A high-concentration formaldehyde wastewater treatment system

Abstract

The application provides a high-concentration formaldehyde wastewater treatment system, which comprises a homogenizing adjusting tank, one side of the homogenizing adjusting tank is connected with a reinforced biological reaction tank, a biological box is arranged in the reinforced biological reaction tank, a filler layer is arranged outside the biological box, and the filler layer is composed of alternately arranged volcanic rocks and activated carbons; one side of the reinforced biological reaction tank is connected with a sedimentation tank through a pipeline, the other side of the sedimentation tank is connected with an A / O reaction tank through a pipeline, and an aeration device is arranged at the upper portion of the A / O reaction tank. The cooperation of the biological box and the filler layer can effectively enrich formaldehyde-resistant bacteria, the adsorption performance of the volcanic rocks and the activated carbons can provide a good growth environment for the microorganisms, the removal efficiency of the high-concentration formaldehyde is significantly improved, and the operation cost is reduced. The optimization design of the aeration device can ensure the uniform distribution of dissolved oxygen in the A / O reaction tank and improve the denitrification effect.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment, specifically to a high-concentration formaldehyde wastewater treatment system. Background Technology

[0002] With the research and application of new materials, formaldehyde, as an important chemical raw material, has been widely used in various fields such as textiles, fine chemical new material production, preservative solutions, and fermentation preservation. It plays an indispensable role, especially in the wood industry, textiles, and the research and production of fine chemical new materials. However, the high-concentration organic wastewater discharged during related industrial production processes contains large amounts of formaldehyde, which has a strong inhibitory effect on the biochemical treatment of organic wastewater. This can lead to the collapse of the biochemical system, resulting in deterioration of effluent water quality and exceeding standards, seriously threatening ecological and environmental safety.

[0003] Currently, the treatment of formaldehyde-containing wastewater typically involves pretreatment processes to convert formaldehyde into alcohols or sugars to eliminate its biotoxicity, followed by biochemical treatment to meet emission standards. Common pretreatment processes include ozone catalytic oxidation, Fenton catalytic oxidation, wet catalytic oxidation, and thermo-alkali polysaccharide processes. However, these processes have significant drawbacks: catalytic oxidation processes require the addition of large amounts of oxidants to oxidize formaldehyde into alcohols, and obtaining these oxidants not only consumes a large amount of reagents but also incurs high electricity consumption; thermo-alkali polysaccharide processes require heating the wastewater to around 70°C and adding large amounts of lime to convert formaldehyde into hexoses, but this process has high operating costs and is complex to operate. Furthermore, existing technologies generally suffer from low treatment efficiency, high operating costs, and complex equipment maintenance, making it difficult to meet the needs of practical engineering projects for the efficient and economical treatment of high-concentration formaldehyde wastewater.

[0004] Therefore, we have made improvements to this and proposed a high-concentration formaldehyde wastewater treatment system. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a high-concentration formaldehyde wastewater treatment system, which solves the problems mentioned in the background section.

[0006] To achieve the above-mentioned objectives, this utility model provides the following technical solution:

[0007] A high-concentration formaldehyde wastewater treatment system is used to solve the above problems.

[0008] The application is as follows:

[0009] The system includes a homogenization equalization tank, one side of which is connected to an enhanced biological reactor (BBR). The BBR contains a biological chamber, and the outside of the biological chamber is covered with a packing layer composed of alternating volcanic rock and activated carbon. One side of the BBR is connected to a sedimentation tank via a pipe, and the other side of the sedimentation tank is connected to an A / O reactor via a pipe. An aeration device is installed at the top of the A / O reactor, and one side of the A / O reactor is connected to an MBR membrane tank via a pipe. The outlet of the MBR membrane tank is connected to a deep treatment tank via a pipe.

[0010] The bio-box includes a frame, and several partitions are fixedly installed inside the frame. The surface of the partitions has multiple through holes, and ceramic filter elements are embedded inside the through holes. The surface of the ceramic filter elements is coated with a formaldehyde-resistant antibacterial coating.

[0011] As a preferred technical solution of this application, the thickness of the filler layer is 20-30cm, the ratio of volcanic rock to activated carbon is 1:1, and a support mesh is provided at the bottom of the filler layer.

[0012] As a preferred technical solution of this application, the aeration device includes an aeration pipe, and several aeration pipes are provided and evenly distributed at the bottom of the A / O reaction tank. A microporous aeration head is fixedly installed on the upper surface of the aeration pipe, and the pore diameter of the microporous aeration head is 1-2mm.

[0013] As a preferred technical solution of this application, the MBR membrane tank includes membrane modules, and multiple membrane modules are arranged vertically inside the MBR membrane tank. The membrane modules are made of polyvinylidene fluoride and have a filtration pore size of 0.1-0.4μm.

[0014] As a preferred technical solution of this application, the deep treatment tank is provided with a stirring mechanism, which includes a stirring shaft. Several blades are fixedly installed on the surface of the stirring shaft, and the ends of the blades are provided with an arc-shaped bending structure. The upper end of the stirring shaft is fixedly connected to the output end of the drive motor.

[0015] As a preferred technical solution of this application, a dosing device is provided on one side of the deep treatment tank, and the outlet of the dosing device is connected to the interior of the deep treatment tank through a pipe. The dosing device stores an oxidant, which is hydrogen peroxide or ozone solution.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] In the scheme of this application:

[0018] The combined use of the biological tank and the packing layer effectively enriches formaldehyde-resistant bacteria. Utilizing the adsorption properties of volcanic rock and activated carbon, a favorable growth environment for microorganisms is provided, significantly improving the removal efficiency of high-concentration formaldehyde while reducing operating costs. Optimized aeration design ensures uniform dissolved oxygen distribution within the A / O reactor, enhancing denitrification. The membrane modules in the MBR membrane tank are made of polyvinylidene fluoride, offering excellent fouling resistance and filtration precision, ensuring stable effluent quality. The mixing mechanism combined with the dosing device in the advanced treatment tank achieves uniform dispersion of the oxidant, further removing residual formaldehyde and enabling wastewater to meet higher discharge standards. The overall system is highly efficient, economical, and practical. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic cross-sectional view of the enhanced bioreactor of this invention.

[0021] Figure 3 This is a schematic diagram of the internal structure of the A / O reaction tank of this utility model;

[0022] Figure 4 This is a schematic diagram of the internal structure of the MBR membrane tank of this utility model;

[0023] Figure 5 This is a schematic diagram of the internal structure of the deep treatment pool of this utility model.

[0024] The image shows:

[0025] 1. Homogenization tank; 2. Enhanced biological reactor; 3. Biological chamber; 4. Packing layer; 5. Primary sedimentation tank; 6. A / O reactor; 7. Aeration device; 8. MBR membrane tank; 9. Advanced treatment tank; 10. Frame; 11. Baffle; 12. Ceramic filter element; 13. Aeration pipe; 14. Microporous aeration head; 15. Membrane module; 16. Stirring mechanism; 17. Stirring shaft; 18. Impeller; 19. Drive motor; 20. Chemical dosing device. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described examples are only some embodiments of this utility model, and not all embodiments.

[0027] Therefore, the following detailed description of the embodiments of this utility model is not intended to limit the scope of the claimed utility model, but merely to illustrate some embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0028] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] To address the technical problems in the background section, the following high-concentration formaldehyde wastewater treatment system is provided:

[0032] Combination Figure 1 - Figure 5 As shown, the high-concentration formaldehyde wastewater treatment system provided by this utility model includes a homogenization and equalization tank 1, an enhanced biological reactor 2, a primary sedimentation tank 5, an A / O reactor 6, an MBR membrane tank 8, and a deep treatment tank 9. These units are connected sequentially by pipelines to form a complete wastewater treatment process, which can effectively remove pollutants from high-concentration formaldehyde wastewater, enabling the effluent to meet discharge standards or reuse requirements.

[0033] In this application, the high-concentration formaldehyde wastewater to be treated first enters the homogenization and equalization tank 1. The main function of this tank is to balance the water quality and quantity of the wastewater to prevent subsequent treatment units from being affected by fluctuations in the influent. The homogenization and equalization tank 1 is equipped with a stirring device to thoroughly mix the wastewater and ensure uniform distribution of pollutants. After homogenization and equalization, the wastewater is transported through pipelines to the enhanced biological reactor 2. The enhanced biological reactor 2 is one of the core units of the entire system, containing a biological chamber 3 and a packing layer 4. The biological chamber 3 consists of a frame 10 and several partitions 11. Multiple through-holes are formed on the surface of each partition 11, and ceramic filter elements 12 are embedded within these through-holes. The surface of the ceramic filter elements 12 is coated with a formaldehyde-resistant bacteria coating, which can enrich formaldehyde-resistant bacteria and provide them with space for attachment and growth. The packing layer 4 is located outside the biological chamber 3 and consists of alternating layers of volcanic rock and activated carbon, with a thickness of 20-30 cm and a volcanic rock to activated carbon ratio of 1:1. A supporting mesh frame is installed at the bottom of the packing layer 4 to fix the packing and prevent it from sinking. When wastewater flows through the enhanced biological reactor 2, the volcanic rock and activated carbon in the packing layer 4 can adsorb organic matter and formaldehyde molecules in the wastewater, while providing a good growth environment for microorganisms, further improving the degradation efficiency.

[0034] Wastewater treated in enhanced biological reactor 2 enters primary settling tank 5. The main function of primary settling tank 5 is to perform preliminary sedimentation and separation of suspended sludge in the wastewater, reducing the treatment load on subsequent units. The supernatant after sedimentation is transported to A / O reactor 6 via pipeline. A / O reactor 6 is divided into an anoxic zone and an aerobic zone, and its main function is to further purify the wastewater through biological denitrification and organic matter degradation. An aeration device 7 is installed at the top of A / O reactor 6, including multiple aeration pipes 13 and microporous aeration heads 14. The aeration pipes 13 are evenly distributed at the bottom of A / O reactor 6, and the microporous aeration heads 14 have a pore size of 1-2 mm, which can uniformly supply oxygen to the wastewater during operation, ensuring that the dissolved oxygen concentration in the aerobic zone is maintained within a suitable range. In the anoxic zone, by controlling the low dissolved oxygen content, denitrifying bacteria are encouraged to reduce nitrates to nitrogen gas, thereby achieving denitrification. Wastewater treated in A / O reactor 6 then enters MBR membrane tank 8.

[0035] The core component of the MBR membrane tank 8 consists of multiple vertically arranged membrane modules 15. These membrane modules 15 are made of polyvinylidene fluoride (PVDF), which possesses excellent fouling resistance and mechanical strength. Their filtration pore size is 0.1-0.4 μm, effectively removing suspended solids and microorganisms from wastewater and ensuring stable effluent quality. The working principle of the MBR membrane tank 8 is to perform solid-liquid separation of the wastewater through the membrane modules 15, while simultaneously utilizing the biodegradation effect of activated sludge within the tank to further remove residual organic matter and formaldehyde. The wastewater treated by the MBR membrane tank 8 then enters the advanced treatment tank 9.

[0036] The advanced treatment tank 9 is equipped with a stirring mechanism 16 and a dosing device 20. The stirring mechanism 16 includes a stirring shaft 17 and impellers 18. The upper end of the stirring shaft 17 is fixedly connected to the output end of the drive motor 19. The end of the impeller 18 is designed with an arc-shaped bending structure, which can generate a strong turbulence effect during operation, so that the wastewater and oxidant are fully mixed. The outlet of the dosing device 20 is connected to the interior of the advanced treatment tank 9 through a pipe. The device stores oxidants such as hydrogen peroxide or ozone solution. During the operation of the advanced treatment tank 9, the dosing device 20 automatically adds an appropriate amount of oxidant according to the concentration of residual formaldehyde in the wastewater. The stirring mechanism 16 ensures that the oxidant is evenly dispersed and fully contacts the wastewater, thereby further degrading residual formaldehyde molecules and ensuring that the effluent meets higher discharge standards.

[0037] Specifically, the working principle of this solution is as follows:

[0038] The entire system operates as follows: First, high-concentration formaldehyde wastewater enters the equalization and conditioning tank 1 for water quality and quantity balancing. Then, the wastewater flows into the enhanced biological reactor 2, where, under the synergistic effect of the biological tank 3 and the packing layer 4, most of the formaldehyde and organic matter are removed through microbial degradation and adsorption. Next, the wastewater enters the primary sedimentation tank 5 for sludge-water separation, and the supernatant enters the A / O reactor 6, where denitrification and organic matter degradation are achieved through biological reactions under anoxic and aerobic environments. Subsequently, the wastewater enters the MBR membrane tank 8, where the water quality is further purified through the efficient filtration and biodegradation of the membrane module 15. Finally, the wastewater enters the advanced treatment tank 9, where oxidants are added via the dosing device 20, and residual formaldehyde is completely removed under the action of the stirring mechanism 16. The entire system is rationally and compactly designed, with close connections between units, enabling efficient and economical treatment of high-concentration formaldehyde wastewater. It is suitable for high-concentration formaldehyde wastewater treatment scenarios generated in industries such as chemical and pharmaceutical manufacturing.

[0039] The above is the entire working process of the device, and all contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0040] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, the present utility model is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present utility model, and all technical solutions and improvements that do not depart from the spirit and scope of the utility model, are covered within the scope of the claims of the present utility model.

Claims

1. A high-concentration formaldehyde wastewater treatment system, comprising a homogenization and equalization tank (1), characterized in that: One side of the homogenization tank (1) is connected to an enhanced biological reactor (2) via a pipe. The enhanced biological reactor (2) is equipped with a biological tank (3) inside and a packing layer (4) is provided outside the biological tank (3). The packing layer (4) is composed of alternating volcanic rock and activated carbon. One side of the enhanced biological reactor (2) is connected to a sedimentation tank (5) via a pipe. The other side of the sedimentation tank (5) is connected to an A / O reactor (6) via a pipe. An aeration device (7) is provided at the top of the A / O reactor (6). One side of the A / O reactor (6) is connected to an MBR membrane tank (8) via a pipe. The outlet of the MBR membrane tank (8) is connected to a deep treatment tank (9) via a pipe.

2. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: The biological box (3) includes a frame (10), and several partitions (11) are fixedly installed inside the frame (10). The surface of the partitions (11) has multiple through holes, and ceramic filter elements (12) are embedded inside the through holes. The surface of the ceramic filter elements (12) is coated with a formaldehyde-resistant coating.

3. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: The thickness of the filler layer (4) is 20cm to 30cm, and the ratio of volcanic rock to activated carbon is 1:

1. A support mesh is provided at the bottom of the filler layer (4).

4. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: The aeration device (7) includes an aeration pipe (13), and several aeration pipes (13) are provided and evenly distributed at the bottom of the A / O reaction tank (6). A microporous aeration head (14) is fixedly installed on the upper surface of the aeration pipe (13), and the aperture of the microporous aeration head (14) is 1 mm to 2 mm.

5. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: The MBR membrane tank (8) includes membrane modules (15), and multiple membrane modules (15) are provided and arranged vertically inside the MBR membrane tank (8). The membrane modules (15) are made of polyvinylidene fluoride and the filtration pore size of the membrane modules (15) is 0.1μm to 0.4μm.

6. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: The deep treatment tank (9) is equipped with a stirring mechanism (16), and the stirring mechanism (16) includes a stirring shaft (17). Several blades (18) are fixedly installed on the surface of the stirring shaft (17), and the ends of the blades (18) are provided with an arc-shaped bending structure. The upper end of the stirring shaft (17) is fixedly connected to the output end of the drive motor (19).

7. The high-concentration formaldehyde wastewater treatment system according to claim 1, characterized in that: A dosing device (20) is provided on one side of the deep treatment tank (9), and the outlet of the dosing device (20) is connected to the interior of the deep treatment tank (9) through a pipe. The interior of the dosing device (20) stores hydrogen peroxide or ozone solution.

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