[0008] An efficient biological treatment system for organic waste, the system comprising a crusher (1), a first centrifuge (2), a first anaerobic tower (3), a second centrifuge (4), a collection tank (5), a second anaerobic tower (6), an anaerobic ammonium oxidation reactor (7), a primary anaerobic tank (8), a primary aerobic tank (9), a secondary anaerobic tank (10), a secondary aerobic tank (11), a secondary sedimentation tank (12) and a sludge collection tank (13);

[0009] Wherein, the outlet of the crusher (1) is communicated with the inlet of the first centrifuge (2), the solid residue discharge outlet of the first centrifuge (2) is communicated with the inlet of the first anaerobic tower (3), the waste liquid discharge outlet of the first centrifuge (2) is communicated with the inlet of the collection tank (5), the outlet of the first anaerobic tower (3) is communicated with the inlet of the second centrifuge (4), the waste liquid discharge outlet of the second centrifuge (4) is communicated with the inlet of the collection tank (5), the outlet of the collection tank (5) is communicated with the inlet of the second anaerobic tower (6), the outlet of the second anaerobic tower (6) is communicated with the inlet of the anaerobic ammonium oxidation reactor (7), the outlet of the anaerobic ammonium oxidation reactor (7) is communicated with the inlet of the primary anaerobic tank (8), the outlet of the primary anaerobic tank (8) is communicated with the inlet of the primary aerobic tank (9), the outlet of the primary aerobic tank (9) is communicated with the inlet of the secondary anaerobic tank (10), the outlet of the secondary anaerobic tank (10) is communicated with the inlet of the secondary aerobic tank (11), the outlet of the secondary aerobic tank (11) is communicated with the inlet of the secondary sedimentation tank (12), the outlet of the secondary sedimentation tank (12) is connected to the inlet of the sludge collection tank (13), and the outlet of the sludge collection tank (13) is communicated with the inlet of the first anaerobic tower (3);

[0010] Wherein, the first anaerobic tower (3) is a completely mixed anaerobic reactor for anaerobic digestion treatment of the solid residue after solid-liquid separation of the organic waste to remove the biodegradable organic matter in the waste residue; the feeding mode of the first anaerobic tower (3) is constant temperature continuous feeding, and the solid content of the feed is 20-25%; preferably, the organic load of the first anaerobic tower (3) is 0.8-1.5 kgVS / (m 3· d), the residence time of the solid residue in the first anaerobic tower (3) is 20 d; a stirring device is arranged inside the first anaerobic tower (3), and the stirring device is used to mix the solid residue in the first anaerobic tower (3) evenly through stirring; an internal circulation pump is arranged outside the first anaerobic tower (3), and the internal circulation pump is used to circulate the solid residue in the first anaerobic tower (3) to ensure that the solid residue in the first anaerobic tower (3) is mixed evenly without dead - angle accumulation, which is beneficial to the efficient treatment by microorganisms; an industrial on - line oxidation - reduction potential meter, an industrial on - line pH controller, an industrial on - line temperature measuring instrument and a chemical dosing tank are arranged inside the first anaerobic tower (3). The industrial on - line oxidation - reduction potential meter is associated with an alarm through a central control system and is used to monitor the oxidation - reduction potential of the solid residue in the first anaerobic tower (3). Preferably, the oxidation - reduction potential is controlled not to be greater than - 300 mV. When the oxidation - reduction potential is greater than - 300 mV, the alarm gives an alarm, and manual feeding is stopped. After the oxidation - reduction potential returns to not be greater than - 300 mV, manual feeding is resumed. The industrial on - line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system and is used to control the pH of the solid residue in the first anaerobic tower (3), providing suitable pH survival conditions for the microorganisms in the first anaerobic tower (3) and ensuring the smooth progress of the anaerobic digestion process. Preferably, the pH is controlled to be 6.8 - 8.0. The industrial on - line temperature measuring instrument is associated with an alarm through the central control system and is used to monitor the temperature in the first anaerobic tower (3), providing suitable temperature survival conditions for the microorganisms in the first anaerobic tower (3) and ensuring the smooth progress of the anaerobic digestion process. Preferably, the temperature is controlled to be 35 ± 2 °C. When the temperature is lower than 33 °C, the alarm gives an alarm, and manual heating treatment is carried out on the feed. A heat - insulating jacket is arranged outside the first anaerobic tower (3).

[0011] Among them, the second anaerobic tower (6) is an internal - circulation anaerobic reactor, which is used for the anaerobic digestion treatment of the waste liquid collected by the collection tank (5) to remove the biodegradable organic matter in the waste liquid; a centrifugal pump is used to lift the waste liquid collected by the collection tank (5) into the second anaerobic tower (6); the feeding method of the second anaerobic tower (6) is constant - temperature continuous feeding. Preferably, the organic load of the second anaerobic tower (6) is 7 - 8 kgVS / (m 3·d) (VS represents volatile solids, which is another form of organic matter. 1 g of VS is approximately equal to 1 g of COD), and the HRT is 4 d; a three-phase separator is provided at the top of the second anaerobic tower (6) for separating the sludge, water, and gas phases inside the second anaerobic tower (6). The gas generated by anaerobic digestion is discharged from the top, the treated wastewater flows out from the clarification zone, and the sludge returns to the bottom sludge layer under the action of gravity; an internal circulation pump is provided outside the second anaerobic tower (6), and the internal circulation pump is used to circulate the wastewater inside the second anaerobic tower (6) to ensure that the wastewater inside the second anaerobic tower (6) is evenly mixed without dead corners, which is beneficial to the efficient treatment by microorganisms; an industrial on-line oxidation-reduction potential meter, an industrial on-line pH controller, an industrial on-line temperature measuring instrument, and a chemical dosing tank are provided inside the second anaerobic tower (6). The industrial on-line oxidation-reduction potential meter is associated with an alarm through a central control system and is used to monitor the oxidation-reduction potential of the wastewater inside the second anaerobic tower (6). Preferably, the oxidation-reduction potential is controlled not to exceed -300 mV. When the oxidation-reduction potential is greater than -300 mV, the alarm gives an alarm, and manual feeding is stopped. After the oxidation-reduction potential returns to not exceed -300 mV, manual feeding is resumed; the industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system and is used to control the pH of the wastewater inside the second anaerobic tower (6), providing suitable pH survival conditions for the microorganisms inside the second anaerobic tower (6) and ensuring the smooth progress of the anaerobic digestion process. Preferably, the pH is controlled to be 6.8 - 8.0; the industrial on-line temperature measuring instrument is associated with an alarm through the central control system and is used to monitor the temperature inside the second anaerobic tower (6), providing suitable temperature survival conditions for the microorganisms inside the second anaerobic tower (6) and ensuring the smooth progress of the anaerobic digestion process. Preferably, the temperature is controlled to be 35 ± 2 °C. When the temperature is lower than 33 °C, the alarm gives an alarm, and manual heating treatment is carried out on the feed. A heat preservation jacket is provided outside the second anaerobic tower (6).

[0012] Among them, the anaerobic ammonium oxidation reactor (7) is used for denitrification of the effluent from the second anaerobic tower (6). The ammonia nitrogen in the effluent from the second anaerobic tower (6) undergoes partial nitrification in the anaerobic ammonium oxidation reactor (7) to generate nitrite nitrogen. The generated nitrite nitrogen directly reacts with ammonia nitrogen under the action of anaerobic ammonium oxidation bacteria in the anaerobic ammonium oxidation reactor (7) to generate nitrogen gas, achieving the removal of ammonia nitrogen; the concentration of activated sludge in the anaerobic ammonium oxidation reactor (7) is 2000 - 4000 mg / L, and the denitrification load is 1.5 - 2.0 kgN / (m 3· d); An internal circulation pump is installed outside the anammox reactor (7) to circulate the wastewater in the anammox reactor (7), ensuring that the wastewater in the anammox reactor (7) is evenly mixed without dead corners, which is conducive to the efficient treatment by microorganisms; An industrial on-line pH controller and a chemical dosing tank are installed inside the anammox reactor (7). The industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system to control the pH of the wastewater in the anammox reactor (7), providing suitable pH survival conditions for the microorganisms in the anammox reactor (7) and ensuring the smooth progress of the anammox reaction. Preferably, the pH is controlled to be 7-8; Preferably, the water temperature is controlled to be 30-35 °C; Preferably, the dissolved oxygen in the water is controlled to be 0.01-0.2 mg / L;

[0013] Furthermore, the effluent of the anammox reactor (7) sequentially enters the first-stage anaerobic tank (8), the first-stage aerobic tank (9), the second-stage anaerobic tank (10) and the second-stage aerobic tank (11); The first-stage anaerobic tank (8), the first-stage aerobic tank (9), the second-stage anaerobic tank (10) and the second-stage aerobic tank (11) form a two-stage A / O system; The denitrification and phosphorus removal of the wastewater are carried out by controlling DO and pH in the biochemical tanks of the two-stage A / O system; Nitrification reaction occurs in the aerobic tank, and the generated nitrified liquid is refluxed to the anaerobic tank for denitrification and nitrogen removal, while removing organic matter; The phosphorus-removing bacteria release phosphorus in the anaerobic tank and absorb phosphorus excessively in the aerobic tank, and then phosphorus is removed from the sewage through sludge discharge.

[0014] Among them, a nitrification liquid reflux system is arranged between the first-stage anaerobic tank (8) and the first-stage aerobic tank (9) to enable a part of the sewage in the first-stage aerobic tank (9) to flow back to the first-stage anaerobic tank (8) through the nitrification liquid reflux system for denitrification, and the nitrification liquid reflux ratio is 200%; the concentration of activated sludge in the first-stage anaerobic tank (8) is 2000-4000 mg / L; a submersible propeller is arranged in the first-stage anaerobic tank (8) to mix the wastewater in the first-stage anaerobic tank (8) evenly and flow it in a specific direction, and push the wastewater to flow to the subsequent treatment unit. Preferably, the rotation speed of the submersible propeller is 60-100 rpm, the flow pattern of the wastewater in the first-stage anaerobic tank (8) is plug flow, and the hydraulic retention time is 24 h; a submersible stirrer is arranged in the first-stage anaerobic tank (8) to mix the wastewater in the tank evenly. Preferably, the rotation speed of the submersible stirrer is 800-1000 rpm; an industrial on-line pH controller and a chemical dosing tank are arranged in the first-stage anaerobic tank (8). The industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system to control the pH of the wastewater in the first-stage anaerobic tank (8), provide suitable pH survival conditions for the microorganisms in the first-stage anaerobic tank (8), and ensure the smooth progress of the denitrification process. Preferably, the pH of the wastewater is controlled to be 7-8; preferably, the dissolved oxygen in the water is controlled to be 0.2-0.5 mg / L. The first-stage aerobic tank (9) is a completely mixed aeration tank, with an HRT of 72 h, and the concentration of activated sludge in the tank is 2000-4000 mg / L; microporous aeration discs are arranged at the bottom of the first-stage aerobic tank (9), and a Roots blower is arranged outside the first-stage aerobic tank (9). The Roots blower is connected to the microporous aeration discs through pipelines, and the Roots blower cooperates with the microporous aeration discs to blow air into the first-stage aerobic tank (9) to provide oxygen for the aerobic microorganisms in the tank; an industrial on-line dissolved oxygen meter, an industrial on-line pH controller and a chemical dosing tank are arranged inside the first-stage aerobic tank (9). The industrial on-line dissolved oxygen meter is associated with the Roots blower through the central control system, and the working frequency of the Roots blower is controlled through the value of the industrial on-line dissolved oxygen meter. Preferably, the DO in the water is controlled to be ≥2.0 mg / L; the industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system to control the pH of the wastewater in the first-stage aerobic tank (9), provide suitable pH survival conditions for the microorganisms in the first-stage aerobic tank (9), and ensure the smooth progress of the nitrification process. Preferably, the pH of the water is controlled to be 7-8.

[0015] Among them, a nitrification liquid reflux system is provided between the secondary anaerobic tank (10) and the secondary aerobic tank (11) to enable a part of the sewage in the secondary aerobic tank (11) to flow back to the secondary anaerobic tank (10) through the nitrification liquid reflux system for denitrification, and the nitrification liquid reflux ratio is 200%; the concentration of activated sludge in the secondary anaerobic tank (10) is 2000-4000 mg / L; a submersible propeller is provided in the secondary anaerobic tank (10) to mix the wastewater in the secondary anaerobic tank (10) evenly and flow it in a directed manner, and push the wastewater to flow to the subsequent treatment unit. Preferably, the rotation speed of the submersible propeller is 60-100 rpm, the flow pattern of the wastewater in the secondary anaerobic tank (10) is plug flow, and the hydraulic retention time is 24 h; a submersible agitator is provided in the secondary anaerobic tank (10) to mix the wastewater in the tank evenly. Preferably, the rotation speed of the submersible agitator is 800-1000 rpm; an industrial on-line pH controller and a chemical dosing tank are provided in the secondary anaerobic tank (10). The industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank through the central control system to control the pH of the wastewater in the secondary anaerobic tank (10), provide suitable pH survival conditions for the microorganisms in the secondary anaerobic tank (10), and ensure the smooth progress of the denitrification process. Preferably, the pH of the water is controlled to be 7-8; preferably, the dissolved oxygen in the water is controlled to be 0.2-0.5 mg / L. The secondary aerobic tank (11) is a completely mixed aeration tank with an HRT of 24 h, and the concentration of activated sludge in the tank is 2000-4000 mg / L; microporous aeration discs are provided at the bottom of the secondary aerobic tank (11), and a Roots blower is provided outside the secondary aerobic tank (11). The Roots blower is connected to the microporous aeration discs through a pipeline, and the Roots blower cooperates with the microporous aeration discs to blow air into the secondary aerobic tank (11) to provide oxygen for the aerobic microorganisms in the tank; an industrial on-line dissolved oxygen meter, an industrial on-line pH controller and a chemical dosing tank are provided inside the secondary aerobic tank (11). The industrial on-line dissolved oxygen meter is associated with the Roots blower through the central control system, and the working frequency of the Roots blower is controlled through the value of the industrial on-line dissolved oxygen meter. Preferably, the DO in the water is controlled to be ≥2.0 mg / L; the industrial on-line pH controller controls the amount of alkali or acid added to the chemical dosing tank to control the pH of the wastewater in the secondary aerobic tank (11), provide suitable pH survival conditions for the microorganisms in the secondary aerobic tank (11), and ensure the smooth progress of the nitrification process. Preferably, the pH of the water is controlled to be 7-8.

[0016] Among them, the secondary sedimentation tank (12) is a vertical sedimentation tank for separating mud and water, intercepting part of the sludge, and discharging the supernatant after separation up to the standard; sludge return systems are provided between the secondary sedimentation tank (12) and the first anaerobic tank (8) and the second anaerobic tank (10). The sludge return systems are used to return a part of the sludge intercepted by the secondary sedimentation tank (12) to the first anaerobic tank (8) and the second anaerobic tank (10), and the sludge return ratios are both 100%; the surplus sludge enters the sludge collection tank (13), and the sludge collected in the sludge collection tank (13) then enters the first anaerobic tower (3) to be mixed with the solid residue for anaerobic digestion together to achieve sludge reduction.

[0017] Among them, both the first centrifuge (2) and the second centrifuge (4) are horizontal spiral centrifugal dehydrators for separating solid and liquid of the organic waste and its products after anaerobic digestion. The water content of the separated solid residue is 60 - 80%; the solid residue separated by the first centrifuge (2) is discharged into the first anaerobic tower (3) for anaerobic digestion, and the waste liquid is discharged into the collection tank (5); the solid residue separated by the second centrifuge (4) is transported out for treatment, and the waste liquid is discharged into the collection tank (5).

[0018] Among them, the crusher (1) is used for the crushing pretreatment of the organic waste, and the organic waste after pretreatment is discharged into the first centrifuge (2) for solid - liquid separation.

[0019] The utility model realizes the separation and treatment of waste by crushing livestock and poultry manure and food waste and then separating solid and liquid, improves the efficiency of anaerobic digestion, and can optimize the solid and liquid treatment systems respectively to maximize solid reduction and pollutant removal rate; for the high - ammonia - nitrogen wastewater generated after anaerobic digestion, the process of "anaerobic ammonium oxidation + two - stage A / O" is adopted to effectively denitrify the wastewater.

[0020] Beneficial effects:

[0021] 1. Organic waste is generally treated by anaerobic digestion in a mixed way. The utility model separates solid and liquid of the organic waste and then treats them respectively, which can optimize the solid and liquid treatment processes respectively, improve the operating load of anaerobic digestion, and thus improve the treatment efficiency of the reactor.

[0022] 2. The waste liquid after anaerobic digestion of organic waste has a high nitrogen content. The utility model selects the process of "anaerobic ammonium oxidation + two - stage A / O" for treatment, which can denitrify efficiently, and the treated effluent can be discharged up to the standard.

[0023] 3. The utility model discharges the surplus sludge in the secondary sedimentation tank into the first anaerobic tower for treating the solid residue, so that the surplus sludge is further digested, thereby reducing the amount of sludge discharged. Description of the drawings

[0024] The following further specifically describes the present utility model in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present utility model will become clearer.

[0025] Figure 1 It is a flow chart of an efficient biological treatment system for organic waste of the present utility model. Specific embodiments

[0026] The following further illustrates the present utility model according to the following embodiments. It should be understood that the following embodiments are only used to illustrate the present utility model and do not limit the present utility model.

[0027] As Figure 1 shown, it is a flow chart of the treatment system for kitchen waste in this embodiment. The kitchen waste is pre-crushed by a crusher 1 and then discharged into a first centrifuge 2 for solid-liquid separation. The separated solid residue enters a first anaerobic tower 3 from the solid residue discharge port of the first centrifuge 2 for anaerobic digestion to reduce sludge, and the waste liquid enters a collection tank 5 from the waste liquid discharge port of the first centrifuge 2; the waste residue after anaerobic digestion in the first anaerobic tower 3 is discharged into a second centrifuge 4 for solid-liquid separation again. The separated solid residue is discharged from the solid residue discharge port of the second centrifuge 4 and transported for external treatment, and the waste liquid is discharged into the collection tank 5 from the waste liquid discharge port of the second centrifuge 4; the waste liquid collected in the collection tank 5 is discharged into a second anaerobic tower 6 for anaerobic digestion, and the waste water after anaerobic digestion is discharged into an anaerobic ammonium oxidation reactor 7 for anaerobic ammonium oxidation reaction to remove nitrogen. Then, the waste water enters a first anaerobic tank 8, a first aerobic tank 9, a second anaerobic tank 10, and a second aerobic tank 11 in sequence for nitrification and denitrification reactions to remove nitrogen; a nitrification liquid reflux system is provided between the first anaerobic tank 8 and the first aerobic tank 9, and between the second anaerobic tank 10 and the second aerobic tank 11. A part of the sewage after nitrification occurs in the aerobic tank is refluxed to the anaerobic tank through the nitrification liquid reflux system for denitrification; the sewage treated by the two-stage A / O system enters a secondary sedimentation tank 12 for sludge-water separation, and the supernatant is discharged up to standard; a sludge reflux system is provided between the secondary sedimentation tank 12 and the first anaerobic tank 8 and the second anaerobic tank 10 for refluxing part of the sludge in the secondary sedimentation tank 12 to the first anaerobic tank 8 and the second anaerobic tank 10, and the surplus sludge is discharged into a sludge collection tank 13. The sludge in the sludge collection tank 13 is discharged into the first anaerobic tower 3 for anaerobic digestion together with the solid residue.

[0028] The method for treating kitchen waste in this embodiment is as follows:

[0029] After the kitchen waste is collected, the large waste is first crushed by a crusher 1, and then solid-liquid separation is carried out by a first centrifuge 2, and then the solid and liquid phases are treated separately. The waste liquid enters the collection tank 5, and the solid residue enters the first anaerobic tower 3 for anaerobic digestion.

[0030] The solid phase enters the first anaerobic tower 3 for anaerobic digestion. The solid content of the feed is 25%. Mechanical stirring is used to mix the solid residue evenly, with a stirring intensity of 60 ± 10 r / min. The organic loading is 0.8 - 1.5 kgVS / (m 3 ·d). The residence time of the solid residue in the first anaerobic tower 3 is 20 d. The digestion temperature is controlled at 35 ± 2 °C, and the pH is 6.8 - 8.5.

[0031] After anaerobic digestion, the discharged material is separated by a second centrifuge 4 into solid and liquid phases. The solid residue is transported out for treatment, and the waste liquid enters the collection tank 5.

[0032] The waste liquid is first collected by the collection tank 5 and then pumped by a centrifugal pump to enter the second anaerobic tower 6 for anaerobic digestion. The wastewater enters in a bottom - up manner and is separated into sludge, water, and gas phases through a three - phase separator at the top of the second anaerobic tower 6. The gas generated by anaerobic digestion is discharged from the top, the effluent flows out from the clarification zone, and the sludge returns to the bottom sludge layer under the action of gravity. The temperature is controlled at 35 ± 2 °C, the organic loading is 7 - 8 kgVS / (m 3 ·d), and the HRT is 4 d.

[0033] The effluent from the second anaerobic tower 6 enters the anaerobic ammonium oxidation reactor 7. The ammonia nitrogen in the wastewater undergoes partial nitrification in the anaerobic ammonium oxidation reactor 7 to generate nitrite nitrogen. The generated nitrite nitrogen and ammonia nitrogen directly react under the action of anaerobic ammonium oxidation bacteria in the anaerobic ammonium oxidation reactor 7 to generate nitrogen, achieving the removal of ammonia nitrogen from the wastewater. The denitrification load of the anaerobic ammonium oxidation reactor 7 is 1.5 - 2.0 kgN / (m 3 ·d), the water temperature is 30 - 35 °C, the DO is 0.01 - 0.2 mg / L, and the concentration of activated sludge in the reactor is 2000 - 4000 mg / L.

[0034] The effluent from the anaerobic ammonium oxidation reactor 7 then enters a two - stage A / O system, namely a first - stage anaerobic tank 8, a first - stage aerobic tank 9, a second - stage anaerobic tank 10, and a second - stage aerobic tank 11. The denitrification and phosphorus removal of the wastewater are carried out by controlling the DO and pH in the tanks. Nitrification occurs in the aerobic stage, and the generated nitrified liquid is refluxed to the anaerobic stage for denitrification, while removing organic matter at the same time. Phosphorus - accumulating bacteria release phosphorus in the anaerobic stage and absorb phosphorus excessively in the aerobic stage, and then phosphorus is removed from the sewage through sludge discharge. The flow pattern of the wastewater in the first - stage anaerobic tank 8 and the second - stage anaerobic tank 10 is plug - flow, and the hydraulic retention time of both is 24 h. The pH in the tanks is controlled at 7 - 8, the DO is 0.2 - 0.5 mg / L, and the concentration of activated sludge in the tanks is 2000 - 4000 mg / L. The first - stage aerobic tank 9 and the second - stage aerobic tank 11 are completely mixed aeration tanks, and the hydraulic retention times are 72 h and 24 h respectively. The pH in the tanks is controlled at 7 - 8, the DO ≥ 2.0 mg / L, the nitrified liquid reflux ratios are both 200%, and the concentration of activated sludge in the tanks is 2000 - 4000 mg / L.

[0035] The effluent from the secondary aerobic tank 11 enters the secondary sedimentation tank 12 for sedimentation to achieve the separation of mud and water. The secondary sedimentation tank is a vertical sedimentation tank; the supernatant is discharged up to the standard, and a part of the sludge is refluxed to the primary anaerobic tank 8 and the secondary anaerobic tank 10 through the sludge reflux system, and the sludge reflux ratios are both 100%. The remaining sludge is collected by the sludge collection tank 13 and then enters the first anaerobic tower 3 to be mixed with the solid residue for sludge reduction.

[0036] Adopt such as Figure 1 The shown organic waste treatment system is used to treat a certain kitchen waste. After solid-liquid separation by the first centrifuge 2, the solid content rate of the solid phase is about 25%, and the total nitrogen content is about 11.0 g / L; the collection tank 5 collects the waste liquid separated by the first centrifuge 2 and the second centrifuge 4. The COD content of the wastewater in the collection tank 5 is 130000 mg / L, and the total nitrogen content is about 5 g / L. The total nitrogen content in the effluent from the second anaerobic tower 6 is relatively high, about 4.5 g / L. Table 1 shows the removal rate of the volatile organic solid content (VS%) in the solid residue by the first anaerobic tower 3 of the system. It can be seen from Table 1 that after being treated by the first anaerobic tower 3, the VS removal rate in the solid residue of the organic waste is as high as 77.6%, greatly reducing the organic matter content in the solid residue and achieving the removal of pollutants in the solid residue.

[0037] Table 2 shows the water quality parameters of the influent and effluent of each section of the system. It can be seen from Table 2 that after the wastewater in the organic waste is treated by the second anaerobic tower 6, the anaerobic ammonium oxidation reactor 7 and the two-stage A / O system, the effluent COD, ammonia nitrogen and total nitrogen contents are reduced to 210 mg / L, 27 mg / L and 65 mg / L respectively, and the effluent water quality reaches the third-level discharge standard in the Comprehensive Wastewater Discharge Standard (GB 8978—1996).

[0038] Table 3 shows the water quality parameters of the effluent of each section during the stable operation of the system. It can be seen from Table 3 that during the stable operation of the system, the effluent COD content of the system is stable below 300 mg / L, the ammonia nitrogen content is stable below 40 mg / L, and the total nitrogen content is stable below 75 mg / L, indicating that when the system operates stably, the effluent water quality of the system can always reach the third-level discharge standard in the Comprehensive Wastewater Discharge Standard (GB 8978—1996).

[0039] The above results show that the organic waste treatment system of the present utility model can effectively treat the kitchen waste, and the effluent water quality is better and can reach the standard for discharge.

[0040] Table 1 Removal effect of the first anaerobic tower (3) on the volatile organic solid content (VS%) in the solid residue

[0041]

[0042] Table 2 Water quality parameters of the influent and effluent of each section

[0043]

[0044]

[0045] Note: The influent COD, ammonia nitrogen and total nitrogen contents in the two-stage A / O system in the table are the COD, ammonia nitrogen and total nitrogen contents of the influent to the first-stage anaerobic tank 8; the effluent COD, ammonia nitrogen and total nitrogen contents are the COD, ammonia nitrogen and total nitrogen contents of the influent to the second-stage aerobic tank 11.

[0046] Table 3 Effluent water quality parameters of each section during stable operation (unit: mg / L)

[0047]

[0048]

[0049] Note: The effluent COD, ammonia nitrogen and total nitrogen contents in the two-stage A / O system in the table are the COD, ammonia nitrogen and total nitrogen contents of the effluent from the second-stage aerobic tank 11.

[0050] The present utility model provides an idea and method for an efficient biological treatment system for organic waste. There are many methods and ways to specifically implement this technical solution. The above is only the preferred embodiment of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model. Each component not clearly defined in this embodiment can be realized by existing technologies.

Claims

1. An efficient biological treatment system for organic waste, characterized in that, It includes a second anaerobic tower (6), an anammox reactor (7), a first anaerobic tank (8), a first aerobic tank (9), a second anaerobic tank (10) and a second aerobic tank (11) which are connected in sequence; It includes a crusher (1), a first centrifuge (2), a first anaerobic tower (3) and a second centrifuge (4) which are connected in sequence; wherein, the solid residue discharge port of the first centrifuge (2) is connected to the inlet of the first anaerobic tower (3); It includes a collection tank (5), a secondary sedimentation tank (12) and a sludge collection tank (13); Wherein, the waste liquid discharge ports of the first centrifuge (2) and the second centrifuge (4) are both connected to the inlet of the collection tank (5); the outlet of the collection tank (5) is connected to the inlet of the second anaerobic tower (6); the outlet of the second aerobic tank (11) is connected to the inlet of the secondary sedimentation tank (12), the outlet of the secondary sedimentation tank (12) is connected to the inlet of the sludge collection tank (13), and the outlet of the sludge collection tank (13) is connected to the inlet of the first anaerobic tower (3).

2. The high-efficiency biological treatment system for organic waste according to claim 1, wherein The second anaerobic tower (6) is an internal circulation anaerobic reactor, and a three-phase separator is arranged at the top of the second anaerobic tower (6).

3. An efficient biological treatment system for organic waste according to claim 1, characterized in that, A nitrification liquid reflux system is arranged between the first anaerobic tank (8) and the first aerobic tank (9), and between the second anaerobic tank (10) and the second aerobic tank (11).

4. An efficient biological treatment system for organic waste according to claim 1, characterized in that, The first anaerobic tower (3) is a completely mixed anaerobic reactor.

5. An efficient biological treatment system for organic waste according to claim 1, characterized in that, A sludge reflux system is arranged between the secondary sedimentation tank (12) and the first anaerobic tank (8), and between the secondary sedimentation tank (12) and the second anaerobic tank (10).

6. An efficient biological treatment system for organic waste according to claim 1, characterized in that, Both the first centrifuge (2) and the second centrifuge (4) are horizontal screw centrifugal dehydrators.

7. An efficient biological treatment system for organic waste according to claim 1, characterized in that, A stirring device is arranged inside the first anaerobic tower (3), and an internal circulation pump is arranged outside; internal circulation pumps are arranged outside both the second anaerobic tower (6) and the anammox reactor (7); submersible propellers and submersible agitators are arranged inside both the first anaerobic tank (8) and the second anaerobic tank (10); microporous aeration discs are arranged at the bottom of both the first aerobic tank (9) and the second aerobic tank (11), and Roots blowers are arranged outside both the first aerobic tank (9) and the second aerobic tank (11), and the Roots blowers are connected to the microporous aeration discs through pipelines.

8. An efficient biological treatment system for organic waste according to claim 1, characterized in that, Redox potential meters, pH controllers and temperature measuring instruments are arranged inside both the first anaerobic tower (3) and the second anaerobic tower (6); pH controllers are arranged inside the anammox reactor (7), the first anaerobic tank (8) and the second anaerobic tank (10); pH controllers and dissolved oxygen meters are arranged inside both the first aerobic tank (9) and the second aerobic tank (11).

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