Multi-source organic solid waste and anaerobic digestion effluent efficient deep denitrification system and process

Abstract

The present application relates to high ammonia-nitrogen wastewater treatment technical field, especially to a kind of multi-source organic solid waste cooperates anaerobic digestion biogas liquid high-efficiency deep denitrification system and process.The multi-source organic solid waste to be treated cooperates anaerobic digestion biogas liquid first into anaerobic treatment unit and carries out denitrification process;Anaerobic treatment unit effluent flows into aerobic treatment unit to remove residual organic matter and part of suspended solids, effluent part is introduced into suspended solids treatment unit and is chemically conditioned and centrifuged to strengthen the removal of suspended solids, another part of effluent is backflowed to anaerobic treatment unit;Suspended solids treatment unit effluent enters PN-A treatment unit and carries out short-cut nitrification-anammox process to strengthen ammonia-nitrogen removal, part of effluent is backflowed to anaerobic treatment unit, further strengthen nitrate nitrogen removal, and the remaining part is directly discharged.The present application overcomes the low carbon-nitrogen ratio of digestion biogas liquid, complex composition and other adverse conditions, and does not need to add organic carbon source, aeration amount is lower, greatly reduces treatment cost and energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-ammonia-nitrogen wastewater treatment, and particularly relates to a multi-source organic solid waste synergistic anaerobic digestion biogas slurry high-efficiency deep denitrification system and process. BACKGROUND

[0002] With the continuous development of urbanization and economic production, the output of high-moisture organic solid waste represented by kitchen waste, kitchen garbage and excess sludge is increasing. At present, the anaerobic digestion process is usually used to realize the treatment and resource utilization of organic solid waste. However, a large amount of anaerobic digestion biogas slurry containing high-concentration ammonia nitrogen and a certain concentration of phosphorus will be produced after the multi-source organic solid waste synergistic anaerobic digestion process is completed. If it cannot be effectively treated, it will easily cause the eutrophication of the receiving water body. Therefore, the high-efficiency deep denitrification of biogas slurry is of great significance to the final disposal of multi-source organic solid waste and the protection of the surrounding environment.

[0003] Biological denitrification is still the most effective, economical and feasible wastewater nitrogen removal process. Due to the high-nitrogen and low-carbon characteristics of biogas slurry, under the condition of not adding organic carbon sources such as sodium acetate, the traditional nitrification and denitrification path cannot realize the high-efficiency deep denitrification of biogas slurry. Therefore, the application of the anaerobic ammonia oxidation process which can realize autotrophic denitrification in the anaerobic digestion biogas slurry denitrification has attracted more and more attention. The anaerobic ammonia oxidation process usually takes ammonia nitrogen as the electron donor and nitrite nitrogen as the electron acceptor to convert nitrogen into nitrogen gas and remove it. The nitrogen in the anaerobic digestion biogas slurry mainly exists in the form of ammonia nitrogen (the ammonia nitrogen concentration is usually 2000-3000 mg / L), and the nitrite nitrogen required by the anaerobic ammonia oxidation process does not exist in large quantities in the biogas slurry. Therefore, the ammonia nitrogen in the biogas slurry is usually partially converted into nitrite nitrogen through the short-cut nitrification process, and then the anaerobic ammonia oxidation process is carried out, that is, the two-stage short-cut nitrification anaerobic ammonia oxidation denitrification process. However, the two-stage process does not have advantages in terms of land occupation, capital investment, operation and maintenance, etc.

[0004] In the engineering scale, the stability of the anaerobic ammonia oxidation system is poor. The anaerobic ammonia oxidation bacteria are easily impacted by factors such as suspended solids (SS), organic matter (BOD) and other microorganisms in the wastewater, and the anaerobic digestion biogas slurry usually has high SS, a certain concentration of organic matter and a complex microbial composition. Therefore, the method for removing interference factors and enhancing the operation stability still needs to be studied, otherwise the development of the anaerobic digestion biogas slurry high-efficiency deep denitrification process will be limited.

[0005] In addition, due to the limitation of its own characteristics, the anaerobic ammonia oxidation process will still produce a small amount of nitrate nitrogen while denitrifying. In the case of high ammonia nitrogen concentration in the influent, the nitrate nitrogen in the effluent is high, which makes it impossible to achieve the goal of deep denitrification, and further removal of nitrate nitrogen is needed to meet the discharge requirements. SUMMARY

[0006] In order to solve the shortcomings of the anaerobic digestion of biogas slurry based on the anaerobic ammonia oxidation process, the purpose of the present application is to provide a multi-source organic solid waste and anaerobic digestion of biogas slurry efficient deep denitrification system and process, the multi-source organic solid waste and anaerobic digestion of biogas slurry to be treated first enters the anaerobic treatment unit for denitrification process; the effluent of the anaerobic treatment unit flows into the aerobic treatment unit to remove residual organic matter and part of suspended solids, part of the effluent is introduced into the suspended solids treatment unit for chemical conditioning and centrifugal separation to strengthen the removal of suspended solids, the other part of the effluent is returned to the anaerobic treatment unit; the effluent of the suspended solids treatment unit enters the PN-A treatment unit for short-cut nitrification-anaerobic ammonia oxidation process to strengthen the removal of ammonia nitrogen, part of the effluent is returned to the anaerobic treatment unit to further strengthen the removal of nitrate nitrogen, and the remaining part is directly discharged. The present application overcomes the complex composition of the digestion of biogas slurry, many interference factors and other adverse conditions, and does not need to add organic carbon source, the aeration amount is low, the treatment cost and energy consumption are greatly reduced, so as to solve the problems of incomplete denitrification and poor stability in the current biogas slurry biological treatment technology.

[0007] The purpose of the present application can be realized by the following technical solutions:

[0008] The first purpose of the present application is to provide a multi-source organic solid waste and anaerobic digestion of biogas slurry efficient deep denitrification system, which comprises an anaerobic treatment unit, an aerobic treatment unit, a suspended solids treatment unit and a PN-A treatment unit;

[0009] The anaerobic treatment unit comprises an anaerobic reactor and a first constant temperature control device, and the first constant temperature control device is arranged outside the anaerobic reactor;

[0010] The aerobic treatment unit comprises an aerobic reactor, a first aeration device, a first dissolved oxygen detection electrode, a second constant temperature control device and a first reflux device, the second constant temperature control device is arranged outside the aerobic reactor, and the aerobic reactor is connected with the first aeration device, the first dissolved oxygen detection electrode and the first reflux device;

[0011] The suspended solids treatment unit comprises a full-automatic coagulation device and a centrifugal separation device; the full-automatic coagulation device is connected with the centrifugal separation device;

[0012] The PN-A treatment unit comprises a PN-A reactor, a second aeration device, a second dissolved oxygen detection electrode, a third constant temperature control device, a second reflux device and a pH detection electrode, the third constant temperature control device is arranged outside the PN-A reactor, and the PN-A reactor is connected with the second aeration device, the second dissolved oxygen detection electrode, the pH detection electrode and the second reflux device;

[0013] The multi-source organic solid waste and anaerobic digestion biogas are introduced into the anaerobic reactor through the inlet of the anaerobic reactor, and the outlet of the anaerobic reactor is connected with the inlet of the aerobic reactor; the outlet of the aerobic reactor is connected with the inlet of the automatic coagulation device, and the outlet of the aerobic reactor is also connected with the inlet of the anaerobic reactor through the first reflux device; the outlet of the automatic coagulation device is connected with the inlet of the centrifugal separation device, the outlet of the centrifugal separation device is connected with the inlet of the PN-A reactor, the outlet of the PN-A reactor is connected with the water outlet, and the outlet of the PN-A reactor is also connected with the inlet of the anaerobic reactor through the second reflux device.

[0014] In an embodiment of the present application, part of the effluent in the aerobic treatment unit is refluxed to the anaerobic treatment unit to strengthen the removal of nitrate nitrogen and organic matter.

[0015] In an embodiment of the present application, part of the effluent in the PN-A treatment unit is refluxed to the anaerobic treatment unit to strengthen the removal of nitrate nitrogen, so as to remove the nitrate nitrogen by-product of the anaerobic ammonia oxidation process as much as possible.

[0016] In an embodiment of the present application, the anaerobic treatment unit is used for removing nitrate nitrogen and consuming organic matter through the denitrification process;

[0017] The aerobic treatment unit is used for treating the residual organic matter in the anaerobic treatment unit (including removing the organic matter which is not utilized by the microorganism in the previous unit but is biologically available, and decomposing part of the difficultly biologically available macromolecular organic matter into organic matter with stronger biodegradability) and removing part of the SS; at the same time, the aerobic treatment unit has part of nitrification function, and accumulates nitrite nitrogen for the subsequent process;

[0018] The suspended matter treatment unit is used for further removing the residual SS in the wastewater, and killing the microorganism in the wastewater (chemical conditioning process), so as to avoid the interference of the complex microorganism on the operation stability of the subsequent PN-A treatment unit;

[0019] The PN-A treatment unit is used for carrying out the short-cut nitrification-anaerobic ammonia oxidation treatment process.

[0020] In an embodiment of the present application, the multi-source organic solid waste and anaerobic digestion biogas is the biogas produced after two or three kinds of solid waste in kitchen garbage, kitchen waste or residual sludge are mixed and treated by an anaerobic digestion system;

[0021] The COD of the multi-source organic solid waste and anaerobic digestion biogas is 7000-10000 mg / L, the ammonia nitrogen content is 1500-2500 mg / L, the total nitrogen content is 4000-6000 mg / L, and C / N < 2.

[0022] In an embodiment of the present application, the anaerobic reactor is provided with light autotrophic filler; the light autotrophic filler is selected from one or more of light sponge, fluffy fiber ball or EPS foamed plastic;

[0023] The density of the light autotrophic filler is 0.1-0.3g / cm 3 , and the filling rate is 30-50%.

[0024] In an embodiment of the present application, the light autotrophic filler is loaded with one or more of sulfur-based material or iron-based material;

[0025] The sulfur-based material is selected from one or more of sulfur, pyrite and sphalerite;

[0026] The iron-based material is selected from one or more of siderite, reduced iron powder and iron shavings.

[0027] In an embodiment of the present application, the light autotrophic filler is used to strengthen microbial growth and provide autotrophic denitrification electron donor substance.

[0028] In an embodiment of the present application, in the anaerobic reactor, the dissolved oxygen concentration is 0.01-0.20mg / L, the pH is 7.0-8.0, and the temperature is 20-30℃.

[0029] In an embodiment of the present application, in the aerobic reactor, the dissolved oxygen concentration is 0.8-2.0mg / L, the pH is 8.0-8.5, and the temperature is 30-35℃.

[0030] In an embodiment of the present application, in the aerobic treatment unit, the sludge concentration is 2500-3500mg / L.

[0031] In an embodiment of the present application, the centrifugal separation device has a water effluent suspended solid content <1000mg / L.

[0032] In an embodiment of the present application, in the PN-A reactor, the dissolved oxygen concentration is 0.2-0.8mg / L, the pH is 8.0-8.5, and the temperature is 33-35℃.

[0033] In an embodiment of the present application, the PN-A treatment unit adopts PN-A granular sludge technology.

[0034] The second object of the present application is to provide a multi-source organic solid waste and anaerobic digestion biogas liquid synergistic efficient deep denitrification process, comprising the following steps:

[0035] (1) The multi-source organic solid waste and anaerobic digestion biogas liquid to be treated first enters the anaerobic treatment unit for denitrification process;

[0036] (2) The effluent from the anaerobic treatment unit is fed into the aerobic treatment unit to remove residual organic matter and part of the suspended solids;

[0037] (3) Part of the effluent from the aerobic treatment unit is introduced into the suspended matter treatment unit for chemical conditioning and centrifugal separation to enhance the removal of suspended solids, and the other part of the effluent is returned to the anaerobic treatment unit;

[0038] (4) The effluent from the suspended matter treatment unit is fed into the PN-A treatment unit for a short-cut nitrification-anammox process to enhance the removal of ammonia nitrogen, part of the effluent is returned to the anaerobic treatment unit to further enhance the removal of nitrate nitrogen, and the remaining part is directly discharged.

[0039] In an embodiment of the present application, in step (3), the return flow of the return water from the aerobic treatment unit to the anaerobic treatment unit accounts for 60-80% of the total flow of the effluent from the aerobic treatment unit;

[0040] In step (4), the return flow of the return water from the PN-A treatment unit to the anaerobic treatment unit has a return flow rate of 200-300% of the influent flow rate of the multi-source organic solid waste and the biogas slurry from anaerobic digestion, so as to enhance the removal of nitrate nitrogen and improve the total nitrogen removal rate of the entire system.

[0041] In an embodiment of the present application, in the PN-A treatment unit, a short-cut nitrification-anammox granular sludge process is adopted, and a composite magnesium salt medicament is regularly added to maintain the stability and growth of the granular sludge.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] (1) Traditional biological denitrification processes often require wastewater to have a high C / N to ensure the progress and effect of the denitrification process, so external addition of organic carbon sources such as sodium acetate is often required. In the present application, efficient and deep denitrification of anaerobic digestion biogas slurry with C / N < 2 is achieved mainly by autotrophic process without adding any form of carbon source, which effectively reduces the denitrification cost. Moreover, the short-cut nitrification-anammox process is adopted in the PN-A treatment unit of the present application, which realizes short-cut nitrification and autotrophic removal of ammonia nitrogen in one step, effectively improving the denitrification efficiency.

[0044] (2) The present application sets a front anaerobic treatment unit, which uses the organic matter in the influent as a carbon source to remove the nitrate nitrogen (mainly produced by the anaerobic ammonium oxidation process) returned from the PN-A treatment unit, i.e. to achieve deep nitrogen removal and remove organic matter, thereby reducing the risk of organic matter impacting the subsequent anaerobic ammonium oxidation process.

[0045] (3) The present application is provided with an aerobic treatment unit, which can further reduce the organic matter and suspended solids in the wastewater on the basis of the previous step process, so as to avoid the impact of these pollutants on the PN-A treatment unit (short-cut nitrification-anaerobic ammonia oxidation process); at the same time, the unit has the function of short-cut nitrification, and is expected to accumulate nitrite nitrogen, so as to reduce the aeration amount of the PN-A treatment unit and the pressure of the short-cut nitrification process. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a multi-source organic solid waste and anaerobic digestion biogas liquid efficient deep denitrification system schematic diagram of the present application;

[0047] Figure 2 It is a multi-source organic solid waste and anaerobic digestion biogas liquid efficient deep denitrification process schematic diagram of the present application;

[0048] Figure 3 It is a multi-source organic solid waste and anaerobic digestion biogas liquid efficient deep denitrification system schematic diagram of the present application;

[0049] In the figure, the label is: 1, anaerobic treatment unit; 2, aerobic treatment unit; 3, suspended solids treatment unit; 4, PN-A treatment unit; 5, automatic control device; 6, pH automatic adjusting device; 11, anaerobic reactor; 12, first constant temperature control device; 21, aerobic reactor; 22, second constant temperature control device; 23, first dissolved oxygen detection electrode; 24, first aeration device; 25, first reflux device; 31, automatic coagulation device; 32, centrifugal separation device; 41, PN-A reactor; 42, third constant temperature control device; 43, second dissolved oxygen detection electrode; 44, second aeration device; 45, second reflux device; 46, pH detection electrode; 311, dosing port; 321, slag discharge port. DETAILED DESCRIPTION

[0050] The present application provides a multi-source organic solid waste and anaerobic digestion biogas liquid efficient deep denitrification system, which comprises an anaerobic treatment unit, an aerobic treatment unit, a suspended solids treatment unit and a PN-A treatment unit;

[0051] The anaerobic treatment unit comprises an anaerobic reactor and a first constant temperature control device, and the first constant temperature control device is arranged outside the anaerobic reactor;

[0052] The aerobic treatment unit comprises an aerobic reactor, a first aeration device, a first dissolved oxygen detection electrode, a second constant temperature control device and a first reflux device, the second constant temperature control device is arranged outside the aerobic reactor, and the aerobic reactor is connected with the first aeration device, the first dissolved oxygen detection electrode and the first reflux device;

[0053] The suspension treatment unit comprises a full-automatic coagulation device and a centrifugal separation device; the full-automatic coagulation device is connected to the centrifugal separation device;

[0054] The PN-A treatment unit comprises a PN-A reactor, a second aeration device, a second dissolved oxygen detection electrode, a third constant temperature control device, a second reflux device and a pH detection electrode; the third constant temperature control device is arranged outside the PN-A reactor; the PN-A reactor is connected to the second aeration device, the second dissolved oxygen detection electrode, the pH detection electrode and the second reflux device;

[0055] The multi-source organic solid waste is fed into the anaerobic reactor through the anaerobic reactor inlet; the anaerobic reactor outlet is connected to the aerobic reactor inlet; the aerobic reactor outlet is connected to the full-automatic coagulation device inlet; the aerobic reactor outlet is also connected to the anaerobic reactor inlet through the first reflux device; the full-automatic coagulation device outlet is connected to the centrifugal separation device inlet; the centrifugal separation device outlet is connected to the PN-A reactor inlet; the PN-A reactor outlet is connected to the water outlet; the PN-A reactor outlet is also connected to the anaerobic reactor inlet through the second reflux device.

[0056] In an embodiment of the present application, part of the effluent in the aerobic treatment unit is refluxed to the anaerobic treatment unit to enhance the removal of nitrate nitrogen and organic matter.

[0057] In an embodiment of the present application, part of the effluent in the PN-A treatment unit is refluxed to the anaerobic treatment unit to enhance the removal of nitrate nitrogen, so as to remove the nitrate nitrogen by-product of the anaerobic ammonia oxidation process as much as possible.

[0058] In an embodiment of the present application, the anaerobic treatment unit is used for removing nitrate nitrogen and consuming organic matter through the denitrification process;

[0059] The aerobic treatment unit is used for treating the residual organic matter in the anaerobic treatment unit (including removing the organic matter that is not utilized by the microorganism in the previous unit but is biodegradable and decomposing part of the difficultly biodegradable macromolecular organic matter into organic matter with stronger biodegradability) and removing part of the SS; at the same time, the aerobic treatment unit has part of the nitrification function and accumulates nitrite nitrogen for the subsequent process;

[0060] The suspension treatment unit is used for further removing the residual SS in the wastewater and killing the microorganism in the wastewater (chemical conditioning process), so as to avoid the interference of the complex microorganism on the operation stability of the subsequent PN-A treatment unit;

[0061] The PN-A treatment unit is used for carrying out the short-cut nitrification-anaerobic ammonia oxidation treatment process.

[0062] In an embodiment of the present application, the multi-source organic solid waste synergistic anaerobic digestion biogas slurry is a biogas slurry produced by mixing two or three of kitchen waste, food waste or residual sludge and treating the mixture in an anaerobic digestion system.

[0063] The COD of the multi-source organic solid waste synergistic anaerobic digestion biogas slurry is 7000-10000 mg / L, the ammonia nitrogen content is 1500-2500 mg / L, the total nitrogen content is 4000-6000 mg / L, and C / N < 2.

[0064] In an embodiment of the present application, the anaerobic reactor is provided with light autotrophic filler; the light autotrophic filler is selected from one or more of light sponge, fluffy fiber ball or EPS foamed plastic;

[0065] The density of the light autotrophic filler is 0.1-0.3 g / cm 3 , and the filling rate is 30-50%.

[0066] In an embodiment of the present application, the light autotrophic filler is loaded with one or more of sulfur-based materials or iron-based materials;

[0067] The sulfur-based material is selected from one or more of sulfur, pyrite and sphalerite;

[0068] The iron-based material is selected from one or more of siderite, reduced iron powder and iron shavings.

[0069] In an embodiment of the present application, the light autotrophic filler is used to strengthen microbial growth and provide autotrophic denitrification electron donor substances.

[0070] In an embodiment of the present application, in the anaerobic reactor, the dissolved oxygen concentration is 0.01-0.20 mg / L, the pH is 7.0-8.0, and the temperature is 20-30℃.

[0071] In an embodiment of the present application, in the aerobic reactor, the dissolved oxygen concentration is 0.8-2.0 mg / L, the pH is 8.0-8.5, and the temperature is 30-35℃.

[0072] In an embodiment of the present application, in the aerobic treatment unit, the sludge concentration is 2500-3500 mg / L.

[0073] In an embodiment of the present application, the suspended solid content of the centrifugal separation device effluent is <1000 mg / L.

[0074] In an embodiment of the present application, in the PN-A reactor, the dissolved oxygen concentration is 0.2-0.8 mg / L, the pH is 8.0-8.5, and the temperature is 33-35℃.

[0075] In one embodiment of the present application, the PN-A treatment unit adopts the PN-A granular sludge technology.

[0076] The present application provides a multi-source organic solid waste and anaerobic digestion biogas slurry efficient deep denitrification process, comprising the following steps:

[0077] (1) The multi-source organic solid waste and anaerobic digestion biogas slurry to be treated first enters the anaerobic treatment unit for denitrification process;

[0078] (2) The effluent from the anaerobic treatment unit flows into the aerobic treatment unit to remove residual organic matter and part of the suspended solids;

[0079] (3) Part of the effluent from the aerobic treatment unit is introduced into the suspended solids treatment unit for chemical conditioning and centrifugal separation to enhance the removal of suspended solids, and the other part of the effluent is returned to the anaerobic treatment unit;

[0080] (4) The effluent from the suspended solids treatment unit enters the PN-A treatment unit for short-cut nitrification and anaerobic ammonia oxidation process to enhance the removal of ammonia nitrogen, part of the effluent is returned to the anaerobic treatment unit to further enhance the removal of nitrate nitrogen, and the remaining part is directly discharged.

[0081] In one embodiment of the present application, in step (3), the reflux flow rate of the reflux water from the aerobic treatment unit to the anaerobic treatment unit accounts for 60-80% of the total flow rate of the effluent from the aerobic treatment unit;

[0082] In step (4), the reflux flow rate of the reflux water from the PN-A treatment unit to the anaerobic treatment unit is 200-300% of the influent flow rate of the multi-source organic solid waste and anaerobic digestion biogas slurry to be treated, to enhance the removal of nitrate nitrogen and improve the total nitrogen removal rate of the entire system.

[0083] In one embodiment of the present application, in the PN-A treatment unit, short-cut nitrification and anaerobic ammonia oxidation granular sludge process is adopted, and composite magnesium salt reagent is regularly added to maintain the stability and growth of the granular sludge.

[0084] The present application will be described in detail below with reference to the accompanying drawings and specific examples.

[0085] In the following examples, unless otherwise specified, the reagents used are commercially available reagents; the detection methods and means are conventional detection methods and means in the art.

[0086] Example 1

[0087] This example provides a multi-source organic solid waste and anaerobic digestion biogas slurry efficient deep denitrification system.

[0088] As Figure 1As shown, a multi-source organic solid waste anaerobic digestion biogas liquid efficient deep denitrification system, comprising an anaerobic treatment unit 1, an aerobic treatment unit 2, a suspended matter treatment unit 3 and a PN-A treatment unit 4;

[0089] The anaerobic treatment unit 1 comprises an anaerobic reactor 11 and a first constant temperature control device 12, and the first constant temperature control device 12 is arranged outside the anaerobic reactor 11;

[0090] The aerobic treatment unit 2 comprises an aerobic reactor 21, a first aeration device 24, a first dissolved oxygen detection electrode 23, a second constant temperature control device 22 and a first reflux device 25, the second constant temperature control device 22 is arranged outside the aerobic reactor 21, the aerobic reactor 21 is provided with an aeration disc and is connected with the first aeration device 24, and the aerobic reactor 21 is also connected with the first dissolved oxygen detection electrode 23 and the first reflux device 25;

[0091] The suspended matter treatment unit 3 comprises a full-automatic coagulation device 31 and a centrifugal separation device 32; the full-automatic coagulation device 31 is connected with the centrifugal separation device 32; the full-automatic coagulation device 31 is provided with a dosing port 311 for adding a composite magnesium salt reagent, and the centrifugal separation device 32 is provided with a residue discharge port 321;

[0092] The PN-A treatment unit 4 comprises a PN-A reactor 41, a second aeration device 44, a second dissolved oxygen detection electrode 43, a third constant temperature control device 42, a second reflux device 45 and a pH detection electrode 46, the third constant temperature control device 42 is arranged outside the PN-A reactor 41, the PN-A reactor 41 is provided with an aeration disc and is connected with the second aeration device 44, and the PN-A reactor 41 is also connected with the second dissolved oxygen detection electrode 43, the pH detection electrode 46 and the second reflux device 45;

[0093] The multi-source organic solid waste anaerobic digestion biogas liquid efficient deep denitrification system is also provided with an automatic control device 5, and the automatic control device 5 is connected with the first aeration device 24, the second aeration device 44, the first dissolved oxygen detection electrode 23, the second dissolved oxygen detection electrode 43, the pH detection electrode 46 and a pH automatic adjusting device 6;

[0094] The automatic control device 5 adopts a negative feedback logic control; the first dissolved oxygen detection electrode 23, the second dissolved oxygen detection electrode 43 and the pH detection electrode 46 detect actual values and return to the automatic control device 5. The automatic control device 5 controls the working frequency of the first aeration device 24, the second aeration device 44 and the pH automatic adjusting device 6 according to the negative feedback adjusting logic to stabilize the dissolved oxygen and the pH of the system in a required range. The critical value of the automatic control device 5 is set according to the required conditions of the controlled system.

[0095] The multi-source organic solid waste anaerobic digestion biogas liquid enters the anaerobic reactor 11 through the inlet of the anaerobic reactor 11, and the outlet of the anaerobic reactor 11 is connected to the inlet of the aerobic reactor 21; the outlet of the aerobic reactor 21 is connected to the inlet of the full-automatic coagulation device 31, and the outlet of the aerobic reactor 21 is also connected to the inlet of the anaerobic reactor 11 through the first reflux device 25; the outlet of the full-automatic coagulation device 31 is connected to the inlet of the centrifugal separation device 32, the outlet of the centrifugal separation device 32 is connected to the inlet of the PN-A reactor 41, the outlet of the PN-A reactor 41 is connected to the water outlet, and the outlet of the PN-A reactor 41 is also connected to the inlet of the anaerobic reactor 11 through the second reflux device 45.

[0096] Example 2

[0097] The embodiment provides a multi-source organic solid waste anaerobic digestion biogas liquid efficient deep denitrification process.

[0098] As shown in Figure 2 , a multi-source organic solid waste anaerobic digestion biogas liquid efficient deep denitrification process comprises the following steps:

[0099] (1) The multi-source organic solid waste anaerobic digestion biogas liquid to be treated first enters the anaerobic treatment unit 1 to perform a denitrification process;

[0100] (2) The effluent of the anaerobic treatment unit 1 in step (1) flows into the aerobic treatment unit 2 to remove residual organic matter and part of suspended solids;

[0101] (3) The effluent of the aerobic treatment unit 2 in step (2) enters the suspended matter treatment unit 3 to perform chemical conditioning and centrifugal separation to strengthen the removal of suspended solids, and part of the effluent is refluxed to the anaerobic treatment unit 1;

[0102] (4) The effluent of the suspended matter treatment unit 3 in step (3) enters the PN-A treatment unit 4 to perform a short-cut nitrification-anammox process to strengthen the removal of ammonia nitrogen, part of the effluent is refluxed to the anaerobic treatment unit 1 to further strengthen the removal of nitrate nitrogen, and part of the effluent is directly discharged.

[0103] The multi-source organic solid waste anaerobic digestion biogas liquid to be treated first sequentially passes through the anaerobic treatment unit 1 and the aerobic treatment unit 2; then part of the effluent is refluxed to the anaerobic treatment unit 1, and another part of the effluent sequentially passes through the suspended matter treatment unit 3 and the PN-A treatment unit 4 for corresponding treatment; since the anammox process produces a certain proportion of nitrate nitrogen while denitrifying, part of the effluent of the PN-A treatment unit 4 is refluxed to the anaerobic unit to participate in the reaction again, thereby strengthening the denitrification effect.

[0104] The influent of the multi-source organic solid waste to be treated and the two reflux liquids of the anaerobic digestion biogas slurry are introduced into the anaerobic treatment unit 1 from the bottom, and the effluent is overflowed from the top; the new type of light autotrophic filler (light sponge loaded with sulfur and siderite) is hung in the anaerobic reactor 11, which is used to strengthen the growth of microorganisms and provide electron donor substances for autotrophic denitrification, and the filler density is 0.2 g / cm 3 , and the filling rate is 40%. The dissolved oxygen in the anaerobic reactor 11 is 0.01-0.20 mg / L, the pH is 7.0-8.0, and the temperature is 20-30℃.

[0105] The aerobic treatment unit 2 is operated in an upflow mode; the aeration disc is arranged at the bottom of the reaction zone of the aerobic reactor 21, and the automatic control device 5 is used to control the dissolved oxygen concentration in the reaction zone to be 0.8 mg / L-2.0 mg / L; the pH is controlled to be 8.0-8.5, and the temperature is 30-35℃; and the sludge concentration in the reaction zone is controlled to be 2500-3500 mg / L. In addition, part of the effluent of this unit is refluxed to the anaerobic treatment unit 1, and the reflux flow rate accounts for 50% of the total effluent flow rate, so as to strengthen the removal of organic matter and suspended solids in the wastewater.

[0106] In the suspended solids treatment unit 3, the new type of inorganic conditioner is added to improve the solid-liquid separation effect of the wastewater, and then the suspended solids in the wastewater are removed by centrifugal separation, so that the SS of the wastewater entering the PN-A treatment unit 4 is controlled to be less than 1000 mg / L. At the same time, the chemical conditioning process also has the function of killing microorganisms in the wastewater, so as to avoid the interference of complex bacterial flora on the stable operation of the subsequent PN-A treatment unit 4.

[0107] The PN-A treatment unit 4 adopts the short-cut nitrification-anammox granular sludge process and is operated in an upflow mode; 0.2-0.3 g / L of composite magnesium salt agent is regularly added to maintain the stability and growth of the granular sludge. In addition, the aeration disc is arranged in the PN-A reactor 41, and the automatic control device 5 is used to control the dissolved oxygen concentration in the reaction zone to be 0.1 mg / L-0.3 mg / L; and the pH of the reaction zone of the PN-A reactor 41 is controlled to be 8.0-8.5, and the temperature is 33-35℃. Part of the effluent of the PN-A treatment unit 4 is refluxed to the anaerobic treatment unit 1, and the reflux flow rate is 200%-300% of the influent flow rate of the multi-source organic solid waste anaerobic digestion biogas slurry, so as to remove the residual nitrate nitrogen in the wastewater and realize the advanced denitrification of the wastewater.

[0108] The water quality changes of the multi-source organic solid waste anaerobic digestion biogas slurry before and after treatment are shown in Figure 3 .

[0109] Example 3

[0110] The embodiment provides a multi-source organic solid waste anaerobic digestion biogas slurry efficient and advanced denitrification process.

[0111] The process flow is the same as that of Example 2. Among them, the process devices and operating parameters of the anaerobic treatment unit 1, the aerobic treatment unit 2, and the suspended solids treatment unit 3 are the same as those of Example 2.

[0112] The difference is that the PN-A treatment unit 4 adopts a high-concentration powder carrier-particle sludge mixing technology and is operated in an upflow mode. A new type of silicon-based powder carrier is added in the reaction zone of the PN-A reactor 41, which functions to provide a core for the formation of granular sludge and maintain a high sludge concentration (more than 10,000 mg / L) to improve treatment efficiency. Aeration discs are arranged in the PN-A reactor 41, and the dissolved oxygen concentration in the reaction zone is controlled by the automatic control device 5 to be 0.1-0.3 mg / L; the pH of the reaction zone is controlled to be 8.0-8.5, and the temperature is controlled to be 33-35℃. The effluent from the reaction zone enters the sedimentation tank for sludge-water separation and sludge backflow to recover the powder carrier lost from the reaction zone. The effluent from the PN-A treatment unit 4 is partially backflowed to the anaerobic treatment unit 1, and the backflow rate is 200%-300% of the influent flow rate of the multi-source organic solid waste to be treated in cooperation with the anaerobic digestion effluent, with the purpose of removing residual nitrate nitrogen in the wastewater and achieving deep denitrification of the wastewater.

[0113] The above description of the examples is for the purpose of facilitating the understanding and use of the invention by those of ordinary skill in the art. Those skilled in the art can easily make various modifications to these examples and apply the general principles described herein to other examples without having to undergo creative labor. Therefore, the present invention is not limited to the above examples, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A multi-source organic solid waste and anaerobic digestion effluent efficient deep denitrification process, using a multi-source organic solid waste and anaerobic digestion effluent efficient deep denitrification system, characterized in that, The system for efficient and deep denitrification of the multi-source organic solid waste and anaerobic digestion biogas liquid includes an anaerobic treatment unit, an aerobic treatment unit, a suspended substance treatment unit and a PN-A treatment unit. The anaerobic treatment unit includes an anaerobic reactor and a first constant temperature control device, and the first constant temperature control device is arranged outside the anaerobic reactor. The aerobic treatment unit includes an aerobic reactor, a first aeration device, a first dissolved oxygen detection electrode, a second constant temperature control device and a first reflux device, the second constant temperature control device is arranged outside the aerobic reactor, and the aerobic reactor is connected with the first aeration device, the first dissolved oxygen detection electrode and the first reflux device. The suspended substance treatment unit includes a full-automatic coagulation device and a centrifugal separation device. The full-automatic coagulation device is connected with the centrifugal separation device. The PN-A treatment unit includes a PN-A reactor, a second aeration device, a second dissolved oxygen detection electrode, a third constant temperature control device, a second reflux device and a pH detection electrode, the third constant temperature control device is arranged outside the PN-A reactor, and the PN-A reactor is connected with the second aeration device, the second dissolved oxygen detection electrode, the pH detection electrode and the second reflux device. The multi-source organic solid waste and anaerobic digestion biogas liquid enters the anaerobic reactor through an inlet of the anaerobic reactor, and an outlet of the anaerobic reactor is connected with an inlet of the aerobic reactor. An outlet of the aerobic reactor is connected with an inlet of the full-automatic coagulation device, and the outlet of the aerobic reactor is also connected with the inlet of the anaerobic reactor through the first reflux device. An outlet of the full-automatic coagulation device is connected with an inlet of the centrifugal separation device, an outlet of the centrifugal separation device is connected with an inlet of the PN-A reactor, an outlet of the PN-A reactor is connected with a water outlet, and the outlet of the PN-A reactor is also connected with the inlet of the anaerobic reactor through the second reflux device. The anaerobic reactor is provided with light autotrophic filler, and the light autotrophic filler is loaded with one or more of sulfur-based materials or iron-based materials. The process for efficient and deep denitrification of the multi-source organic solid waste and anaerobic digestion biogas liquid includes the following steps: (1) The multi-source organic solid waste and anaerobic digestion biogas liquid to be treated firstly enters the anaerobic treatment unit to perform a denitrification process; (2) The effluent of the anaerobic treatment unit flows into the aerobic treatment unit to remove residual organic matter and part of suspended solids; (3) Part of the effluent of the aerobic treatment unit is introduced into the suspended substance treatment unit to perform chemical conditioning and centrifugal separation to strengthen the removal of suspended solids, and the other part of the effluent is refluxed to the anaerobic treatment unit; (4) The effluent of the suspended substance treatment unit enters the PN-A treatment unit to perform a short-cut nitrification-anammox process to strengthen the removal of ammonia nitrogen, part of the effluent is refluxed to the anaerobic treatment unit to further strengthen the removal of nitrate nitrogen, and the remaining part is directly discharged; The COD of the multi-source organic solid waste and anaerobic digestion biogas liquid is 7000-10000 mg / L, the ammonia nitrogen content is 1500-2500 mg / L, the total nitrogen content is 4000-6000 mg / L, and the C / N is less than 2. In the anaerobic reactor, the dissolved oxygen concentration is 0.01-0.20 mg / L, the pH is 7.0-8.0, and the temperature is 20-30℃. In the aerobic reactor, the dissolved oxygen concentration is 0.8-2.0 mg / L, the pH is 8.0-8.5, and the temperature is 30-35℃; The centrifugal separation device has a water suspension solid content of less than 1000 mg / L; In the PN-A reactor, the dissolved oxygen concentration is 0.2-0.8 mg / L, the pH is 8.0-8.5, and the temperature is 33-35℃; In step (3), the reflux flow rate of the reflux water from the aerobic treatment unit to the anaerobic treatment unit accounts for 60-80% of the total flow rate of the effluent from the aerobic treatment unit; In step (4), the reflux flow rate of the reflux water from the PN-A treatment unit to the anaerobic treatment unit is 200-300% of the flow rate of the multi-source organic solid waste and the anaerobic digestion liquid.

2. The process according to claim 1, characterized in that, The multi-source organic solid waste and the anaerobic digestion liquid are produced by mixing two or three of kitchen waste, kitchen garbage, or residual sludge and treating them by an anaerobic digestion system.

3. The process according to claim 1, characterized in that, The light autotrophic filler is selected from one or more of light sponge, fluffy fiber ball, or EPS foamed plastic; The density of the light autotrophic filler is 0.1-0.3 g / cm 3 , and the filling rate is 30-50%.

4. The process according to claim 3, characterized in that, The sulfur-based material is selected from one or more of sulfur, pyrite, and sphalerite; The iron-based material is selected from one or more of siderite, reduced iron powder, and iron shavings.

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