A cerium and nitrogen-containing organic mixed wastewater treatment system

Abstract

The utility model relates to a kind of cerium, nitrogen organic mixed wastewater treatment system, comprising: collection unit, including high concentration wastewater collection tank;Pretreatment unit, including the cerium removal precipitation device for precipitating cerium ion in wastewater and the advanced oxidation device for carrying out advanced oxidation to wastewater, the cerium removal precipitation device and advanced oxidation device are sequentially connected, and the cerium removal precipitation device is connected in high concentration wastewater collection tank;Microbial treatment unit, including the hydrolytic acidification pond, facultative pond, aerobic tank and membrane bioreactor that are sequentially communicated, the membrane bioreactor is connected with mixed liquor reflux pipeline, the mixed liquor reflux pipeline is connected in hydrolytic acidification pond and facultative pond, and the mixed liquor of the membrane bioreactor is backflowed to hydrolytic acidification pond and facultative pond by mixed liquor reflux pipeline.The utility model is combined by the structure of chemical precipitation cerium removal, advanced oxidation, biochemical denitrification, and can realize the synergistic efficient removal of cerium, nitrogen, organic matter.

Description

Technical Field

[0001] This utility model relates to the field of water pollution treatment technology, specifically to a treatment system for cerium- and nitrogen-containing organic mixed wastewater. Background Technology

[0002] Industries such as glass ceramics, catalyst manufacturing, and alloy additive manufacturing generate large quantities of complex, high-concentration cerium- and nitrogen-containing organic wastewater. Cerium is biotoxic, and without pretreatment, it can impact subsequent biochemical treatment and harm the ecological environment. Furthermore, the complex composition of cerium- and nitrogen-containing organic wastewater makes it difficult to treat effectively with a single process. While cross-treatment of cerium ions and nitrate nitrogen is possible, it is difficult to reduce cerium ion levels to a low level, and the treatment costs are high.

[0003] In existing technologies, the treatment of cerium-containing wastewater mainly employs adsorption, membrane methods, or chemical precipitation. Adsorption and membrane methods are costly, and adsorption is primarily suitable for low-concentration wastewater. Traditional chemical precipitation methods (such as those using ammonium bicarbonate) introduce large amounts of ammonia nitrogen, causing secondary pollution. Furthermore, for nitrogen-containing organic wastewater, evaporation poses a safety risk of high-temperature explosion when nitrate nitrogen is present. Therefore, there is an urgent need to develop an integrated treatment system that can synergistically remove cerium, nitrogen, and organic matter, while being economical, safe, and efficient. Utility Model Content

[0004] The purpose of this invention is to provide a treatment system for cerium- and nitrogen-containing organic mixed wastewater, which can solve the technical problems mentioned in the background section.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a cerium- and nitrogen-containing organic mixed wastewater treatment system, comprising a collection unit, a pretreatment unit, and a microbial treatment unit. The collection unit includes a high-concentration wastewater collection tank; the pretreatment unit includes a cerium removal precipitation device for precipitating cerium ions in the wastewater and an advanced oxidation device for advanced oxidation of the wastewater, wherein the cerium removal precipitation device and the advanced oxidation device are connected in sequence, and the cerium removal precipitation device is connected to the high-concentration wastewater collection tank; the microbial treatment unit includes a hydrolysis acidification tank, an anoxic tank, an aerobic tank, and a membrane bioreactor connected in sequence, wherein the membrane bioreactor is connected to a mixed liquor return pipeline, which is connected to the hydrolysis acidification tank and the anoxic tank respectively, and the mixed liquor from the membrane bioreactor is returned to the hydrolysis acidification tank and the anoxic tank through the mixed liquor return pipeline.

[0006] In a preferred embodiment, the cerium removal precipitation device includes a precipitation reactor and a solid-liquid separation device connected thereto, wherein the precipitation reactor is equipped with a dosing mechanism for adding sodium carbonate.

[0007] In a preferred embodiment, the solid-liquid separation device is a centrifuge or a plate and frame filter press.

[0008] In a preferred embodiment, the advanced oxidation apparatus includes a micro-electrolysis Fenton reactor, a coagulation sedimentation tank, and a high-concentration conditioning tank connected in sequence.

[0009] In a preferred embodiment, the collection unit further includes a low-concentration wastewater collection tank, which is connected to a low-concentration equalization tank, and the low-concentration equalization tank and the high-concentration equalization tank are connected to a comprehensive equalization tank.

[0010] In a preferred embodiment, the microbial treatment unit further includes an intermediate sedimentation tank connected between the hydrolysis acidification tank and the anaerobic tank, and a sludge return pipeline for returning sludge from the intermediate sedimentation tank to the hydrolysis acidification tank.

[0011] In a preferred embodiment, the microbial treatment unit further includes a sludge treatment device, which includes a sludge tank connected to the membrane bioreactor and an intermediate sedimentation tank.

[0012] In a preferred embodiment, the sludge treatment apparatus further includes a screw filter press connected to the sludge tank.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] The cerium- and nitrogen-containing organic mixed wastewater treatment system provided by this utility model achieves synergistic and efficient removal of cerium, nitrogen, and organic matter through a structural combination of chemical precipitation for cerium removal, advanced oxidation, and biochemical denitrification. By setting an intermediate sedimentation tank and a sludge return structure at the rear end of the hydrolysis acidification structure, the sludge loss in the hydrolysis acidification tank can be effectively reduced, enhancing the stability of the denitrification system. Furthermore, by setting up a membrane bioreactor, the sludge concentration can be guaranteed, the sludge age can be extended, and the normal generation cycle of nitrifying bacteria can be guaranteed. In addition, the high aeration and low load environment of the membrane tank can promote the growth and reproduction of nitrifying bacteria and ensure the activity of the bacterial community. Attached Figure Description

[0015] Figure 1 This is a flowchart of the treatment system for cerium- and nitrogen-containing organic mixed wastewater in this embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the cerium removal precipitation device in the pretreatment unit of this utility model embodiment;

[0017] Figure 3 This is a schematic diagram of the advanced oxidation device in the pretreatment unit of this utility model embodiment;

[0018] Figure 4This is a schematic diagram of the structure of the integrated regulating tank in an embodiment of this utility model;

[0019] Figure 5 This is a schematic diagram of the structure of the microbial treatment unit in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the sludge treatment device in an embodiment of this utility model.

[0021] The meanings of the labels in the diagram are as follows:

[0022] 1. Collection Unit; 11. High-Concentration Wastewater Collection Tank; 12. Low-Concentration Wastewater Collection Tank; 2. Pretreatment Unit; 21. Sedimentation Reactor; 211. Dosing Mechanism; 212. Acid / Alkali Inlet Pipeline; 213. Screw Pump; 22. Solid-Liquid Separation Equipment; 23. High-Concentration Collection Tank; 24. Micro-Electrolysis Fenton Reactor; 25. Coagulation Sedimentator; 251. PAM Dosing Machine; 26. High-Concentration Equalization Tank; 27. Low-Concentration Equalization Tank; 28. Integrated Equalization Tank; 3. Microbial Treatment Unit; 31. Hydrolysis Acidification Tank; 32. Anoxic Tank; 33. Aerobic Tank; 34. Membrane Bioreactor; 35. Effluent Tank; 36. Intermediate Sedimentation Tank; 41. Mixed Liquor Return Pipeline; 42. Mixed Liquor Return Pump; 51. Sludge Return Pipeline; 52. Sludge Return Pump; 61. Sludge Tank; 62. Screw Filter Press; 63. Sludge Discharge Pump. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0025] See Figure 1This embodiment discloses a treatment system for cerium- and nitrogen-containing organic mixed wastewater, including a collection unit 1, a pretreatment unit 2, and a microbial treatment unit 3. The collection unit 1 is used for collecting and storing wastewater, the pretreatment unit 2 is used to remove cerium ions from the wastewater and perform advanced oxidation on the wastewater to reduce the load and toxicity of subsequent biochemical treatment, and the microbial treatment unit 3 is used for biodegradation.

[0026] Specifically, the collection unit 1 includes a high-concentration wastewater collection tank 11 and a low-concentration wastewater collection tank 12. The high-concentration wastewater collection tank 11 is used to collect high-concentration organic mixed wastewater containing cerium and nitrogen generated in the production workshop, while the low-concentration wastewater collection tank 12 is used to collect low-concentration wastewater from the production workshop, mainly including low-concentration rinsing wastewater and domestic sewage.

[0027] See Figure 2 , Figure 3 The pretreatment unit 2 includes a cerium removal precipitation device for precipitating cerium ions in wastewater and an advanced oxidation device for advanced oxidation of wastewater. The cerium removal precipitation device and the advanced oxidation device are connected in sequence, and the cerium removal precipitation device is connected to the high-concentration wastewater collection tank 11.

[0028] See Figure 2 In a preferred embodiment, the cerium removal precipitation device includes a precipitation reactor 21 and a solid-liquid separation device 22 connected thereto. The precipitation reactor 21 is equipped with a dosing mechanism 211, which is used to add chemicals to convert cerium ions in the wastewater into insoluble precipitates, making them easy to separate. More preferably, the dosing mechanism 211 is used to add sodium carbonate to the precipitation reactor 21. Using sodium carbonate as a precipitant can effectively avoid the secondary pollution problem of ammonia nitrogen caused by the use of traditional reagents such as ammonium bicarbonate, and the generated cerium precipitate has a loose structure, making it easier to separate mud and water by centrifugation or filter press. The precipitation reactor 21 is also equipped with an acid-base inlet pipeline 212, a pH meter, a level gauge, and a thermometer to achieve automatic control of pH, temperature, and level. The solid-liquid separation device 22 is used to separate the precipitate. For example, the solid-liquid separation device 22 can be a centrifuge or a plate and frame filter press in the prior art, and its rear end is connected to a high-concentration collection tank 23 for filtrate collection.

[0029] In practical applications, high-concentration cerium and nitrogen-containing organic mixed wastewater is discharged into sedimentation reactor 21 through high-concentration wastewater collection tank 11. Chemicals are added into sedimentation reactor 21 and pH is adjusted through dosing mechanism 211. The mixture is stirred evenly through its internal stirring structure. Then, it is discharged into plate and frame filter press or centrifuge through screw pump 213 for solid-liquid separation. The filtrate is discharged into high-concentration collection tank 23, and the sludge is transported off-site.

[0030] See Figure 3The advanced oxidation unit is connected after the cerium removal precipitation unit to further degrade recalcitrant organic matter in the filtrate and reduce wastewater toxicity. It includes a micro-electrolysis Fenton reactor 24, a coagulation sedimentation unit 25, and a high-concentration equalization tank 26 connected in sequence. The micro-electrolysis Fenton reactor 24 automatically adds acid and hydrogen peroxide through a pH meter and an ORP automatic controller to degrade large molecular organic matter in the wastewater into biodegradable small molecular organic matter. After the reaction is completed, the wastewater is transported to the coagulation sedimentation unit 25. The coagulation sedimentation unit 25 is equipped with a pH meter and a PAM dosing machine 251, which can flocculate and precipitate flocculents, particles, and iron sludge in the wastewater. The sludge is discharged into the plate and frame filter press at the front end by a screw pump 213 for filtration treatment, and the clear liquid is discharged into the high-concentration equalization tank 26.

[0031] See Figure 4 In this embodiment, the pretreatment unit 2 also includes a low-concentration regulating tank 27 connected to the low-concentration wastewater collection tank 12, and the workshop domestic low-concentration pipeline is also connected to the low-concentration regulating tank 27.

[0032] Preferably, the pretreatment unit 2 further includes a comprehensive equalization tank 28 connected to the high-concentration equalization tank 26 and the low-concentration equalization tank 27. The wastewater in the high-concentration equalization tank 26 and the low-concentration equalization tank 27 flows into the comprehensive equalization tank 28. The comprehensive equalization tank 28 is used to balance the water quality and quantity of the pretreated high-concentration wastewater with other low-concentration wastewater. It is equipped with a level gauge, pH meter, TDS meter and automatic water distribution structure. It can automatically adjust the COD, ammonia nitrogen, total nitrogen, pH and TDS of the wastewater to a reasonable range according to the wastewater information. After the adjustment is completed, the wastewater is transported to the microbial treatment unit 3. In this embodiment, the level gauge, pH meter, TDS meter and automatic water distribution structure all adopt existing technology.

[0033] See Figure 5The microbial treatment unit 3 is used for the deep removal of organic pollutants and nitrogen, and includes a hydrolysis acidification tank 31, an anoxic tank 32, an aerobic tank 33, a membrane bioreactor 34 (MBR), and an effluent tank 35 arranged sequentially along the water flow direction. The hydrolysis acidification tank 31 is equipped with a submersible mixer to enhance sludge-water mixing and prevent sludge deposition. The hydrolytic and acidifying bacteria in the hydrolysis acidification tank 31 further decompose large-molecule organic matter in the wastewater into more easily degradable small-molecule fatty acids, alcohols, and other organic matter. Organic ammonia is decomposed into ammonia or ammonium salts. The hydrolyzed and acidified wastewater is then transported to the anoxic tank 32, which is also equipped with a submersible mixer and aeration devices to prevent sludge settling and to periodically replenish oxygen, preventing the formation of an anaerobic environment. Denitrification occurs in the anoxic tank 32, converting nitrate nitrogen and nitrite nitrogen into nitrogen gas, thus removing total nitrogen. The liquid then overflows sequentially into the aerobic tank 33 and the membrane bioreactor 34. Both the aerobic tank 33 and the membrane bioreactor 34 are equipped with aeration devices to provide an aerobic environment, ensure the metabolic activity of aerobic bacteria, further degrade organic matter in the wastewater, and carry out nitrification to remove ammonia nitrogen from the wastewater. The membrane bioreactor 34 can effectively increase sludge concentration, ensure sludge activity and stability, and extend the microbial generation cycle.

[0034] like Figure 5 As shown, the membrane bioreactor 34 is also connected to a mixed liquor return pipeline 41, which is connected to the hydrolysis acidification tank 31 and the anoxic tank 32. The mixed liquor of the membrane bioreactor 34 is returned to the hydrolysis acidification tank 31 and the anoxic tank 32 through the mixed liquor return pump 42, transferring the nitrate nitrogen and nitrite nitrogen produced by the nitrification reaction to the hydrolysis acidification tank 31 and the anoxic tank 32, thus completing the denitrification reaction cycle.

[0035] In a preferred embodiment, the microbial treatment unit 3 further includes an intermediate sedimentation tank 36 connected between the hydrolysis acidification tank 31 and the anaerobic tank 32. The intermediate sedimentation tank 36 is connected to the hydrolysis acidification tank 31 through a sludge return pipeline 51 equipped with a sludge return pump 52. The intermediate sedimentation tank 36 is used for sludge settling. This structure enables the activated sludge lost in the hydrolysis acidification tank 31 to be effectively intercepted and returned, which significantly improves the sludge concentration and microbial quantity in the hydrolysis acidification tank 31.

[0036] Understandably, dissolved oxygen meters, sludge concentration meters, and thermometers can be installed in the anaerobic tank 32, aerobic tank 33, and membrane bioreactor 34 as needed to optimize the biochemical reaction environment.

[0037] See Figure 6Preferably, the microbial treatment unit 3 also includes a sludge treatment device, which includes a sludge tank 61 and a screw filter press 62. The sludge tank 61 is connected to the membrane bioreactor 34 and the intermediate sedimentation tank 36. A portion of the sludge and mixed liquor from the intermediate sedimentation tank 36 are transferred to the sludge tank 61 by a sludge return pump 52 and a mixed liquor return pump 42, respectively, and the remaining sludge is discharged to ensure a stable sludge concentration. The sludge in the sludge tank 61 is transferred to the screw filter press 62 for filtration by a sludge discharge pump 63.

[0038] The cerium- and nitrogen-containing organic mixed wastewater treatment system provided in this embodiment uses a combination of chemical precipitation to remove cerium, advanced oxidation, and biochemical denitrification to pretreat high concentrations of cerium in wastewater to below 10 mg / L, achieving synergistic and efficient removal of cerium, nitrogen, and organic matter.

[0039] It is understood that this application uses a control system for control. The control system is electrically connected to the pH meter, level gauge, and thermometer installed in the sedimentation reactor 21, the level gauge, pH meter, and TDS meter installed in the integrated regulating tank 28, as well as various liquid addition mechanisms, pumps, and aeration devices. It is used to automatically control the operation of related equipment based on the detection data. The control method of the control system can be implemented by simple programming by those skilled in the art and is common knowledge in the field. Therefore, the control method will not be explained in detail in this embodiment.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

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