Efficient denitrification device for acrylonitrile wastewater treatment

Abstract

The utility model discloses a high-efficiency denitrification device for acrylonitrile wastewater treatment, and aims to overcome the defects that the energy consumption is high and byproducts are difficult to treat in the conventional acrylonitrile wastewater treatment. The device comprises a pretreatment part, a pressurized hydrolysis part, a heat exchange part and a denitrification part which are sequentially connected, the pressurized hydrolysis part comprises a pressurized hydrolysis tank, the heat exchange part is used for carrying out heat exchange on sewage discharged from the pressurized hydrolysis part and sewage to enter the structure, and the denitrification part is used for carrying out short-cut nitrification and denitrification. The biodegradability is improved by utilizing the pressurized hydrolysis part; preheating and cooling are realized through the heat exchange part; heat is fully utilized, and energy waste is reduced; and the integrated nitrification short-cut denitrification does not need an additional carbon source, so that the space is saved.

Description

Technical Field

[0001] The utility model relates to the field of sewage treatment, and more specifically, to a high-efficiency denitrification device for treating acrylonitrile wastewater. Background Art

[0002] Acrylonitrile wastewater contains a large amount of nitrogen compounds, which have poor biodegradability and are even toxic, hindering the normal metabolism of the bacterial community.

[0003] This increases the difficulty of treating acrylonitrile wastewater.

[0004] Existing methods for treating acrylonitrile wastewater include incineration, electrocoagulation, etc. Some of these methods consume a lot of energy, and some will produce solid waste that is difficult to treat.

[0005] This application aims to propose an efficient denitrification device for acrylonitrile wastewater treatment in response to the current situation, which can treat acrylonitrile wastewater at a low cost. Summary of the Invention

[0006] The utility model overcomes the shortcomings of the existing acrylonitrile wastewater treatment, such as high energy consumption and difficulty in treating by-products, and provides an acrylonitrile wastewater treatment and high-efficiency denitrification device, which can achieve high-efficiency and low-cost denitrification.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] An efficient denitrification device for treating acrylonitrile wastewater comprises a pretreatment section, a pressurized hydrolysis section, a heat exchange section and a denitrification section connected in sequence. The pressurized hydrolysis section comprises a pressurized hydrolysis tank. The heat exchange section exchanges heat between sewage discharged from the pressurized hydrolysis section and sewage to be introduced into the aforementioned structure. The denitrification section performs short-cut nitrification and denitrification.

[0009] The pressurized hydrolysis section hydrolyzes chemical substances in wastewater that are difficult to biochemically treat, improving their biodegradability.

[0010] The pressurized hydrolysis section needs to heat and pressurize the sewage. The temperature of the sewage discharged from the pressurized hydrolysis section is relatively high. In order to make full use of it, heat is exchanged with the aforementioned steps through the heat exchange section, thereby cooling the sewage while reusing heat to preheat the sewage in the aforementioned device.

[0011] The temperature of the sewage after cooling meets the requirements of short-range nitrification and denitrification. The use of short-range nitrification and denitrification can shorten the treatment path, reduce the amount of aeration, and make full use of the water temperature.

[0012] The device can be used to carry out denitrification with high efficiency and low cost.

[0013] Preferably, the heat exchange unit performs heat exchange between the wastewater discharged from the pressurized hydrolysis unit and the wastewater to be fed into the pretreatment unit. This structure cools the wastewater discharged from the pressurized hydrolysis unit to prevent the temperature from exceeding a threshold and damaging the treated bacterial colonies in the denitrification unit.

[0014] Preferably, the heat exchange unit performs heat exchange between the sewage discharged from the pressurized hydrolysis unit and the sewage to be fed into the pressurized hydrolysis unit. The structure preheats the sewage entering the pressurized hydrolysis unit, thereby reducing energy consumption.

[0015] Preferably, the heat exchange section is a two-stage heat exchanger, which receives wastewater discharged from the heated hydrolysis section, wastewater to be fed into the pressurized hydrolysis section, and wastewater to be fed into the pretreatment section. The two-stage heat exchanger first performs heat exchange between the wastewater discharged from the heated hydrolysis section and the wastewater to be fed into the pressurized hydrolysis section, and then between the wastewater discharged from the heated hydrolysis section and the wastewater to be fed into the pretreatment section. This two-stage heat exchange not only cools the wastewater entering the denitrification section but also utilizes heat in a cascaded manner, reducing heat consumption in the pressurized hydrolysis section.

[0016] Preferably, the pretreatment section includes a dosing tank and a sedimentation tank, wherein the drugs delivered into the dosing tank include acid, alkali and flocculant. This step improves the efficiency of the pressurized hydrolysis section and the bacterial activity of the subsequent denitrification section.

[0017] Preferably, the pressure hydrolysis unit is a pressure-resistant reactor.

[0018] Preferably, the denitrification unit includes a circulating flow reactor, which is provided with aeration pipes at predetermined positions to form a microaerobic zone and an oxygen-limited zone. The integrated denitrification unit can fully utilize aeration and save space.

[0019] Preferably, a transfer tank is provided between the denitrification section and the heat exchange section, and water is continuously supplied to the transfer tank and the denitrification section via a peristaltic pump.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] (1) Using a pressurized hydrolysis section to improve biodegradability;

[0022] (2) Preheating and cooling are achieved through the heat exchange part. Make full use of heat and reduce energy waste;

[0023] (2) The integrated nitrification and short-range denitrification does not require an additional carbon source, thus saving space. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the utility model;

[0025] In the picture:

[0026] Pretreatment section 1, pressurized hydrolysis section 2, heat exchange section 3, denitrification section 4, dosing tank 11, sedimentation tank 12, transfer tank 5, aeration pipe 41, microaerobic zone 42, oxygen-limited zone 43. DETAILED DESCRIPTION

[0027] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are merely relational words determined for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure, and should not be understood as limitations on the present disclosure.

[0031] In this disclosure, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meaning of these terms in this disclosure based on specific circumstances, and they should not be construed as limiting this disclosure.

[0032] Example:

[0033] An efficient denitrification device for acrylonitrile wastewater treatment, Figure 1As shown, the system comprises a pretreatment section 1, a pressurized hydrolysis section 2, a heat exchange section 3, and a denitrification section 4, connected in sequence. The pressurized hydrolysis section 2 includes a pressurized hydrolysis tank. The heat exchange section 3 exchanges heat between the wastewater exiting the pressurized hydrolysis section 2 and the wastewater entering the aforementioned structure. The denitrification section 4 performs short-cut nitrification and denitrification. The pretreatment section 1 includes a dosing tank 11 and a sedimentation tank 12. The drugs delivered into the dosing tank 11 include acids, bases, and flocculants. This step improves the efficiency of the pressurized hydrolysis section 2 and the subsequent bacterial activity in the denitrification section 4. The pressurized hydrolysis section 2 is a pressure-resistant reactor. The denitrification section 4 includes a circulating flow reactor equipped with aeration pipes 41 at predetermined locations, forming a microaerobic zone 42 and an oxygen-limited zone 43. The integrated denitrification section 4 fully utilizes aeration and saves space. A transfer tank 5 is also provided between the denitrification section 4 and the heat exchange section 3. Water is continuously supplied to the transfer tank 5 and the denitrification section 4 via a peristaltic pump.

[0034] In some embodiments, the heat exchanger 3 performs heat exchange between the wastewater discharged from the pressurized hydrolysis section 2 and the wastewater entering the pretreatment section 1. This structure cools the wastewater discharged from the pressurized hydrolysis section 2, preventing the temperature from exceeding a threshold and damaging the treated bacterial colonies in the denitrification section 4. In other embodiments, the heat exchanger 3 performs heat exchange between the wastewater discharged from the pressurized hydrolysis section 2 and the wastewater entering the pressurized hydrolysis section 2. This structure preheats the wastewater entering the pressurized hydrolysis section 2, reducing energy consumption. In some embodiments, the heat exchanger 3 is a two-stage heat exchanger, which receives wastewater discharged from the pressurized hydrolysis section, wastewater entering the pressurized hydrolysis section 2, and wastewater entering the pretreatment section 1. The two-stage heat exchanger first performs heat exchange between the wastewater discharged from the pressurized hydrolysis section and wastewater entering the pressurized hydrolysis section 2, and then performs heat exchange between the wastewater discharged from the pressurized hydrolysis section and wastewater entering the pretreatment section 1. This two-stage heat exchange not only cools the wastewater entering the denitrification section 4 but also utilizes heat in a cascaded manner, reducing energy consumption in the pressurized hydrolysis section 2.

[0035] The pressurized hydrolysis section 2 hydrolyzes chemical substances in the wastewater that are difficult to be biochemically treated, thereby improving biodegradability.

[0036] The pressurized hydrolysis section 2 needs to heat and pressurize the sewage. The temperature of the sewage discharged from the pressurized hydrolysis section 2 is relatively high. In order to make full use of it, heat is exchanged with the aforementioned steps through the heat exchange section 3, thereby cooling the sewage while reusing heat to preheat the sewage in the aforementioned device.

[0037] The temperature of the sewage after cooling meets the requirements of short-range nitrification and denitrification. The use of short-range nitrification and denitrification can shorten the treatment path, reduce the amount of aeration, and make full use of the water temperature.

[0038] The device can be used to carry out denitrification with high efficiency and low cost.

[0039] The above-described embodiments are only preferred solutions of the present invention and do not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. An efficient denitrification device for treating acrylonitrile wastewater, characterized in that: It includes a pretreatment section, a pressurized hydrolysis section, a heat exchange section and a denitrification section connected in sequence. The pressurized hydrolysis section includes a pressurized hydrolysis tank. The heat exchange section exchanges heat between the sewage discharged from the pressurized hydrolysis section and the sewage to be entered into the pressurized hydrolysis section. The denitrification section performs short-range nitrification and denitrification.

2. A highly efficient denitrification device for treating acrylonitrile wastewater according to claim 1, characterized in that: The heat exchange part performs heat exchange between the sewage discharged from the pressurized hydrolysis part and the sewage to be fed into the pressurized hydrolysis part.

3. A highly efficient denitrification device for treating acrylonitrile wastewater according to claim 1, characterized in that: The heat exchange section is a secondary heat exchanger, which is respectively connected to the sewage discharged from the heating and hydrolysis section, the sewage to be entered into the pressurized hydrolysis section, and the sewage to be entered into the pretreatment section. The secondary heat exchanger first performs heat exchange between the sewage discharged from the heating and hydrolysis section and the sewage to be entered into the pressurized hydrolysis section, and then performs heat exchange between the sewage discharged from the heating and hydrolysis section and the sewage to be entered into the pretreatment section.

4. The high-efficiency denitrification device for treating acrylonitrile wastewater according to any one of claims 1 to 3, characterized in that: The pretreatment section includes a dosing tank and a sedimentation tank. The drugs delivered in the dosing tank include acid, alkali and flocculant.

5. A highly efficient denitrification device for treating acrylonitrile wastewater according to claim 4, characterized in that: The pressure hydrolysis section is a pressure-resistant reactor.

6. A highly efficient denitrification device for treating acrylonitrile wastewater according to claim 4, characterized in that: The denitrification section includes a circulating flow reactor, which is provided with an aeration pipe at a preset position and forms a micro-aerobic zone and an oxygen-limited zone.

7. The high-efficiency denitrification device for treating acrylonitrile wastewater according to claim 4, wherein: A transfer tank is also provided between the denitrification section and the heat exchange section, and water is continuously supplied to the transfer tank and the denitrification section through a peristaltic pump.

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