Device for removing formaldehyde from high-concentration formaldehyde wastewater

Abstract

This invention provides a device for removing formaldehyde from high-concentration formaldehyde wastewater, comprising an adjusting dosing tank, a first / second reaction tank, a pH adjustment tank, a coagulation and flocculation tank, a sedimentation tank, and a buffer tank. The outlet of the adjusting dosing tank is connected to the inlet of the first reaction tank, the outlet of the first reaction tank is connected to the inlet of the second reaction tank, the outlet of the second reaction tank is connected to the inlet of the pH adjustment tank, the outlet of the pH adjustment tank is connected to the inlet of the coagulation and flocculation tank, the lower part of the outlet of the coagulation and flocculation tank is connected to the lower part of the inlet of the sedimentation tank, and the upper part of the outlet of the sedimentation tank is connected to the upper part of the inlet of the buffer tank. Using this invention, the wastewater is uniformly dosed with chemicals and the pH value is adjusted by the adjusting dosing tank. After the reaction, the pH is adjusted back to neutral by the pH adjustment tank. Coagulation and flocculants are added centrally to the coagulation and flocculation tanks before sedimentation, achieving efficient removal of formaldehyde from high-concentration formaldehyde wastewater with low treatment costs.

Description

Technical Field

[0001] This utility model relates to the technical field of wastewater treatment devices, specifically to a device for removing formaldehyde from high-concentration formaldehyde wastewater. Background Technology

[0002] Formaldehyde in industrial wastewater can be treated using various methods. One such method is biological treatment, which utilizes specific microorganisms to decompose formaldehyde and other organic substances into water and carbon dioxide. This method is suitable for treating low-concentration formaldehyde wastewater. For example, in 2010, Liu Yan et al. published "Catalytic Conversion-Biodegradation Method for Treating High-Concentration Formaldehyde Wastewater" in the journal *Applied Chemical Engineering*, introducing the biological treatment method. Formaldehyde itself has good biochemical properties; low-concentration formaldehyde can serve as a carbon source for many heterotrophic microorganisms, such as *Methylococcus*, *Halomonas*, *Rhodococcus*, and some yeasts. However, when the formaldehyde concentration exceeds 50 mg / L, formaldehyde inhibits microorganisms. Formaldehyde wastewater exceeding 200 mg / L has an inhibitory and killing effect on various microorganisms and species. Therefore, formaldehyde wastewater with a concentration greater than 200 mg / L cannot be directly treated using biological methods and must undergo pretreatment.

[0003] How to efficiently remove formaldehyde from high-concentration formaldehyde wastewater without producing toxic byproducts that affect the biochemical system, while reducing treatment costs and achieving stable industrial production, is a pressing problem that needs to be solved. Utility Model Content

[0004] To solve at least one of the above technical problems, this utility model provides a device for removing formaldehyde from high-concentration formaldehyde wastewater.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0006] This utility model provides a device for removing formaldehyde from high-concentration formaldehyde wastewater, including an adjustment and dosing tank, a first reaction tank, a second reaction tank, a pH adjustment tank, a coagulation and flocculation tank, a sedimentation tank, and a buffer tank. The outlet side of the adjustment and dosing tank is connected to the inlet side of the first reaction tank, the outlet side of the first reaction tank is connected to the inlet side of the second reaction tank, the outlet side of the second reaction tank is connected to the inlet side of the pH adjustment tank, the outlet side of the pH adjustment tank is connected to the inlet side of the coagulation and flocculation tank, the lower part of the outlet side of the coagulation and flocculation tank is connected to the lower part of the inlet side of the sedimentation tank, and the upper part of the outlet side of the sedimentation tank is connected to the upper part of the inlet side of the buffer tank.

[0007] The beneficial effects of this utility model are:

[0008] This invention employs a chemical dosing tank located at the inlet of the first reaction tank for unified chemical dosing and pH adjustment of the wastewater. This facilitates accurate control of the dosage, achieving an optimal reaction environment and improving reaction efficiency. A second reaction tank is located at the outlet of the first reaction tank, extending the contact time and space, allowing formaldehyde in the wastewater to further contact with the chemicals for a more complete reaction. A pH adjustment tank is located at the outlet of the second reaction tank, facilitating the unified adjustment of the pH of the reacted wastewater back to neutral, improving subsequent sedimentation efficiency. Sequentially arranged coagulation and flocculation tanks and sedimentation tanks allow for the centralized addition of coagulants and flocculants to the wastewater before sedimentation, facilitating accurate control of the dosage and ensuring sufficient sedimentation while reducing treatment costs and avoiding waste caused by excessive coagulant and flocculant use, as well as any impact on subsequent biochemical treatment. A buffer tank stores a certain amount of clean water to balance the asynchronous operation of this device with the downstream biochemical system, enabling coordinated operation between this device and external equipment for stable industrial production.

[0009] In summary, this invention achieves efficient removal of formaldehyde from high-concentration formaldehyde wastewater without producing toxic byproducts that could affect the biochemical system during the treatment process; at the same time, the treatment cost is low, enabling stable industrial production.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, the regulating dosing tank includes a feeding tank and a stabilizing tank. The inlet side of the feeding tank is equipped with a wastewater pipe, a reactant pipe, an acid addition pipe, and an alkali addition pipe. The outlet side of the feeding tank is connected to the inlet side of the stabilizing tank through a gate. The outlet side of the stabilizing tank is connected to the inlet side of the first reaction tank.

[0012] Wastewater can be fed into the feeding tank through the wastewater pipe, and reactants can be added according to the flow rate through the reactant pipe. Acid or alkali solutions can be added through the acid or alkali pipe to adjust the pH value, making dosing convenient. The stabilizing tank buffers the wastewater after dosing, thereby compressing the pH value and other reaction environment, which facilitates accurate control of the dosing amount to achieve the optimal reaction environment and improve reaction efficiency.

[0013] Furthermore, the acid addition pipe is also connected to the pH adjustment tank via an acid addition branch pipe; the alkali addition pipe is also connected to the pH adjustment tank via an alkali addition branch pipe.

[0014] It facilitates the transfer of acid or alkali solutions to a pH adjustment tank to regulate their pH value, and has a compact structure.

[0015] Furthermore, agitators are provided in the feeding tank, stabilization tank, first reaction tank, second reaction tank, pH adjustment tank, and coagulation and flocculation tank.

[0016] This ensures uniform feeding and full reaction, while also preventing premature sedimentation of reaction products and extending the cleaning cycle of each tank.

[0017] Furthermore, a steam coil is provided at the bottom of the first reaction tank. The steam coil has multiple through holes, and one end of the steam coil is connected to a steam inlet pipe, with one end of the steam inlet pipe extending out of the first reaction tank.

[0018] It facilitates heating the first reaction tank to the optimal reaction temperature. The steam heating method provides a fast and uniform heating rate, making it easy to quickly reach the optimal reaction temperature.

[0019] Furthermore, the steam coil is spiral-shaped.

[0020] This improved the heating uniformity of the first reaction tank.

[0021] Furthermore, the first reaction tank has an outlet trough on the upper part of the outlet side, and the second reaction tank has a vertical flow pipe on the inlet side. The upper end of the vertical flow pipe is connected to the outlet trough, and the lower end of the vertical flow pipe is connected to a water distribution pipe. Multiple openings are provided on the side wall of the water distribution pipe. The upper part of the outlet side of the second reaction tank is connected to the inlet side of the pH adjustment tank.

[0022] Water from the outlet of the first reaction tank is led to the bottom of the second reaction tank through a vertical pipe and flows out evenly through a distribution pipe, reducing the impact of the influent to the second reaction tank on the upper liquid. Water in the upper part of the outlet side of the second reaction tank can continue to flow out, thus significantly extending the reaction time of the wastewater in the second reaction tank 3.

[0023] Furthermore, a vertical flow well is provided on the inlet side of the pH adjustment tank. The upper end of the vertical flow well is connected to the upper part of the outlet side of the second reaction tank, and the lower end of the vertical flow well is connected to the lower part of the pH adjustment tank.

[0024] The water flowing out of the second reaction tank is directed to the lower part of the pH adjustment tank through a vertical flow well, which reduces the impact of the influent to the pH adjustment tank on the pH value of the upper part.

[0025] Furthermore, the coagulation and flocculation tank includes a coagulation tank body and a flocculation tank body. The inlet side of the coagulation tank body is connected to the outlet side of the pH adjustment tank through a gate, the outlet side of the coagulation tank body is connected to the inlet side of the flocculation tank body through a gate, and the lower part of the outlet side of the flocculation tank body is connected to the lower part of the inlet side of the sedimentation tank.

[0026] By adding coagulant to the coagulation tank and stirring it evenly, then adding flocculant to the flocculation tank and stirring it evenly, and finally feeding the water with added flocculant into the sedimentation tank, the sedimentation efficiency is improved.

[0027] Furthermore, the settling tank is an inclined plate settling tank.

[0028] It has a compact structure and is easy to clean up sludge. Attached Figure Description

[0029] Figure 1 This is a side view of the present invention.

[0030] Figure 2 This is a top view of the present invention.

[0031] In the accompanying drawings, the technical features represented by each reference numeral are as follows:

[0032] 1-Adjusting dosing tank; 2-First reaction tank; 3-Second reaction tank; 4-pH adjustment tank; 5-Coagulation and flocculation tank; 6-Sedimentation tank; 7-Buffer tank; 8-Clear liquid outlet pipe; 9-Feeding tank; 10-Stabilizing tank; 11-Wastewater pipe; 12-Reactant pipe; 13-Acid addition pipe; 14-Alkali addition pipe; 15-Agitator; 16-Steam coil; 17-Steam inlet pipe; 18-Outlet trough; 19-Vertical flow pipe; 20-Water distribution pipe; 21-Vertical flow well; 22-Coagulation tank; 23-Flocculation tank. Detailed Implementation

[0033] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0034] This utility model refers to Figure 1-2 .

[0035] This utility model provides a device for removing formaldehyde from high-concentration formaldehyde wastewater, including an adjustment and dosing tank 1, a first reaction tank 2, a second reaction tank 3, a pH adjustment tank 4, a coagulation and flocculation tank 5, a sedimentation tank 6, and a buffer tank 7. The outlet side of the adjustment and dosing tank 1 is connected to the inlet side of the first reaction tank 2, the outlet side of the first reaction tank 2 is connected to the inlet side of the second reaction tank 3, the outlet side of the second reaction tank 3 is connected to the inlet side of the pH adjustment tank 4, the outlet side of the pH adjustment tank 4 is connected to the inlet side of the coagulation and flocculation tank 5, the lower part of the outlet side of the coagulation and flocculation tank 5 is connected to the lower part of the inlet side of the sedimentation tank 6, and the upper part of the outlet side of the sedimentation tank 6 is connected to the upper part of the inlet side of the buffer tank 7.

[0036] During operation, high-concentration wastewater containing formaldehyde (approximately 2000 mg / L) first enters from the inlet side of the dosing tank 1. Simultaneously, reactants are added to the dosing tank 1 to adjust the wastewater's pH value. Preferably, calcium hydroxide is used as the reactant, and sodium hydroxide is used to adjust the wastewater's pH to 9-13, which is the optimal reaction environment for the "lime-caustic soda composite condensation reaction." After uniform dosing and reaching the optimal pH environment, the dosed wastewater with a suitable pH value enters the first reaction tank 2 and the second reaction tank 3 sequentially through the outlet side of the dosing tank 1 for reaction, continuing until the formaldehyde concentration reaches the influent conditions of the downstream biological treatment system. After the reaction, the wastewater enters the pH adjustment tank 4 through the outlet of the second reaction tank 3, where the pH value is adjusted to neutral. Preferably, the pH value is adjusted to 6-9 to improve the efficiency of the coagulation and flocculation reaction. After adjustment, the pH-neutral wastewater enters the coagulation and flocculation tank 5 from the outlet of the pH adjustment tank 4. Simultaneously, coagulant and flocculant can be added to the coagulation and flocculation tank 5 and stirred evenly. Preferably, the coagulant is polyaluminum chloride and the flocculant is polyacrylamide. After adding the coagulant and flocculant and stirring evenly, the wastewater enters the settling tank 6 from the outlet of the coagulation and flocculation tank 5. Under the static effect of the settling tank 6, the reaction products in the two reaction tanks fully react with the coagulant and flocculant and settle. After settling, the supernatant from the settling tank 6 enters the buffer tank 7. The supernatant can further settle and stabilize in the buffer tank 7. The outlet side of the buffer tank 7 is equipped with a clear liquid outlet pipe 8, which can be used to guide the supernatant from the buffer tank 7 (i.e., the treated water with low formaldehyde concentration) to the downstream biological system. The sediment accumulates into sludge in the settling tank 6, and after a certain amount has accumulated, it is cleaned up or discharged by opening the sludge discharge port at the bottom of the settling tank 6.

[0037] This invention employs a chemical dosing tank 1 arranged at the inlet side of the first reaction tank 2 for uniformly adding chemicals to the wastewater and adjusting the pH value, facilitating accurate control of the dosage to achieve the optimal reaction environment and improve reaction efficiency. A second reaction tank 3 is arranged at the outlet side of the first reaction tank 2, extending the contact time and space, allowing formaldehyde in the wastewater to further contact with the chemicals, resulting in a more complete reaction. A pH adjustment tank 4 is arranged at the outlet side of the second reaction tank 3, facilitating the uniform adjustment of the pH of the reacted wastewater back to neutral, improving subsequent sedimentation efficiency. A coagulation and flocculation tank 5 and a sedimentation tank 6 are arranged sequentially for the centralized addition of coagulants and flocculants to the wastewater before sedimentation, facilitating accurate control of the amount of coagulants and flocculants added, ensuring sufficient sedimentation while reducing treatment costs, and avoiding waste caused by excessive coagulants and flocculants and their impact on subsequent biochemical treatment. A buffer tank 7 stores a certain amount of clean water to balance the asynchronous operation of this device with the downstream biochemical system, thereby enabling this device to coordinate with external equipment and achieve stable industrial production.

[0038] In summary, this invention achieves efficient removal of formaldehyde from high-concentration formaldehyde wastewater without producing toxic byproducts that could affect the biochemical system during the treatment process; at the same time, the treatment cost is low, enabling stable industrial production.

[0039] Furthermore, the regulating dosing tank 1 includes a feeding tank 9 and a stabilizing tank 10. The inlet side of the feeding tank 9 is provided with a wastewater pipe 11, a reactant pipe 12, an acid addition pipe 13, and an alkali addition pipe 14. The outlet side of the feeding tank 9 is connected to the inlet side of the stabilizing tank 10 through a gate. The outlet side of the stabilizing tank 10 is connected to the inlet side of the first reaction tank 2.

[0040] Preferably, the middle part of the outlet side of the stabilizing tank 10 is connected to the middle part of the inlet side of the first reaction tank 2 through a gate.

[0041] Wastewater can be fed into the feeding tank 9 through the wastewater pipe 11. At the same time, reactants can be added through the reactant pipe 12 according to the flow rate ratio. Acid or alkali solutions can be added through the acid addition pipe 13 or alkali addition pipe 14 to adjust the pH value, making dosing convenient. The stabilizing tank 10 buffers the wastewater after dosing, thereby compressing the reaction environment such as pH value, which facilitates accurate control of the dosing amount to achieve the optimal reaction environment and improve reaction efficiency.

[0042] Furthermore, the acid addition pipe 13 is also connected to the pH adjustment tank 4 via an acid addition branch pipe; the alkali addition pipe 14 is also connected to the pH adjustment tank 4 via an alkali addition branch pipe.

[0043] Preferably, valves are provided on the acid addition branch pipe, the alkali addition branch pipe, the acid addition pipe 13 and the alkali addition pipe 14.

[0044] It facilitates the transfer of acid or alkali solutions to pH adjustment tank 4 to adjust their pH value, and has a compact structure.

[0045] Furthermore, agitators 15 are provided in the feeding tank 9, the stabilization tank 10, the first reaction tank 2, the second reaction tank 3, the pH adjustment tank 4, and the coagulation and flocculation tank 5.

[0046] Preferably, the motor part of the agitator 15 is fixed to the top of the corresponding feeding tank 9, stabilizing tank 10, first reaction tank 2, second reaction tank 3, pH adjustment tank 4 and coagulation flocculation tank 5. The stirring rod of the agitator 15 is connected to the motor, and the stirring rod part extends downward into the corresponding feeding tank 9, stabilizing tank 10, first reaction tank 2, second reaction tank 3, pH adjustment tank 4 and coagulation flocculation tank 5.

[0047] This ensures uniform feeding and full reaction, while also preventing premature sedimentation of reaction products and extending the cleaning cycle of each tank.

[0048] Furthermore, a steam coil 16 is provided at the bottom of the first reaction tank 2. The steam coil 16 has multiple through holes. One end of the steam coil 16 is connected to a steam inlet pipe 17, and one end of the steam inlet pipe 17 extends out of the first reaction tank 2.

[0049] It is convenient to heat the first reaction tank 2 to the optimal reaction temperature. The heating is carried out by steam, which has a fast heating rate and uniform heating, making it easy to quickly reach the optimal reaction temperature.

[0050] Furthermore, the steam coil 16 is spiral-shaped.

[0051] This improved the heating uniformity of the first reaction tank 2.

[0052] Furthermore, the first reaction tank 2 has an outlet trough 18 on the upper part of the outlet side, and the second reaction tank 3 has a vertical flow pipe 19 on the inlet side. The upper end of the vertical flow pipe 19 is connected to the outlet trough 18, and the lower end of the vertical flow pipe 19 is connected to a water distribution pipe 20. Multiple openings are provided on the side wall of the water distribution pipe 20. The upper part of the outlet side of the second reaction tank 3 is connected to the inlet side of the pH adjustment tank 4.

[0053] Water from the outlet of the first reaction tank 2 is led to the bottom of the second reaction tank 3 through the vertical flow pipe 19 and flows out evenly through the water distribution pipe 20, which reduces the impact of the water entering the second reaction tank 3 on its upper liquid. Water in the upper part of the outlet side of the second reaction tank 3 can continue to flow out, which fully prolongs the reaction time of the wastewater in the second reaction tank 3.

[0054] Furthermore, the pH adjustment tank 4 is provided with a vertical flow well 21 at the inlet side. The upper end of the vertical flow well 21 is connected to the upper part of the outlet side of the second reaction tank 3, and the lower end of the vertical flow well 21 is connected to the lower part of the pH adjustment tank 4.

[0055] The water flowing out of the second reaction tank 3 is directed to the lower part of the pH adjustment tank 4 through the vertical flow well 21, thereby reducing the impact of the influent to the pH adjustment tank 4 on the pH value of the upper part.

[0056] Furthermore, the coagulation and flocculation tank 5 includes a coagulation tank body 22 and a flocculation tank body 23. The inlet side of the coagulation tank body 22 is connected to the outlet side of the pH adjustment tank 4 through a gate, and the outlet side of the coagulation tank body 22 is connected to the inlet side of the flocculation tank body 23 through a gate. The lower part of the outlet side of the flocculation tank body 23 is connected to the lower part of the inlet side of the sedimentation tank 6.

[0057] Note: The coagulation tank 22 and the flocculation tank 23 have similar functions. The upper part of the outlet side of the coagulation tank 22 can be connected to the upper part of the inlet side of the flocculation tank 23.

[0058] Preferably, the lower part of the outlet side of the flocculation tank 23 is connected to the lower part of the inlet side of the settling tank 6 through a gate. Both the coagulation tank 22 and the flocculation tank 23 are equipped with agitators 15.

[0059] By adding coagulant to coagulation tank 22 and stirring it evenly, then adding flocculant to flocculation tank 23 and stirring it evenly, the water with added flocculant is then fed into sedimentation tank 6, which improves sedimentation efficiency.

[0060] Furthermore, the settling tank 6 is an inclined plate settling tank.

[0061] It has a compact structure and is easy to clean up sludge.

[0062] In the description of this utility model, it should be understood that if descriptive terms indicating orientation, direction, or positional relationship appear, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., the orientation or positional relationship indicated in this specification is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of understanding this utility model and simplifying the description, and does not indicate or imply that the part, element, or whole referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0063] Furthermore, if sequential descriptive terms such as "first," "second," etc., appear, their purpose in this specification is for ease of understanding or simplification. For example, to distinguish multiple technical features of the same type or function, which must be mentioned separately, this specification may use prefixes or suffixes to differentiate them. Therefore, they should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first," "second," etc., may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0064] In this utility model, if descriptive terms describing structural relationships are used, such as "installation," "connection," "joining," and "fixing," they should be interpreted broadly unless otherwise explicitly specified and limited. For example, "installation," "connection," and "joining" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. "Fixing" can refer to an integral fixation or a detachable fixation using fasteners; it can be a direct fixation or a fixation through an intermediate medium. For those skilled in the art, the specific meaning of the above descriptive terms in this utility model can be understood based on the specific circumstances, the context, and the coherence of the preceding and following text.

[0065] In this utility model, if descriptive terms containing subordinate or connecting meanings appear, such as "above" or "below" the second feature, they should not be interpreted restrictively unless otherwise explicitly specified and limited. For example, "above" or "below" can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. For those skilled in the art, the specific meaning of the above descriptive terms in this utility model can be understood according to the specific circumstances, the context, and the coherence of the preceding and following text.

[0066] Furthermore, "above," "on top of," and "above" the first feature in relation to the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments, examples, and features described in this specification, and such combinations or integrations should all fall within the scope of the present invention.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Variations, modifications, substitutions, and modifications made by those skilled in the art to the above embodiments within the scope of information available through public channels and in conjunction with the technical teachings given in this application are still covered within the protection scope of this application.

Claims

1. A device for removing formaldehyde from high-concentration formaldehyde wastewater, characterized in that: The system includes a chemical dosing tank (1), a first reaction tank (2), a second reaction tank (3), a pH adjustment tank (4), a coagulation and flocculation tank (5), a sedimentation tank (6), and a buffer tank (7). The outlet side of the chemical dosing tank (1) is connected to the inlet side of the first reaction tank (2), the outlet side of the first reaction tank (2) is connected to the inlet side of the second reaction tank (3), the outlet side of the second reaction tank (3) is connected to the inlet side of the pH adjustment tank (4), the outlet side of the pH adjustment tank (4) is connected to the inlet side of the coagulation and flocculation tank (5), the lower part of the outlet side of the coagulation and flocculation tank (5) is connected to the lower part of the inlet side of the sedimentation tank (6), and the upper part of the outlet side of the sedimentation tank (6) is connected to the upper part of the inlet side of the buffer tank (7).

2. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 1, characterized in that: The regulating dosing tank (1) includes a feeding tank (9) and a stabilizing tank (10). The inlet side of the feeding tank (9) is provided with a wastewater pipe (11), a reactant pipe (12), an acid addition pipe (13) and an alkali addition pipe (14). The outlet side of the feeding tank (9) is connected to the inlet side of the stabilizing tank (10) through a gate. The outlet side of the stabilizing tank (10) is connected to the inlet side of the first reaction tank (2).

3. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 2, characterized in that: The acid addition pipe (13) is also connected to the pH adjustment tank (4) through an acid addition branch pipe; the alkali addition pipe (14) is also connected to the pH adjustment tank (4) through an alkali addition branch pipe.

4. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 2, characterized in that: Agitators (15) are provided in the feeding tank (9), the stabilizing tank (10), the first reaction tank (2), the second reaction tank (3), the pH adjustment tank (4), and the coagulation and flocculation tank (5).

5. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 1, characterized in that: The bottom of the first reaction tank (2) is also provided with a steam coil (16), which has multiple through holes. One end of the steam coil (16) is connected to a steam inlet pipe (17), and one end of the steam inlet pipe (17) extends out of the first reaction tank (2).

6. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 5, characterized in that: The steam coil (16) is spiral-shaped.

7. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 1, characterized in that: The first reaction tank (2) has an outlet trough (18) on the upper part of the outlet side, and the second reaction tank (3) has a vertical flow pipe (19) on the inlet side. The upper end of the vertical flow pipe (19) is connected to the outlet trough (18), and the lower end of the vertical flow pipe (19) is connected to a water distribution pipe (20). Multiple openings are provided on the side wall of the water distribution pipe (20). The upper part of the outlet side of the second reaction tank (3) is connected to the inlet side of the pH adjustment tank (4).

8. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 7, characterized in that: The pH adjustment tank (4) is also provided with a vertical flow well (21) at the inlet side. The upper end of the vertical flow well (21) is connected to the upper part of the outlet side of the second reaction tank (3), and the lower end of the vertical flow well (21) is connected to the lower part of the pH adjustment tank (4).

9. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to claim 1, characterized in that: The coagulation and flocculation tank (5) includes a coagulation tank body (22) and a flocculation tank body (23). The inlet side of the coagulation tank body (22) is connected to the outlet side of the pH adjustment tank (4) through a gate. The outlet side of the coagulation tank body (22) is connected to the inlet side of the flocculation tank body (23) through a gate. The lower part of the outlet side of the flocculation tank body (23) is connected to the lower part of the inlet side of the sedimentation tank (6).

10. The apparatus for removing formaldehyde from high-concentration formaldehyde wastewater according to any one of claims 1-9, characterized in that: The settling tank (6) is an inclined plate settling tank.

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