COD (Chemical Oxygen Demand) degradation device for high-concentration coking wastewater

Abstract

The utility model belongs to the technical field of energy conservation and environmental protection, and particularly relates to a high-concentration coking wastewater COD (Chemical Oxygen Demand) degradation device which comprises a reaction tank, a degradation device is arranged in the reaction tank, the degradation device comprises a decyanation unit, a micro-aerobic aeration unit, an oxygenation aeration unit and a precipitation unit, the decyanation unit is arranged in the reaction tank, and the precipitation unit is arranged in the reaction tank. The micro-aerobic aeration unit is mounted on the right side of the reaction tank, the oxygenation aeration unit is mounted on the right side of the reaction tank, and the precipitation unit is mounted on the right side of the reaction tank. According to the high-concentration coking wastewater COD degradation device, a pre-aeration oxidation pond is improved into a combined unit of the decyanation pond, the micro-aerobic aeration pond, the moderate-oxygen aeration pond, the oxygen-enriched adjusting pond and the settling pond, each independent water pond has different functions, various defects of the pre-aeration oxidation pond are perfectly overcome on the basis of stably degrading high-concentration COD according to the functions of different units, and the high-concentration COD degradation efficiency is improved. Meanwhile, the tank capacity of the pre-aeration oxidation tank is greatly reduced, and the investment and operation cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy conservation and environmental protection, in particular to a high-concentration coking wastewater COD degradation device. Background Art

[0002] Coking wastewater is a typical toxic and difficult to degrade organic wastewater. It mainly comes from the initial cooling of coke oven gas and the production water and steam condensation wastewater in the coking production process. It refers to the wastewater generated in the process of coal coking, gas purification, chemical product recovery and chemical product refining. The COD in coking wastewater is mainly composed of organic components, inorganic components and suspended solids. The inorganic components are SCN - , CN - , S 2- 、NO 2- etc.; among them, SCN- is the main component of COD inorganic components, and the organic components are mainly phenolic compounds, heterocyclic compounds, and naphthalene substances; the suspended matter is mainly coal dust, coke dust and water-insoluble oils; in the actual treatment process of coking wastewater, affected by the changes in various external factors such as coking process, coking coal quality, coking time of coke oven, coke production capacity control, and new chemical production process, the actual COD concentration of coking wastewater has increased from the designed 3000-3500 mg / L to 5000-6000 mg / L, and has shown a rising trend. The actual COD concentration of coking wastewater from a few coking enterprises has increased to 8000-9000 mg / L. Such a high concentration of COD influent has caused a serious impact on the existing coking wastewater treatment station, resulting in a large number of deaths of activated sludge in the biochemical system and excessive effluent.

[0003] Existing technology: In order to protect the coking wastewater treatment station from the impact of high-concentration COD in the influent, the existing technology mainly adds pretreatment facilities to reduce the influent COD. The main methods are adding COD degradation agents, adding iron-carbon micro-electrolysis systems for chemical oxidation, and adding pre-aeration oxidation tanks for aeration oxidation. The operating cost of adding COD degradation agents is too high for enterprises to bear. The investment cost of adding iron-carbon micro-electrolysis systems is too high, and the iron-carbon system is seriously blocked. These two treatment methods have been gradually eliminated, and adding pre-aeration oxidation tanks for aeration oxidation has become the existing mainstream technology.

[0004] The core process of the newly added pre-aeration oxidation pond is as follows: after the coking wastewater is treated by oil removal, flotation and other pre-treatment facilities to remove petroleum pollutants in the influent, it enters the pre-aeration oxidation pond, where activated sludge is cultivated. At the same time, the blower is used to aerate the pre-aeration oxidation pond, and part of the high-concentration COD is oxidized by air. Part of it is adsorbed and degraded by the activated sludge, and finally the high-concentration COD is degraded to the design range of the biochemical system of the coking wastewater treatment station and enters the biochemical treatment unit.

[0005] Defects and shortcomings: 1) High-concentration COD coking wastewater contains a large amount of SCN - , CN - , S 2- 1) Toxic pollutants such as cyanide directly enter the pre-aeration tank, which will cause the death of a large number of activated sludge; 2) High-concentration COD coking wastewater contains a large amount of phenolic compounds, which will form a large amount of foam during the oxidation process. After these foams are mixed with dead activated sludge, they are extremely viscous and difficult to break naturally. The foam overflows and pollutes the environment; 3) During the degradation of high-concentration COD in the pre-aeration tank, the COD change gradient is too large (6000mg / l to 3000mg / l), which places extremely high requirements on the design of aeration and oxygenation facilities, and can easily cause local insufficient oxygenation and local excessive aeration; 4) In order to solve the above defects, the design margin of the pre-aeration tank is too high, and the design tank capacity and equipment are too large, resulting in high investment and energy waste.

[0006] Therefore, we proposed a high-concentration coking wastewater COD degradation device to solve the above problems. Utility Model Content

[0007] The utility model aims to provide a high-concentration coking wastewater COD degradation device to solve the problems raised in the above background technology.

[0008] To achieve the above object, the utility model provides the following technical solutions: a high-concentration coking wastewater COD degradation device, comprising a reaction tank, wherein a degradation device is installed inside the reaction tank, wherein the degradation device comprises a decyanation unit, a micro-oxygen aeration unit, an oxygenated aeration unit, and a precipitation unit, wherein the decyanation unit is installed inside the reaction tank, the micro-oxygen aeration unit is installed on the right side of the reaction tank, the oxygenated aeration unit is installed on the right side of the reaction tank, and the precipitation unit is installed on the right side of the reaction tank;

[0009] The decyanation unit comprises a high-concentration coking wastewater COD inlet pipe, a flow meter, a COD online detector, a stirring component, a ferrous sulfate inlet, and a PAM inlet. The high-concentration coking wastewater COD inlet pipe is installed on the left side of the reaction tank, the flow meter is installed on the outer surface of the high-concentration coking wastewater COD inlet pipe, the COD online detector is installed inside the high-concentration coking wastewater COD inlet pipe, the stirring component is installed inside the reaction tank, the ferrous sulfate inlet is installed on the top of the reaction tank, and the PAM inlet 107 is installed on the top of the reaction tank 101. FeSO4 agent and PAM coagulant agent are added to react with SCN in the coking wastewater. - , CN - Reaction, in Fe 2+In the case of excess, water-insoluble Fe4[Fe(CN)6]3 precipitate is generated, thereby achieving the purpose of removing cyanide and reducing the toxicity of the influent. The Fe4[Fe(CN)6]3 precipitate sinks to the bottom of the pool under the action of gravity and is discharged into the sludge pool for filter pressure treatment through the sludge pump.

[0010] Preferably, the microaerobic aeration unit comprises a microaerobic aeration tank, an aeration addition tube, a tubular aerator, and a dissolved oxygen online detector. The microaerobic aeration tank is installed on the right side of the reaction tank, the aeration addition tube is installed on the top of the microaerobic aeration tank, the tubular aerator is installed on the bottom of the aeration addition tube, and the dissolved oxygen online detector is installed inside the microaerobic aeration tank. By installing the microaerobic aeration unit, the microaerobic aeration tank controls the dissolved oxygen in the tank to 0.5-1 mg / L, thereby providing basic oxygen for the activated sludge. At the same time, in order to ensure the removal efficiency of COD, the sludge concentration of the microaerobic aeration tank is increased from 4000 mg / L to 8000 mg / L by controlling the discharge of residual sludge.

[0011] Preferably, the oxygenated aeration unit includes a medium oxygen aeration group and an oxygen-enriched aeration group;

[0012] The medium oxygen aeration group includes a mixed aeration tank, an aeration adding pipe 2, a liftable aerator, and a dissolved oxygen online detector 2. The mixed aeration tank is installed on the right side of the micro-aeration aeration tank, the aeration adding pipe 2 is installed on the top of the mixed aeration tank, the liftable aerator is installed on the bottom of the aeration adding pipe 2, and the dissolved oxygen online detector 2 is installed inside the mixed aeration tank. By installing the medium oxygen aeration group, after being treated by the micro-aeration aeration tank, the COD and phenolic compounds of the influent are significantly reduced, but they do not reach the influent of the subsequent biochemical treatment system. The dissolved oxygen in the medium oxygen aeration tank can be controlled to 1-2 mg / L to further degrade COD. The liftable aerator is used for oxygenation in the medium oxygen aeration tank.

[0013] Preferably, the oxygen-enriched aeration group comprises a baffle, a liftable aerator, an aeration pipe, and a dissolved oxygen detection device. The baffle is installed inside the mixed aeration tank, the liftable aerator is installed inside the mixed aeration tank, the aeration pipe is installed on the top of the liftable aerator, and the dissolved oxygen detection device is installed inside the mixed aeration tank to control the concentration of effluent COD. If the influent COD is too high, after being treated in the micro-oxygen aeration tank and the medium-oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to an oxygen-enriched state to improve the COD treatment efficiency. If the influent COD is low, after being treated in the micro-oxygen aeration tank and the medium-oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to a micro-oxygen state to reduce the COD treatment efficiency, thereby ensuring that the effluent COD of the oxygen-enriched regulating tank meets the influent requirements of the subsequent biochemical treatment system.

[0014] Preferably, the sedimentation unit includes a sedimentation tank, a sludge return pipe, a sludge return pump, and a return pipe. The sedimentation tank is installed on the right side of the reaction tank, the sludge return pipe is installed on the back of the sedimentation tank, the sludge return pump is installed on the back of the sludge return pipe, and the return pipe is installed on the back of the sludge return pump. By installing the sedimentation unit, mud and water separation and residual sludge discharge are performed. After separation, part of the activated sludge is returned to the front aeration tank, and the excess is discharged into the sludge tank for filter press treatment.

[0015] Preferably, an A\O biochemical treatment system is installed on the right side of the sedimentation tank.

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

[0017] 1. The high-concentration coking wastewater COD degradation device, the pre-aeration oxidation tank is improved into a combination unit of decyanation tank + micro-oxygen aeration tank + medium oxygen aeration tank + oxygen-enriched regulating tank + sedimentation tank. Each individual tank has different functions. According to the functions of different units, on the basis of stable degradation of high-concentration COD, it perfectly solves the various defects of the pre-aeration oxidation tank, and at the same time greatly reduces the tank capacity of the pre-aeration oxidation tank, saving investment and operation costs.

[0018] 2. The high-concentration coking wastewater COD degradation device, by refining the specific functions of each treatment unit, greatly improves the stability of the COD removal efficiency of high-concentration coking wastewater, and solves various defects of the existing pre-aeration oxidation tank, greatly reducing the investment cost and operating cost of treating high-concentration coking wastewater COD; BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the overall structure diagram of the utility model;

[0020] Figure 2 It is the internal structure diagram of the utility model;

[0021] Figure 3 This is a structural diagram of the cyanide removal unit of the utility model.

[0022] In the figure: 101, reaction tank; 102, high concentration coking wastewater COD inlet pipe; 103, flow meter; 104, COD online detection 1; 105, stirring assembly; 106, ferrous sulfate addition inlet; 107, PAM addition inlet; 201, micro-oxygen aeration tank; 202, aeration addition pipe 1; 203, tubular aerator; 204, dissolved oxygen online detection 1; 301, medium oxygen aeration tank; 302, aeration addition pipe 2; 303, liftable aerator; 304, dissolved oxygen online detection 2; 401, sedimentation tank; 402, sludge return pipe; 403, sludge return pump; 404, return pipe; 5, A\O biochemical treatment system. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] See also Figure 1-Figure 3 The utility model provides a technical solution: a high-concentration coking wastewater COD degradation device, including a reaction tank 101, a degradation device is installed inside the reaction tank 101, the degradation device includes a decyanation unit, a micro-oxygen aeration unit, an oxygenated aeration unit, and a precipitation unit, the decyanation unit is installed inside the reaction tank 101, the micro-oxygen aeration unit is installed on the right side of the reaction tank 101, the oxygenated aeration unit is installed on the right side of the reaction tank 101, and the precipitation unit is installed on the right side of the reaction tank 101;

[0025] The decyanation unit includes a high-concentration coking wastewater COD inlet pipe 102, a flow meter 103, a COD online detector 104, a stirring component 105, a ferrous sulfate inlet 106, and a PAM inlet 107. The high-concentration coking wastewater COD inlet pipe 102 is installed on the left side of the reaction tank 101, the flow meter 103 is installed on the outer surface of the high-concentration coking wastewater COD inlet pipe 102, the COD online detector 104 is installed inside the high-concentration coking wastewater COD inlet pipe 102, the stirring component 105 is installed inside the reaction tank 101, the ferrous sulfate inlet 106 is installed on the top of the reaction tank 101, and the PAM inlet 107 is installed on the top of the reaction tank 101. FeSO4 agent and PAM coagulant agent are added to react with SCN in the coking wastewater. - , CN - Reaction, in Fe 2+ In the case of excess, water-insoluble Fe4[FeCN6]3 precipitate is generated, thereby achieving the purpose of removing cyanide and reducing the toxicity of the influent. The Fe4[FeCN6]3 precipitate sinks to the bottom of the pool under the action of gravity and is discharged into the sludge pool for filter pressure treatment through the sludge pump.

[0026] The micro-aerobic aeration unit includes a micro-aerobic aeration tank 201, an aeration addition pipe 202, a tubular aerator 203, and a dissolved oxygen online detector 204. The micro-aerobic aeration tank 201 is installed on the right side of the reaction tank 101, the aeration addition pipe 202 is installed on the top of the micro-aerobic aeration tank 201, the tubular aerator 203 is installed on the bottom of the aeration addition pipe 202, and the dissolved oxygen online detector 204 is installed inside the micro-aerobic aeration tank 201. By installing the micro-aerobic aeration unit, the micro-aerobic aeration tank controls the dissolved oxygen in the tank to 0.5-1 mg / L, thereby providing basic oxygen for the activated sludge. At the same time, in order to ensure the removal efficiency of COD, the sludge concentration of the micro-aerobic aeration tank is increased from 4000 mg / L to 8000 mg / L by controlling the discharge of residual sludge.

[0027] The oxygenated aeration unit includes a medium oxygen aeration group and an oxygen-enriched aeration group;

[0028] The medium oxygen aeration group includes a mixed aeration tank 301, an aeration adding pipe 2 302, a liftable aerator 303, and a dissolved oxygen online detector 2 304. The mixed aeration tank 301 is installed on the right side of the micro-aeration aeration tank 201, the aeration adding pipe 2 302 is installed on the top of the mixed aeration tank 301, the liftable aerator 303 is installed on the bottom of the aeration adding pipe 2 302, and the dissolved oxygen online detector 2 304 is installed inside the mixed aeration tank 301. By installing the medium oxygen aeration group, after treatment by the micro-aeration aeration tank, the COD and phenolic compounds of the influent are significantly reduced, but they do not reach the influent of the subsequent biochemical treatment system. The dissolved oxygen in the medium oxygen aeration tank can be controlled to 1-2 mg / L to further degrade COD. The liftable aerator is used for oxygenation in the medium oxygen aeration tank.

[0029] The oxygen-enriched aeration group includes a baffle, a liftable aerator, an aeration pipe, and a dissolved oxygen detection device. The baffle is installed inside the mixed aeration tank 301, the liftable aerator is installed inside the mixed aeration tank 301, the aeration pipe is installed on the top of the liftable aerator, and the dissolved oxygen detection device is installed inside the mixed aeration tank 301 to control the concentration of effluent COD. If the influent COD is too high, after being treated in the micro-oxygen aeration tank and the medium-oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to an oxygen-enriched state to improve the COD treatment efficiency. If the influent COD is low, after being treated in the micro-oxygen aeration tank and the medium-oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to a micro-oxygen state to reduce the COD treatment efficiency, thereby ensuring that the effluent COD of the oxygen-enriched regulating tank meets the influent requirements of the subsequent biochemical treatment system.

[0030] The sedimentation unit includes a sedimentation tank 401, a sludge return pipe 402, a sludge return pump 403, and a return pipe 404. The sedimentation tank 401 is installed on the right side of the reaction tank 101, the sludge return pipe 402 is installed on the back of the sedimentation tank 401, the sludge return pump 403 is installed on the back of the sludge return pipe 402, and the return pipe 404 is installed on the back of the sludge return pump 403. By installing the sedimentation unit, mud and water separation and residual sludge discharge are performed. After separation, part of the activated sludge is returned to the front aeration tank, and the excess is discharged into the sludge tank for filter pressing treatment.

[0031] An A\O biochemical treatment system 5 is installed on the right side of the sedimentation tank 401.

[0032] Working principle: FeSO4 and PAM coagulant are added to react with SCN in coking wastewater. - , CN - Reaction, in Fe 2+ In the case of excessive amount, water-insoluble Fe4[FeCN6]3 precipitate is generated, thereby achieving the purpose of removing cyanide and reducing the toxicity of the influent. Under the action of gravity, the Fe4[FeCN6]3 precipitate sinks to the bottom of the pool and is discharged into the sludge pool for filter press treatment through the sludge pump. At the same time, the dissolved oxygen in the micro-aeration pool is controlled at 0.5-1 mg / L, providing basic oxygen for the activated sludge. At the same time, in order to ensure the removal efficiency of COD, the sludge concentration in the micro-aeration pool is increased from 4000 to 1000 by controlling the discharge of residual sludge. mg / L is increased to 8000mg / L. After being treated in the micro-oxygen aeration tank, the influent COD and phenolic compounds are significantly reduced, but they do not reach the influent of the subsequent biochemical treatment system. The dissolved oxygen in the medium oxygen aeration tank can be controlled to 1-2mg / L to further degrade COD and finally control the concentration of effluent COD. If the influent COD is too high, after being treated in the micro-oxygen aeration tank and the medium oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to an oxygen-enriched state to improve the COD treatment efficiency. If the influent COD is low, after being treated in the micro-oxygen aeration tank and the medium oxygen aeration tank, the dissolved oxygen in the oxygen-enriched regulating tank is adjusted to a micro-oxygen state to reduce the COD treatment efficiency and ensure that the effluent COD of the oxygen-enriched regulating tank meets the influent requirements of the subsequent biochemical treatment system, thereby further separating mud and water and discharging excess sludge through sedimentation. Separated activated sludge.

[0033] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims

1. A high-concentration coking wastewater COD degradation device, comprising a reaction tank (101), characterized in that: A degradation device is installed inside the reaction tank (101), and the degradation device comprises a decyanation unit, a micro-oxygen aeration unit, an oxygenated aeration unit, and a precipitation unit. The decyanation unit is installed inside the reaction tank (101), the micro-oxygen aeration unit is installed on the right side of the reaction tank (101), the oxygenated aeration unit is installed on the right side of the reaction tank (101), and the precipitation unit is installed on the right side of the reaction tank (101); The decyanation unit comprises a high-concentration coking wastewater COD inlet pipe (102), a flow meter (103), a COD online detector (104), a stirring assembly (105), a ferrous sulfate addition port (106), and a PAM addition port (107); the high-concentration coking wastewater COD inlet pipe (102) is installed on the left side of the reaction tank (101); the flow meter (103) is installed on the outer surface of the high-concentration coking wastewater COD inlet pipe (102); the COD online detector (104) is installed inside the high-concentration coking wastewater COD inlet pipe (102); the stirring assembly (105) is installed inside the reaction tank (101); the ferrous sulfate addition port (106) is installed on the top of the reaction tank (101); and the PAM addition port (107) is installed on the top of the reaction tank (101); The micro-aerobic aeration unit comprises a micro-aerobic aeration tank (201), an aeration addition pipe (202), a tubular aerator (203), and a dissolved oxygen online detector (204); the micro-aerobic aeration tank (201) is installed on the right side of the reaction tank (101); the aeration addition pipe (202) is installed on the top of the micro-aerobic aeration tank (201); the tubular aerator (203) is installed on the bottom of the aeration addition pipe (202); and the dissolved oxygen online detector (204) is installed inside the micro-aerobic aeration tank (201); The oxygenated aeration unit includes a medium oxygen aeration group and an oxygen-enriched aeration group; The medium oxygen aeration group comprises a mixing aeration tank (301), a second aeration addition pipe (302), a liftable aerator (303), and a second dissolved oxygen online detector (304); the mixing aeration tank (301) is installed on the right side of the micro-aeration aeration tank (201); the second aeration addition pipe (302) is installed on the top of the mixing aeration tank (301); the liftable aerator (303) is installed on the bottom of the second aeration addition pipe (302); and the second dissolved oxygen online detector (304) is installed inside the mixing aeration tank (301); The oxygen-enriched aeration group comprises a baffle, a liftable aerator, an aeration pipe, and a dissolved oxygen detection device, wherein the baffle is installed inside the mixed aeration tank (301), the liftable aerator is installed inside the mixed aeration tank (301), the aeration pipe is installed on the top of the liftable aerator, and the dissolved oxygen detection device is installed inside the mixed aeration tank (301); The sedimentation unit comprises a sedimentation tank (401), a sludge return pipe (402), a sludge return pump (403), and a return pipe (404); the sedimentation tank (401) is installed on the right side of the reaction tank (101); the sludge return pipe (402) is installed on the back side of the sedimentation tank (401); and the sludge return pump (403) is installed on the back side of the sludge return pipe (402).

2. A high-concentration coking wastewater COD degradation device according to claim 1, characterized in that: An A\O biochemical treatment system (5) is installed on the right side of the sedimentation tank (401).

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