System for catalyzing advanced oxidation treatment of ammonia nitrogen in wastewater by using homogeneous catalyst

Abstract

The utility model discloses a system for treating ammonia nitrogen in wastewater by catalyzing advanced oxidation through a homogeneous catalyst. The system comprises a catalytic ozonation reactor and a catalyst recovery system, a high-concentration gas-liquid mixer is arranged in the catalytic ozonation reactor; a gas outlet, a water outlet, a gas-liquid separation baffle and a liquid storage tank are arranged at the top of the catalytic ozonation reactor, and after a treated gas-liquid mixture passes through the gas-liquid separation baffle, liquid flows into the liquid storage tank and is conveyed to a catalyst recovery system through the water outlet; and gas passes through the gas-liquid separation baffle and is discharged from a gas outlet in the top of the catalytic ozonation reactor. The high-concentration gas-liquid mixer is arranged, gas distribution is uniform, the gas-liquid mixing efficiency is improved, and the subsequent ammonia nitrogen efficiency and durability are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a system for treating ammonia nitrogen in wastewater by catalyzing advanced oxidation with a homogeneous catalyst. Background Art

[0002] Ammonia nitrogen (NH4+-N) is one of the common pollutants in wastewater, mainly in the form of ammonium ions (NH4+) and free ammonia (NH3). Ammonia nitrogen has many sources, mainly from industrial, agricultural and municipal wastewater discharge. Ammonia nitrogen reduces the dissolved oxygen in water, causing eutrophication of water bodies and destroying the ecological balance. In addition, ammonia nitrogen in water will be converted into nitrates and nitrites by microbial action, affecting aquatic organisms and human health. Ozone is a strong oxidant composed of three oxygen atoms and is highly active. Its oxidizing property is second only to fluorine, and it has shown excellent performance in various applications.

[0003] Ozone is widely used in drinking water treatment, especially in removing organic matter, odor and color. It can decompose organic matter and microorganisms, ensuring that the water quality meets sanitary standards. In the industrial field, ozone can be used to treat various wastewaters, including petrochemical wastewater, printing and dyeing wastewater and landfill leachate. It effectively degrades organic pollutants and chemical wastes, helping to meet environmental regulations.

[0004] It is generally believed that heterogeneous catalysts containing metal oxides such as Mn3O4, MgO, NiO, Co3O4, CuO, ZnO, Fe2O3, Al2O3 are often used to catalyze the oxidation of ammonia nitrogen by ozone, but the ammonia nitrogen conversion rate and nitrogen selectivity are usually not high, and they cannot be taken into account at the same time. Homogeneous catalysts containing corresponding metal ions can achieve high ammonia nitrogen conversion rate and nitrogen selectivity at the same time, and the catalyst dosage is small, but homogeneous catalysts are very easy to leach and cannot be used for a second time, resulting in excessively high costs. The problem of recycling and reusing catalysts in the HCOP process needs to be solved. Developing membrane components that can recycle metal cations to improve the process is the key to realizing the industrial application of this technology. Utility Model Content

[0005] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and utility model name of this application to avoid blurring the purpose of this section, specification abstract and utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0006] In view of the problems existing in the prior art system for treating ammonia nitrogen in wastewater by advanced oxidation catalyzed by homogeneous catalysts, the present utility model is proposed.

[0007] Therefore, the purpose of the utility model is to provide a system for treating ammonia nitrogen in wastewater by catalyzing advanced oxidation with a homogeneous catalyst, which is provided with a high-concentration gas-liquid mixer, which distributes gas evenly, increases the gas-liquid mixing efficiency, and improves the subsequent ammonia nitrogen efficiency and durability.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions: a system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation using a homogeneous catalyst, comprising a catalytic ozone oxidation reactor and a catalyst recovery system;

[0009] A high-concentration gas-liquid mixer is provided inside the catalytic ozone oxidation reactor;

[0010] The top of the catalytic ozone oxidation reactor is provided with an air outlet, a first water outlet, a gas-liquid separation baffle and a liquid storage tank. After the treated gas-liquid mixture passes through the gas-liquid separation baffle, the liquid flows into the liquid storage tank and is sent to the catalyst recovery system through the water outlet, and the gas passes through the gas-liquid separation baffle and is discharged through the air outlet on the top of the catalytic ozone oxidation reactor;

[0011] An air inlet and a first water inlet are provided on the side wall of the catalytic ozone oxidation reactor, and the ozone and the raw water to be treated are sent to the high-concentration gas-liquid mixer inside the catalytic ozone oxidation reactor through the air inlet and the first water inlet for reaction; a second water inlet is provided on the right side of the catalytic ozone oxidation reactor; a water outlet is also provided on the side wall of the catalytic ozone oxidation reactor, and the treated water is sent to the catalyst recovery system;

[0012] The catalyst recovery system is composed of membrane components and can effectively intercept divalent or higher metal ions and anions to form concentrated water containing catalyst;

[0013] The catalyst concentrated water obtained by the catalyst recovery system is circulated to the catalytic ozone oxidation reactor through the second water inlet by a pump. A second water outlet is provided on the right side of the catalyst recovery system, and the treated low-ammonia nitrogen wastewater is discharged through the second water outlet.

[0014] As a preferred scheme of the system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation using a homogeneous catalyst described in the utility model, the catalytic ozone oxidation reactor 1 has a height-to-diameter ratio H / D of 8 to 10, the middle is the reactor body, the two ends of the reactor are connected by flange sealing, and the connection is padded with sealing rubber rings of corresponding sizes.

[0015] As a preferred scheme of the system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation using a homogeneous catalyst described in the utility model, the catalyst used in the catalytic ozone oxidation reactor 1 is a homogeneous catalyst that is soluble in water and can catalytically oxidize ammonia nitrogen in the wastewater into nitrogen, including sulfates and hydrochlorides whose cations are Co, Mn, Ni, and Fe, and the usage amount is 1g / L.

[0016] As a preferred scheme of the system for treating ammonia nitrogen in wastewater by advanced oxidation catalyzed by homogeneous catalysts described in the utility model, the membrane component is a combination of ultrafiltration membrane and nanofiltration membrane, which can effectively intercept metal ions with a valence of more than two, and pass monovalent ions and water molecules, etc. The pore size of the separation membrane is less than 10 nm, and the ultrafiltration membrane and nanofiltration membrane are made of polyethersulfone.

[0017] As a preferred scheme of the system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation using a homogeneous catalyst described in the utility model, the catalytic ozone oxidation reactor 1 and the catalyst recovery system 2 are suitable for treating wastewater with a COD of less than 100 mg / L and ammonia nitrogen of less than 2000 mg / L. After treatment, the ammonia nitrogen in the wastewater is less than 40 mg / L.

[0018] Beneficial effects of the utility model: The utility model is provided with a high-concentration gas-liquid mixer, which distributes gas evenly, increases the gas-liquid mixing efficiency, improves the subsequent ammonia nitrogen efficiency and durability, and is provided with a guide tube at the lower part of the catalytic ozone oxidation reactor, which can make the gas and liquid in the high-concentration gas-liquid mixer circulate and perform a sufficient mixing reaction during the overflow process. A gas-liquid separation system is provided on the top of the catalytic ozone oxidation reactor, which can effectively separate the tail gas and the treated water. In addition, a membrane assembly is connected to the back of the catalytic ozone oxidation reactor, and the ultrafiltration membrane and nanofiltration membrane made of PES material can effectively intercept divalent or higher metal ions and filter out monovalent ions and other substances, so as to achieve the effect of recycling the catalyst, which can be well used in the treatment of wastewater by homogeneous catalytic ozone oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0020] Figure 1 It is a schematic diagram of the overall structure of the system for treating ammonia nitrogen in wastewater by catalyzing advanced oxidation with a homogeneous catalyst according to the utility model. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0024] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0025] Reference Figure 1 , provides a system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation using a homogeneous catalyst, comprising a catalytic ozone oxidation reactor 1 and a catalyst recovery system 2;

[0026] A high-concentration gas-liquid mixer 1-1 is provided inside the catalytic ozone oxidation reactor 1;

[0027] The top of the catalytic ozone oxidation reactor 1 is provided with an air outlet 1-3, a first water outlet 1-2, a gas-liquid separation baffle and a liquid storage tank. After the treated gas-liquid mixture passes through the gas-liquid separation baffle, the liquid flows into the liquid storage tank and is sent to the catalyst recovery system 2 through the first water outlet 1-2, and the gas passes through the gas-liquid separation baffle and is discharged through the air outlet on the top of the catalytic ozone oxidation reactor;

[0028] Among them, an air inlet 1-4 and a first water inlet 1-5 are provided on the side wall of the catalytic ozone oxidation reactor 1, and ozone and raw water to be treated are sent to the high-concentration gas-liquid mixer 1-1 inside the catalytic ozone oxidation reactor through the air inlet 1-4 and the first water inlet 1-5 for reaction; a second water inlet 2-2 is provided on the right side of the catalytic ozone oxidation reactor 1; a first water outlet 1-2 is also provided on the side wall of the catalytic ozone oxidation reactor 1, and the treated water is sent to the catalyst recovery system 2;

[0029] Among them, the catalyst recovery system 2 is composed of a membrane component and can effectively intercept divalent or higher metal ions and anions to form concentrated water containing catalyst; specifically, the membrane component is a combination of ultrafiltration membrane and nanofiltration membrane, which can effectively intercept divalent or higher metal ions and pass monovalent ions and water molecules, etc. The pore size of the separation membrane is less than 10 nm, and the ultrafiltration membrane and nanofiltration membrane are made of polyethersulfone.

[0030] Among them, the catalyst concentrated water obtained by the catalyst recovery system 2 is circulated to the catalytic ozone oxidation reactor 1 through the second water inlet 2-2 by a pump. A second water outlet 2-1 is provided on the right side of the catalyst recovery system 2, and the treated low-ammonia nitrogen wastewater is discharged through the second water outlet 2-1.

[0031] Among them, the catalytic ozone oxidation reactor 1 has a height-to-diameter ratio H / D of 8 to 10, with the reactor body in the middle. The two ends of the reactor are connected by flange sealing, and the joints are padded with sealing rubber rings of corresponding sizes. The catalyst used in the catalytic ozone oxidation reactor 1 is a homogeneous catalyst that is soluble in water and can catalytically oxidize ammonia nitrogen in wastewater into nitrogen, including sulfates, hydrochlorides or other salts with cations of Co, Mn, Ni, and Fe, and the usage is 1g / L. The catalytic ozone oxidation reactor 1 and the catalyst recovery system 2 are suitable for the treatment of wastewater with COD less than 100 mg / L and ammonia nitrogen less than 2000 mg / L. After treatment, the ammonia nitrogen in the wastewater is less than 40mg / L.

[0032] The utility model is provided with a high-concentration gas-liquid mixer, which distributes gas evenly, increases the gas-liquid mixing efficiency, and improves the subsequent ammonia nitrogen efficiency and durability. A guide tube is provided at the lower part of the catalytic ozone oxidation reactor, which can make the gas and liquid in the high-concentration gas-liquid mixer circulate and perform a sufficient mixing reaction during the overflow process. A gas-liquid separation system is provided on the top of the catalytic ozone oxidation reactor, which can effectively separate the tail gas and the treated water. In addition, a membrane assembly is connected to the rear of the catalytic ozone oxidation reactor, and the ultrafiltration membrane and nanofiltration membrane made of PES material can effectively intercept divalent or higher metal ions and filter out monovalent ions and other substances, so as to achieve the effect of recycling the catalyst, and can be well used in the treatment of wastewater by homogeneous catalytic ozone oxidation method.

[0033] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation with a homogeneous catalyst, characterized in that: It comprises a catalytic ozone oxidation reactor (1) and a catalyst recovery system (2); The catalytic ozone oxidation reactor (1) is provided with a high-concentration gas-liquid mixer (1-1) inside; The catalytic ozone oxidation reactor (1) is provided with an air outlet (1-3), a first water outlet (1-2), a gas-liquid separation baffle and a liquid storage tank at the top; after the treated gas-liquid mixture passes through the gas-liquid separation baffle, the liquid flows into the liquid storage tank and is sent to the catalyst recovery system (2) through the first water outlet (1-2); and the gas passes through the gas-liquid separation baffle and is discharged from the air outlet at the top of the catalytic ozone oxidation reactor; An air inlet (1-4) and a first water inlet (1-5) are provided on the side wall of the catalytic ozone oxidation reactor (1), and the ozone and the raw water to be treated are sent to the high-concentration gas-liquid mixer (1-1) inside the catalytic ozone oxidation reactor via the air inlet (1-4) and the first water inlet (1-5) for reaction; a second water inlet (2-2) is provided on the right side of the catalytic ozone oxidation reactor (1); a first water outlet (1-2) is also provided on the side wall of the catalytic ozone oxidation reactor (1), and the treated water is sent to the catalyst recovery system (2); The catalyst recovery system (2) is composed of a membrane component and can effectively intercept divalent or higher metal ions and anions to form concentrated water containing the catalyst; The catalyst concentrated water obtained by the catalyst recovery system (2) is circulated to the catalytic ozone oxidation reactor (1) by a pump through a second water inlet (2-2). A second water outlet (2-1) is provided on the right side of the catalyst recovery system (2), and the treated low-ammonia nitrogen wastewater is discharged through the second water outlet (2-1).

2. The system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation of homogeneous catalyst according to claim 1, characterized in that: The catalytic ozone oxidation reactor (1) has a height-to-diameter ratio H / D of 8-10, with the reactor body in the middle, and flanges sealingly connected the two ends of the reactor, with sealing rubber rings of corresponding sizes padded at the connection points.

3. The system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation of homogeneous catalyst according to claim 2, characterized in that: The catalyst used in the catalytic ozone oxidation reactor (1) is a homogeneous catalyst that is soluble in water and can catalytically oxidize ammonia nitrogen in wastewater into nitrogen gas, including sulfates and hydrochlorides whose cations are Co, Mn, Ni, and Fe, and the usage amount is 1 g / L.

4. The system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation of homogeneous catalyst according to claim 1, characterized in that: The membrane assembly is a combination of an ultrafiltration membrane and a nanofiltration membrane, which can effectively intercept metal ions with a valence of more than two, while passing monovalent ions and water molecules. The pore size of the separation membrane is less than 10 nm, and the ultrafiltration membrane and the nanofiltration membrane are made of polyethersulfone.

5. The system for treating ammonia nitrogen in wastewater by catalytic advanced oxidation of homogeneous catalyst according to claim 1, characterized in that: The catalytic ozone oxidation reactor (1) and the catalyst recovery system (2) are suitable for treating wastewater with a COD of less than 100 mg / L and an ammonia nitrogen content of less than 2000 mg / L. After treatment, the ammonia nitrogen in the wastewater is less than 40 mg / L.

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