An anaerobic biological treatment system for high ammonia nitrogen organic wastewater

Abstract

This invention discloses an anaerobic biological treatment system for high-ammonia nitrogen organic wastewater, comprising a dual-internal-circulation anaerobic reactor, an NH3 absorption tower, an induced draft fan, and a biogas pipeline. The biogas produced by the dual-internal-circulation anaerobic reactor is collected through the circulation pipeline and divided into two paths: one path is returned to the dual-internal-circulation anaerobic reactor via the induced draft fan, and the other path flows by gravity through the NH3 absorption tower, yielding ammonium sulfate as a byproduct. The purified and collected biogas can be utilized as a resource. This system features a multi-stage series flow field within the cylindrical reaction zone, with an ideal plug flow pattern, resulting in better liquid-solid mass transfer and higher degradation efficiency of organic matter by anaerobic microorganisms. The system directly utilizes endogenously produced biogas for ammonia stripping through the biogas pipeline, which not only reduces the ammonia-inhibiting toxicity of anaerobic microorganisms but also eliminates the need for traditional air stripping devices, making the system simpler and more effective, especially suitable for anaerobic biological denitrification and carbon removal of high-ammonia nitrogen organic wastewater.

Description

Technical Field

[0001] This invention relates to a biological decarbonization and denitrification reactor for wastewater treatment, and more particularly to an anaerobic biological treatment system for high ammonia nitrogen organic wastewater. Background Technology

[0002] In recent years, with the booming development of industry, the amount of wastewater generated has also been gradually increasing. Statistics show that in 2020, the volume of industrial wastewater increased to 57.136 billion cubic meters, indicating that my country still faces a significant demand for industrial wastewater treatment. However, industrial wastewater discharged from key industries such as chemical, pharmaceutical, leather, printing and dyeing, monosodium glutamate, and papermaking not only has high COD concentrations but also high ammonia nitrogen concentrations. High ammonia nitrogen levels inhibit the activity of anaerobic microorganisms, making it difficult for many anaerobic reactors to operate efficiently and stably, severely affecting COD removal efficiency. Therefore, developing a high-efficiency ammonia nitrogen organic wastewater anaerobic biological treatment system with ammonia nitrogen stripping function is of significant practical importance for the decarbonization and denitrification of industrial wastewater.

[0003] In recent years, there have been several patent applications for anaerobic biological treatment technologies for high-concentration ammonia nitrogen wastewater, such as an anaerobic system and method for treating high-concentration nitrogen wastewater (CN 113582455 A). This technology requires coupling with an electrochemical reactor, resulting in a complex process. Some traditional processes also employ air stripping of high-ammonia nitrogen industrial wastewater before it enters the anaerobic reactor, but this leads to a high oxygen content in the wastewater entering the anaerobic reactor, which also inhibits the activity of anaerobic microorganisms. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an anaerobic biological treatment system for high ammonia nitrogen organic wastewater.

[0005] A biological treatment system for high-ammonia nitrogen organic wastewater includes a dual-internal-circulation anaerobic reactor, an NH3 absorption tower, an induced draft fan, and a biogas pipeline. The dual-internal-circulation anaerobic reactor employs an inner guide tube, which is an inverted cone shape, to achieve localized internal circulation of anaerobic microorganisms and organic matter, forming a vortex flow field and enhancing liquid-solid mass transfer. The reactor body is provided with legs from bottom to top, with the legs connected to the bottom of the water distribution zone's bottom cover. One side of the bottom cover is connected to a wastewater inlet pipe, and the other side to a gas distribution pipe. The upper end of the bottom cover is connected to the lower end of the cylindrical reaction zone. The cylindrical reaction zone contains a first cone and a second... The reactor consists of a cone and a cone-shaped inverted funnel-shaped gas collecting pipe at its lower end. A gas distribution pipe is located at the lower end of the first cone, which is located at the lower end of the second cone. The second cone is located at the lower end of the cone-shaped inverted funnel-shaped gas collecting pipe. The upper end of the cylindrical reactor in the reaction zone is connected to the lower end of the inverted cone, and the upper end of the inverted cone is connected to the lower end of the cylindrical reactor in the separation zone. The cylindrical reactor in the separation zone is internally connected to the upper and middle ends of the cone-shaped inverted funnel-shaped gas collecting pipe, the inverted funnel-shaped three-phase separator, the overflow weir, and the drain pipe. The upper end of the inverted funnel-shaped three-phase separator is connected to the exhaust pipe. The biogas generated by the exhaust pipe is collected through a circulation pipeline and divided into two paths. One path is returned to the gas distribution pipe of the double internal circulation anaerobic reactor by an induced draft fan, and the other path flows by gravity through the NH3 absorption tower.

[0006] The biogas produced by the dual internal circulation anaerobic reactor is collected through a circulation pipeline and divided into two paths. One path is returned to the dual internal circulation anaerobic reactor by an induced draft fan, and the other path flows by gravity through an NH3 absorption tower. The former allows the biogas produced by endogenous biological processes to strip ammonia nitrogen from high-ammonia nitrogen wastewater, reducing the inhibitory effect of high oxygen content in the influent on anaerobic microorganisms caused by traditional air stripping. The latter allows NH3 in the biogas to react with dilute sulfuric acid in the absorption tower to obtain ammonium sulfate as a byproduct. The purified and collected tail gas is discharged from the top of the absorption tower.

[0007] The dual internal circulation anaerobic reactor uses a first cone and a second cone as the inner guide tube. The two cones have the same structure, with the upper diameter d2 / lower diameter d1 both being 0.7-0.8; the diameter d2 / diameter D of the cylinder in the reaction zone is 0.6-0.7, and the cone height is twice the middle diameter. This conical structure facilitates the collection of internal aeration and also helps to reduce the dead zone near the inner guide tube wall.

[0008] The aforementioned dual internal circulation anaerobic reactor uses a first cone and a second cone as dual internal guide tubes. The first cone and the second cone are arranged concentrically with a spacing of 0.4-0.6 times their height.

[0009] The first cone of the dual internal circulation anaerobic reactor is located at the lower end of the second cone, and the second cone is located at the lower end of the inverted funnel gas collecting pipe of the cone. The upper diameter of the inverted funnel gas collecting pipe is d0 / d1=0.3-0.5. The upper end of the reaction zone cylinder is connected to the lower end of the inverted cone, and the upper end of the inverted cone is connected to the lower end of the separation zone cylinder. The separation zone cylinder is internally connected to the upper middle end of the lower end of the inverted funnel gas collecting pipe of the cone, the inverted funnel three-phase separator (the lower diameter of the inverted funnel three-phase separator 10 is D1 / the diameter of the separation zone cylinder is D2=0.4-0.5; the upper diameter of the inverted funnel three-phase separator is D3 / the diameter of the inverted funnel three-phase separator is D1 / D1=0.3-0.5), the overflow weir, and the drain pipe. The upper end of the inverted funnel three-phase separator is connected to the exhaust pipe.

[0010] The beneficial effects of this invention are:

[0011] This system features a multi-stage flow field within the cylindrical reaction zone, with an ideal plug flow pattern, resulting in better liquid-solid mass transfer in the anaerobic reactor and higher degradation efficiency of organic matter by anaerobic microorganisms. Furthermore, the system directly utilizes endogenously produced biogas through a biogas pipeline for ammonia stripping, which not only reduces the ammonia-inhibiting toxicity of anaerobic microorganisms but also eliminates the need for traditional air stripping devices. This simplifies the process, improves efficiency, and makes the system particularly suitable for anaerobic biological denitrification and carbon removal from high-ammonia-nitrogen organic wastewater. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of one structure of the present invention.

[0013] The icons are: reactor support leg 1, bottom end cap of water distribution zone 2, sewage inlet pipe 3, cylinder of reaction zone 4, gas distribution pipe 5, first cone 6, second cone 7, inverted horn gas collection pipe 8, inverted cone 9, inverted horn three-phase separator 10, cylinder of separation zone 11, overflow weir 12, exhaust pipe 13, drainage pipe 14, biogas circulation pipeline 16, and NH3 absorption tower 17. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] like Figure 1As shown, a biological treatment system for high ammonia nitrogen organic wastewater includes a dual internal circulation anaerobic reactor, an NH3 absorption tower 17, an induced draft fan 15, and a biogas circulation pipeline 16. The dual internal circulation anaerobic reactor employs an inner guide tube, which is an inverted cone shape, to achieve local internal circulation of anaerobic microorganisms and organic matter, forming a vortex flow field and enhancing liquid-solid mass transfer. The main body of the dual internal circulation anaerobic reactor is provided with legs 1 from bottom to top. The legs 1 are connected to the bottom of the water distribution zone bottom seal 2. One side of the bottom seal 2 is connected to a sewage inlet pipe 3, and the other side is connected to a gas distribution pipe 5. The upper end of the bottom seal 2 is connected to the lower end of the reaction zone cylinder 4. The reaction zone cylinder 4 contains a first cone 6, a second cone 7, and a... The lower end of the inverted trumpet gas collecting pipe 8 is connected to the lower end of the first cone 6, the lower end of the first cone 6 is connected to the lower end of the second cone 7, and the lower end of the second cone 7 is connected to the lower end of the cone-shaped inverted trumpet gas collecting pipe 8. The upper end of the reaction zone cylinder 4 is connected to the lower end of the inverted cone 9, and the upper end of the inverted cone 9 is connected to the lower end of the separation zone cylinder 11. The separation zone cylinder 11 is connected to the upper middle end of the lower end of the cone-shaped inverted trumpet gas collecting pipe 8, the inverted trumpet three-phase separator 10, the overflow weir 12, and the drain pipe 14. The upper end of the inverted trumpet three-phase separator 10 is connected to the exhaust pipe 13. The biogas generated by the exhaust pipe 13 is collected by the circulation pipe 16 and divided into two paths. One path flows back to the gas distribution pipe 5 of the double internal circulation anaerobic reactor through the induced draft fan 15, and the other path flows by gravity through the NH3 absorption tower 17.

[0016] The biogas produced by the dual internal circulation anaerobic reactor is collected through circulation pipeline 16 and divided into two streams. One stream is returned to the dual internal circulation anaerobic reactor via induced draft fan 15, while the other stream flows by gravity through NH3 absorption tower 17. The former allows the biogas produced by endogenous biological processes to strip ammonia nitrogen from high-ammonia nitrogen wastewater, reducing the inhibitory effect of high oxygen content in the influent on anaerobic microorganisms caused by traditional air stripping. The latter allows NH3 in the biogas to react with dilute sulfuric acid in absorption tower 17 to obtain ammonium sulfate as a byproduct. The purified and collected tail gas is discharged from the top of absorption tower 17. The discharged tail gas contains a large amount of methane, which can be further utilized as a resource.

[0017] The dual internal circulation anaerobic reactor uses a first cone 6 and a second cone 7 as an inner guide tube. The diameter d2 / d1 of the cone structure is about 0.7-0.8; the diameter d2 / D is about 0.6-0.7; and the height of the cone is about twice the middle diameter. This cone structure facilitates the collection of internal aeration and also helps to reduce the dead zone near the wall of the inner guide tube.

[0018] The aforementioned dual internal circulation anaerobic reactor uses a first cone 6 and a second cone 7 as dual internal guide tubes. The first cone 6 and the second cone 7 are arranged concentrically with a spacing of approximately 0.4-0.6 times their height. This structure facilitates dual internal circulation, which is equivalent to increasing the number of reactors in series and creating a flow pattern that tends towards plug flow, thereby improving the mass transfer efficiency between anaerobic microorganisms and organic substrates. This flow pattern is conducive to the formation of functional bacterial communities that produce hydrolysis and acidification, hydrogen and acetic acid, and methanogens, thus achieving regionalization of different functional bacterial communities.

[0019] The first cone 6 of the dual internal circulation anaerobic reactor is located at the lower end of the second cone 7, which is located at the lower end of the cone-shaped inverted funnel gas collecting pipe 8, with a diameter d0 / d1 = 0.3-0.5. The upper end of the reaction zone cylinder 4 is connected to the lower end of the inverted cone 9, and the upper end of the inverted cone 9 is connected to the lower end of the separation zone cylinder 11. The separation zone cylinder 11 is internally connected to the upper middle end of the lower end of the cone-shaped inverted funnel gas collecting pipe 8, the inverted funnel three-phase separator 10 (the lower diameter D1 of the inverted funnel three-phase separator 10 / the diameter D2 of the separation zone cylinder 11 = 0.4-0.5; the upper diameter D3 of the inverted funnel three-phase separator 10 / the diameter D1 = 0.3-0.5), the overflow weir 12, and the drain pipe 14. The upper end of the inverted funnel three-phase separator 10 is connected to the exhaust pipe 13. Its structure is compact and facilitates the stripping of NH3 before microbial degradation, effectively reducing the inhibitory toxicity of NH3.

[0020] The embodiments described above can be further combined or replaced, and these embodiments are merely descriptions of preferred embodiments of the present invention, not limitations on the concept and scope of the present invention. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the inventive concept are all within the protection scope of the present invention. The protection scope of the present invention is given by the appended claims and any equivalents.

Claims

1. A biological treatment system for high ammonia nitrogen organic wastewater, characterized in that: The system includes a dual-internal-circulation anaerobic reactor, an NH3 absorption tower, an induced draft fan, and biogas pipelines. The dual-internal-circulation anaerobic reactor employs an internal guide tube to achieve localized internal circulation of anaerobic microorganisms and organic matter, forming a vortex flow field and enhancing liquid-solid mass transfer. The reactor body is equipped with legs from bottom to top. The upper part of the legs connects to the bottom of the water distribution zone's bottom cap. One side of the bottom cap of the water distribution zone is connected to a sewage inlet pipe, and the other side is connected to a gas distribution pipe. The upper end of the bottom cap of the water distribution zone is connected to the lower end of the cylindrical reaction zone. The cylindrical reaction zone contains a first cone, a second cone, and a cone-shaped inverted funnel-shaped collector. At the lower end of the trachea, the gas distribution pipe is located at the lower end of the first cone, the first cone is located at the lower end of the second cone, and the second cone is located at the lower end of the cone-shaped inverted funnel gas collection pipe. The upper end of the reaction zone cylinder is connected to the lower end of the inverted cone, and the upper end of the inverted cone is connected to the lower end of the separation zone cylinder. The lower middle and upper ends of the cone-shaped inverted funnel gas collection pipe, the inverted funnel three-phase separator, the overflow weir, and the drain pipe are respectively connected to the cylinder of the separation zone. The upper end of the inverted funnel three-phase separator is connected to the exhaust pipe. The biogas generated by the exhaust pipe is collected through the circulation pipeline and divided into two paths. One path flows back to the gas distribution pipe of the double internal circulation anaerobic reactor through the induced draft fan, and the other path flows by gravity through the NH3 absorption tower. The biogas produced by the dual internal circulation anaerobic reactor is collected through circulation pipelines and divided into two paths. The former allows the biogas produced by the endogenous biological source to strip ammonia nitrogen from high ammonia nitrogen wastewater, reducing the inhibitory effect of high oxygen content in the influent on anaerobic microorganisms caused by traditional air stripping. The latter allows NH3 in the biogas to react with dilute sulfuric acid in the absorption tower to obtain ammonium sulfate byproduct. The purified and collected tail gas is discharged from the top of the absorption tower. The dual internal circulation anaerobic reactor uses a first cone and a second cone as the inner guide tube. The two cones have the same structure, and the ratio of the upper diameter d2 to the lower diameter d1 is 0.7-0.

8. The upper diameter d2 / the diameter D of the cylinder in the reaction zone is 0.6-0.7, and the cone height is twice the middle diameter. This cone structure facilitates the collection of internal aeration and also helps to reduce the dead zone near the inner guide tube wall. The aforementioned dual internal circulation anaerobic reactor uses a first cone and a second cone as dual internal guide tubes, with the first cone and the second cone arranged concentrically, and the distance between them being 0.4-0.6 times their height. The first cone of the dual internal circulation anaerobic reactor is located at the lower end of the second cone, and the second cone is located at the lower end of the inverted funnel gas collecting pipe of the cone, and the upper diameter of the inverted funnel gas collecting pipe is d0 / d1=0.3-0.5.

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