Carbon fiber production wastewater treatment device

Abstract

The utility model belongs to the technical field of sewage treatment, and particularly relates to a carbon fiber production wastewater treatment device. Comprising a plate heat exchanger, a polymer sedimentation tank, an air flotation machine, a hydrolysis acidification tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank which are sequentially connected, an inlet of the plate heat exchanger is connected with a carbon fiber production device, and an outlet of the secondary sedimentation tank is connected to a sewage treatment plant; the system further comprises a decyanation pool, an inlet of the decyanation pool is connected with the high-concentration cyano compound wastewater collecting tank, and an outlet of the decyanation pool is connected to the hydrolysis acidification pool; an inlet of the neutralization tank is connected with the acrylic acid production device, and an outlet of the neutralization tank is connected to the hydrolysis acidification tank. By using the acrylic acid production wastewater as the composite carbon source and recovering the dry powder, the outsourcing cost of the carbon source and the sludge treatment cost are remarkably reduced; by combining the synergistic effect of physical pretreatment, chemical decyanation and biodegradation processes, cyanides, suspended solids and organic pollutants are efficiently removed, and it is ensured that the effluent index stably reaches the standard.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and particularly relates to a wastewater treatment device for carbon fiber production. Background Art

[0002] The wastewater generated during the production of carbon fiber, due to its characteristics of high cyanide group and high organic nitrogen, has become a difficult point in the field of industrial wastewater treatment. Such wastewater contains a large amount of suspended solids, toxic cyanides, and refractory organic substances. Traditional treatment processes often face the dual challenges of low efficiency and high cost. Conventional biological treatment systems are difficult to effectively degrade cyanide compounds due to insufficient tolerance of bacteria species, resulting in key indicators such as ammonia nitrogen and total nitrogen in the effluent being difficult to meet the standards. Although chemical cyanide removal can reduce toxicity, it requires a large amount of chemicals and is prone to secondary pollution. At the same time, the high yield of surplus sludge further increases the sludge treatment cost. In addition, the carbon source supplementation in traditional processes relies on purchased chemicals, which not only has a high cost but also increases the environmental burden. In the prior art, the single application of physical, chemical, and biological processes is difficult to achieve efficient coordination, resulting in unstable treatment effects and difficult to meet the requirements of the carbon fiber industry for low-cost and low-pollution wastewater treatment. Therefore, there is an urgent need for an integrated process to solve problems such as the removal of cyanide compounds, the optimization of carbon, nitrogen, and phosphorus balance, and sludge reduction through multi-technology coupling. Summary of the Utility Model

[0003] According to the deficiencies in the above prior art, the purpose of the present utility model is to provide a wastewater treatment device for carbon fiber production, which significantly reduces the cost of purchased carbon source and sludge treatment cost by using acrylic acid production wastewater as a composite carbon source and recovering dry powder; combines the synergistic effects of physical pretreatment, chemical cyanide removal, and biological degradation processes to efficiently remove cyanides, suspended solids, and organic pollutants, ensuring that indicators such as COD, ammonia nitrogen, and total nitrogen in the effluent meet the standards stably.

[0004] The present utility model is implemented by adopting the following technical solutions:

[0005] The wastewater treatment device for carbon fiber production includes a plate heat exchanger, a polymer sedimentation tank, a flotation machine, a hydrolysis acidification tank, an anoxic tank, an aerobic tank, and a secondary sedimentation tank connected in sequence. The inlet of the plate heat exchanger is connected to the drainage outlet of the carbon fiber production device through a pipeline, and the outlet of the secondary sedimentation tank is connected to the sewage treatment plant through a pipeline;

[0006] The sludge outlet of the secondary sedimentation tank is connected to the inlet of the aerobic tank through a first reflux pipeline; the reflux outlet of the aerobic tank is connected to the inlet of the anoxic tank through a second reflux pipeline; the sludge outlet of the anoxic tank is connected to the inlet of the hydrolysis acidification tank through a third reflux pipeline;

[0007] It further includes a cyanide removal tank. The inlet of the cyanide removal tank is connected to a high-concentration cyanide compound wastewater collection tank through a pipeline, and the outlet of the cyanide removal tank is connected to the inlet of the hydrolysis acidification tank through a pipeline;

[0008] It also includes a neutralization tank. The inlet of the neutralization tank is connected to the drainage outlet of the acrylic acid production device through a pipeline, and the outlet of the neutralization tank is connected to the inlet of the hydrolysis acidification tank through a pipeline.

[0009] The sludge discharge port of the polymer sedimentation tank is connected to a centrifuge through a pipeline, and the solid phase outlet of the centrifuge is connected to a dry powder recovery tank through a pipeline.

[0010] Aeration devices are provided in the hydrolysis acidification tank, anoxic tank, aerobic tank, de cyanidation tank and neutralization tank.

[0011] pH on-line monitoring devices are provided in the de cyanidation tank and the neutralization tank.

[0012] An acid adding pipeline, an alkali adding pipeline and an oxidant adding pipeline are respectively connected to the de cyanidation tank.

[0013] An alkali adding pipeline is connected to the neutralization tank.

[0014] The working principle of the carbon fiber production wastewater treatment device is as follows:

[0015] The wastewater generated by the carbon fiber production device first enters a plate heat exchanger and is cooled to an appropriate temperature by circulating cooling water, and then flows into a polymer sedimentation tank. The inclined tube structure in the tank effectively enhances the sedimentation efficiency, and the bottom conical design is convenient for collecting dry powder. These dry powders are dehydrated by a centrifuge and then sent to a dry powder recovery tank for recycling. The wastewater then enters a flotation machine to further remove residual suspended solids. The flotation machine serves as a "firewall" under abnormal conditions to ensure the stable operation of the subsequent treatment process.

[0016] During the carbon fiber production process, if abnormal conditions occur and the cyanide in the wastewater exceeds the standard, the wastewater will be collected in a high-concentration cyanide compound wastewater collection tank and then transported to a de cyanidation tank. In the de cyanidation tank, the wastewater is detoxified by adding acid, alkali and oxidant and combining physical and chemical treatment methods such as aeration. When the pH on-line monitoring device detects that the pH value of the wastewater reaches the standard, the wastewater is fed into the hydrolysis acidification tank in a continuous small flow rate.

[0017] On the other hand, the wastewater generated by the acrylic acid production device first enters the neutralization tank for pH adjustment, and then is supplemented to the hydrolysis acidification tank as a composite carbon source. This measure not only balances the carbon-nitrogen-phosphorus ratio in the hydrolysis acidification tank, but also enhances the denitrification effect, which helps the smooth progress of the subsequent biological treatment process.

[0018] After the wastewater enters the hydrolysis acidification tank, through the way of timed automatic aeration, it promotes the ring opening and chain breaking of macromolecular organic matter and converts organic nitrogen into ammonia nitrogen. At the same time, this aeration method also helps to inhibit the generation of hydrogen sulfide, thus reducing the odor. The treated wastewater flows out from the outlet of the hydrolysis acidification tank and enters the anoxic tank. In the anoxic tank, an anoxic environment is maintained. Using the reflux nitrified liquid (rich in nitrates) from the aerobic tank and the composite carbon source provided by the hydrolysis acidification tank, through the action of denitrifying bacteria, the nitrates are reduced to nitrogen gas to achieve the denitrification goal. The anoxic tank also adopts the way of timed automatic aeration to avoid sludge deposition caused by local anaerobiosis and further reduce the odor. The effluent from the anoxic tank then enters the aerobic tank. The aerobic tank is filled with biological fillers to immobilize nitrifying bacteria. Through continuous aeration, sufficient dissolved oxygen is provided to efficiently oxidize ammonia nitrogen into nitrates. The tank volume design of the aerobic tank meets the reproduction cycle requirements of nitrifying bacteria, and the residual sludge volume is effectively reduced by controlling the plug flow time.

[0019] The effluent from the aerobic tank enters the secondary sedimentation tank for solid-liquid separation. The sludge generated by the secondary sedimentation tank is refluxed to the inlet of the aerobic tank to prevent the loss of nitrifying bacteria; the nitrified liquid in the aerobic tank is refluxed to the inlet of the anoxic tank to supplement nitrates and strengthen the denitrification process; the sludge generated by the anoxic tank is refluxed to the hydrolysis acidification tank to maintain the activity of the sludge in the hydrolysis acidification tank, so as to effectively cope with the impact of abnormal influent water. The effluent clarified by the secondary sedimentation tank is finally transported to the urban sewage treatment plant through pipelines, completing the whole process of treatment.

[0020] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0021] (1) For the carbon fiber production wastewater treatment device described in the present utility model, by integrating acrylic acid production wastewater as a composite carbon source, it reduces the dependence on externally purchased chemicals and lowers the carbon source supplementation cost; by combining the dry powder recovery and sludge reflux system, it realizes the recycling of materials, significantly reduces the generation of solid waste and the sludge treatment cost;

[0022] (2) For the carbon fiber production wastewater treatment device described in the present utility model, through the synergistic action of physical pretreatment, chemical de-cyanation and biodegradation processes, it effectively removes cyanide, suspended solids and organic pollutants, ensuring that the indexes such as effluent COD, ammonia nitrogen and total nitrogen reach the standards stably. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the carbon fiber production wastewater treatment device described in the present utility model;

[0024] In the figure: 1. Plate heat exchanger; 2. Polymer sedimentation tank; 3. Dissolved air flotation machine; 4. Hydrolysis acidification tank; 5. Anoxic tank; 6. Aerobic tank; 7. Secondary sedimentation tank; 8. Carbon fiber production device; 9. Sewage treatment plant; 10. First reflux pipeline; 11. Second reflux pipeline; 12. Third reflux pipeline; 13. Cyanide removal tank; 14. High-concentration cyanide compound wastewater collection tank; 15. Neutralization tank; 16. Acrylic acid production device; 17. Centrifugal dehydrator; 18. Dry powder recovery tank; 19. Aeration device; 20. pH on-line monitoring device; 21. Acid addition pipeline; 22. Alkali addition pipeline; 23. Oxidant addition pipeline. Detailed implementation manner

[0025] In order to make the purpose and technical solutions of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0026] Embodiment 1

[0027] As Figure 1 shown, the carbon fiber production wastewater treatment device includes a plate heat exchanger 1, a polymer sedimentation tank 2, a dissolved air flotation machine 3, a hydrolysis acidification tank 4, an anoxic tank 5, an aerobic tank 6 and a secondary sedimentation tank 7 connected in sequence. The inlet of the plate heat exchanger 1 is connected to the drainage outlet of the carbon fiber production device 8 through a pipeline, and the outlet of the secondary sedimentation tank 7 is connected to the sewage treatment plant 9 through a pipeline;

[0028] The sludge outlet of the secondary sedimentation tank 7 is connected to the inlet of the aerobic tank 6 through the first reflux pipeline 10; the reflux outlet of the aerobic tank 6 is connected to the inlet of the anoxic tank 5 through the second reflux pipeline 11; the sludge outlet of the anoxic tank 5 is connected to the inlet of the hydrolysis acidification tank 4 through the third reflux pipeline 12;

[0029] It further includes a cyanide removal tank 13. The inlet of the cyanide removal tank 13 is connected to the high-concentration cyanide compound wastewater collection tank 14 through a pipeline, and the outlet of the cyanide removal tank 13 is connected to the inlet of the hydrolysis acidification tank 4 through a pipeline;

[0030] It further includes a neutralization tank 15. The inlet of the neutralization tank 15 is connected to the drainage outlet of the acrylic acid production device 16 through a pipeline, and the outlet of the neutralization tank 15 is connected to the inlet of the hydrolysis acidification tank 4 through a pipeline.

[0031] The sludge discharge port of the polymer sedimentation tank 2 is connected to the centrifugal dehydrator 17 through a pipeline, and the solid phase outlet of the centrifugal dehydrator 17 is connected to the dry powder recovery tank 18 through a pipeline.

[0032] The hydrolysis acidification tank 4, the anoxic tank 5, the aerobic tank 6, the cyanide removal tank 13 and the neutralization tank 15 are all provided with an aeration device 19.

[0033] The cyanide removal tank 13 and the neutralization tank 15 are both provided with a pH on-line monitoring device 20.

[0034] The described cyanide removal pool 13 is respectively connected with an acid addition pipeline 21, an alkali addition pipeline 22 and an oxidant addition pipeline 23.

[0035] The described neutralization pool 15 is connected with an alkali addition pipeline 22.

[0036] During operation, the specific process is as follows:

[0037] The wastewater generated by the carbon fiber production device 8 first enters the plate heat exchanger 1 through a pipeline, and the temperature of the wastewater is adjusted to an appropriate range by using circulating cooling water. The cooled wastewater flows into the polymer sedimentation tank 2. The inclined tube structure arranged in the tank improves the sedimentation efficiency of suspended solids, and the bottom conical design facilitates the collection of the settled dry powder. The dry powder is transported to the centrifuge 17 through the sludge discharge port for dehydration treatment, and the dehydrated dry solid enters the dry powder recovery tank 18 for recycling. The wastewater then enters the air flotation machine 3 to further remove residual suspended solids.

[0038] Under abnormal conditions, the wastewater with excessive cyanide is collected in the high-concentration cyanide compound wastewater collection tank 14 and then enters the cyanide removal pool 13. In the cyanide removal pool 13, the pH of the wastewater is adjusted and an oxidant is added through the acid addition pipeline 21, the alkali addition pipeline 22 and the oxidant addition pipeline 23, and cyanide removal treatment is carried out in combination with the aeration device 19. After the treated wastewater is qualified by the pH on-line monitoring device 20, it is continuously and slowly fed into the hydrolysis acidification pool 4.

[0039] At the same time, the wastewater from the acrylic acid production device 16 enters the neutralization pool 15. After the pH is adjusted through the alkali addition pipeline 22, it is supplemented to the hydrolysis acidification pool 4 as a composite carbon source. The wastewater is treated by the timed automatic aeration device 19 in the hydrolysis acidification pool 4 and then enters the anoxic pool 5. An anoxic environment is maintained in the anoxic pool 5, and the reflux nitrified liquid (rich in nitrates) from the aerobic pool 6 is received. Denitrification and nitrogen removal are carried out in combination with the carbon source provided by the hydrolysis acidification pool 4. The effluent from the anoxic pool 5 enters the aerobic pool 6. Biological fillers are filled in the pool and dissolved oxygen is provided through the continuous aeration device 19 to complete the nitrification process of ammonia nitrogen.

[0040] The effluent from the aerobic pool 6 enters the secondary sedimentation tank 7 for solid-liquid separation. The clarified water after sedimentation is transported to the urban sewage treatment plant 9 through a pipeline. The sludge of the secondary sedimentation tank 7 is refluxed to the inlet of the aerobic pool 6 through the first reflux pipeline 10 to prevent the loss of nitrifying bacteria; the nitrified liquid of the aerobic pool 6 is refluxed to the inlet of the anoxic pool 5 through the second reflux pipeline 11 to supplement the nitrates required for denitrification; the sludge of the anoxic pool 5 is refluxed to the hydrolysis acidification pool 4 through the third reflux pipeline 12 to maintain the sludge activity of the hydrolysis acidification pool 4. The entire system realizes the efficient treatment and resource recycling of wastewater through the coordinated action of multiple devices.

Claims

1. A carbon fiber production wastewater treatment device, characterized in that, The invention comprises a plate heat exchanger (1), a polymer sedimentation tank (2), an air flotation machine (3), a hydrolysis acidification tank (4), an anoxic tank (5), an aerobic tank (6), and a secondary sedimentation tank (7) connected in sequence, wherein the inlet of the plate heat exchanger (1) is connected to the drain outlet of the carbon fiber production device (8) through a pipeline, and the outlet of the secondary sedimentation tank (7) is connected to the sewage treatment plant (9) through a pipeline; The sludge outlet of the secondary sedimentation tank (7) is connected to the inlet of the aerobic tank (6) through a first return pipe (10); the return pipe (11) of the aerobic tank (6) is connected to the inlet of the anoxic tank (5); the sludge outlet of the anoxic tank (5) is connected to the inlet of the hydrolysis acidification tank (4) through a third return pipe (12); It also includes a decyanation tank (13), the inlet of the decyanation tank (13) is connected to the high-concentration cyanide compound wastewater collection tank (14) through a pipeline, and the outlet of the decyanation tank (13) is connected to the inlet of the hydrolysis acidification tank (4) through a pipeline; The invention also includes a neutralization tank (15), the inlet of the neutralization tank (15) is connected to the drain outlet of the acrylic acid production device (16) through a pipeline, and the outlet of the neutralization tank (15) is connected to the inlet of the hydrolysis acidification tank (4) through a pipeline.

2. The carbon fiber production wastewater treatment device according to claim 1, wherein, The mud outlet of the polymer precipitation tank (2) is connected to the centrifugal dehydrator (17) through a pipeline, and the solid phase outlet of the centrifugal dehydrator (17) is connected to the dry powder recovery tank (18) through a pipeline.

3. The carbon fiber production wastewater treatment device according to claim 1, characterized in that: The hydrolysis and acidification tank (4), the anoxic tank (5), the aerobic tank (6), the decyanation tank (13) and the neutralization tank (15) are all provided with an aeration device (19).

4. The carbon fiber production wastewater treatment device according to claim 1, wherein, Both the decyanation tank (13) and the neutralization tank (15) are provided with a pH online monitoring device (20).

5. The carbon fiber production wastewater treatment device according to claim 1, wherein The decyanation tank (13) is respectively connected to an acid addition pipeline (21), an alkali addition pipeline (22) and an oxidant addition pipeline (23).

6. The carbon fiber production wastewater treatment device according to claim 1, characterized in that: The neutralization tank (15) is connected to an alkali adding pipeline (22).

Images