Comprehensive treatment system and treatment method for industrial wastewater containing organic fluorine

Abstract

The invention discloses a comprehensive treatment system and treatment method for industrial wastewater containing organic fluorine, electrocatalytic oxidation is carried out through an electrocatalytic oxidation reactor in a physicochemical treatment area, the toxicity of the wastewater containing fluorine is effectively reduced, chain scission is carried out on fluorine-containing organic matter macromolecules, the biodegradability of the wastewater containing fluorine is improved, and the treatment effect is good. The fluorine removal reaction sedimentation tank and the calcium removal reaction sedimentation tank are sequentially adopted to effectively remove most fluorine ions and excessive calcium ions, so that the fluorine ion concentration of the fluorine-containing wastewater reaches 10 mg / L, the biological reaction area and the rear fluorine removal guarantee area are arranged at the rear end, the fluorine ion concentration of effluent is further reduced, fluorine removal is effective, operation is easy and convenient, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the field of wastewater treatment, and in particular to a comprehensive treatment system and method for industrial wastewater containing organic fluorine. Background Art

[0002] In recent years, with the rise of the new energy industry, the fluorine-containing fine chemicals and hydrogen fluoride-related industries have flourished, and the treatment of fluorine-containing wastewater has come along with the development of industrial parks. General wastewater from the production of organic fluorine fine chemicals, including wastewater containing organic fluorine such as fluorine pesticides, fluorine medicines, and fluorine-containing aromatic intermediates, as well as inorganic fluorine wastewater with hydrofluoric acid as raw materials, will cause water and soil pollution if not properly disposed of. Long-term excess will cause poisoning of surrounding humans and livestock, and cause endemic fluorosis. There are strict requirements for the discharge of fluorine-containing wastewater, and projects in key control areas and involving upstream areas of the basin may also propose more stringent standards and requirements. Therefore, the harmless treatment of wastewater containing organic fluorine and the reduction or elimination of its disorderly discharge into the environment have become a hot issue in current research.

[0003] Fluoride ions in most inorganic fluoride wastewater are generally in a free state. Fluoride ions in wastewater can be controlled below 10 mg / L through chemical precipitation, coagulation precipitation, adsorption, ion exchange, membrane filtration and other methods, but organic fluoride in wastewater containing organic fluoride cannot be removed. The bond energy of the fluorine-carbon bond in organic fluoride is very large, and it is difficult to be destroyed under high temperature, strong acid and alkali conditions. Therefore, it has a long-lasting resistance to degradation and is difficult to remove from the solution. Therefore, advanced oxidation technology is often used to destroy the fluorine-carbon bond of organic fluoride, so that the organic fluorine breaks the bond to form fluoride ions, and then the free fluoride ions are treated by the method of treating inorganic fluoride wastewater. Some organic fluorides that are not completely oxidized will be transformed in the biochemical sludge system, and inorganic fluoride will appear, resulting in excessive fluoride ion effluent.

[0004] CN117105478A discloses a method for treating organic fluorine-containing wastewater, wherein the electrocatalytic oxidation technology is used to oxidize various types of organic fluorine-containing wastewater, so that when the fluorine-containing organic matter is oxidized to produce fluorine ions, the fluorine ions can quickly react with the added fluorine ion precipitant, fluorine ion flocculant or fluorine ion complexing agent to form a precipitate or complex, thereby reducing the accumulation of fluorine ions and thus reducing the corrosion of fluorine ions on equipment. After the electrocatalytic oxidation treatment, the fluorine-containing organic matter in the wastewater can be completely oxidized, and the converted fluorine ions can be formed into a precipitate or complex to remove the fluorine ions from the wastewater, thereby achieving the simultaneous removal of organic fluorine and fluorine ions. The invention adds reagents before electrocatalysis, and long-term operation will produce a large amount of precipitate covering the electrode, and the electrocatalytic effect will be weakened.

[0005] CN219279662U A comprehensive deep treatment system for wastewater containing organic fluorine, including a chemical reaction zone, a biological reaction zone and a high-efficiency reaction zone connected in sequence, wherein the chemical reaction zone is provided with a Fenton fluidized bed, and the Fenton fluidized bed is provided with a heterogeneous Fenton catalytic material, so as to effectively degrade organic pollutants such as fluoride in the wastewater, and the subsequent high-efficiency defluorination treatment makes the fluoride emission concentration finally reach the emission requirement of <2mg / L. The front-end defluorination process of the invention adopts "primary defluorination + Fenton fluidized bed + secondary defluorination", and repeatedly adjusts the acid and alkali, which will increase the salinity in the wastewater, which is not conducive to the reaction of the subsequent biochemical system.

[0006] The present invention aims to stably operate and treat wastewater containing organic fluorine, meet the requirements for raising the standard of fluorine ions, ensure the stability of system indicators, and reduce operating costs. Summary of the invention

[0007] Therefore, it is necessary to provide a comprehensive treatment system and method for organic fluorine-containing industrial wastewater to overcome the problems of the prior art in the background technology.

[0008] To achieve the above-mentioned purpose, the present invention provides a comprehensive treatment system for organic fluorine-containing industrial wastewater, including a physicochemical defluorination reaction zone, a biological reaction zone, and a post-defluorination guarantee zone;

[0009] The physicochemical defluorination reaction zone comprises a high-concentration fluorine-containing collection pool, an electrocatalytic oxidation device, a defluorination reaction pool and a decalcification reaction pool which are connected in sequence; the high-concentration fluorine-containing collection pool is connected to the upstream pipelines which produce high-concentration fluorine-containing wastewater, and is used to collect the high-concentration fluorine-containing wastewater, and transport the high-concentration fluorine-containing wastewater to the electrocatalytic oxidation reactor; the electrocatalytic oxidation reactor is used to oxidize part of the fluorine-containing organic matter in the high-concentration fluorine-containing wastewater, and the high-concentration fluorine-containing wastewater after electrocatalytic oxidation is transported to the defluorination reaction pool; calcium chloride and calcium hydroxide are added to the defluorination reaction pool in a certain ratio, and at the same time, PAC reagent is added into the defluorination reaction tank to remove fluoride ions. After the reaction is completed, the fluoride-containing wastewater is transported to the decalcification reaction tank; sodium carbonate and PAC reagent are put into the decalcification reaction tank to remove excess calcium ions. After the reaction is completed, the fluoride-containing wastewater treated in the physicochemical defluorination area is transported to the biological reaction area; the biological reaction area is used to remove other pollutants in the fluoride-containing wastewater. After the biological reaction is completed, the fluoride-containing wastewater is transported to the post-defluorination guarantee area; the post-defluorination guarantee area removes fluoride ions from the fluoride-containing wastewater through precipitation reaction and adsorption to form wastewater that meets the standards and can be discharged.

[0010] Furthermore, the biological reaction zone includes a hydrolysis acidification tank, a primary AO treatment tank and a secondary AO treatment tank which are connected in sequence.

[0011] Furthermore, the post-defluorination guarantee area includes an air flotation defluorination device, and is added with a defluorination agent, a coagulant or flocculant, and a liquid alkali agent.

[0012] Furthermore, it also includes a sludge pool, which is used to receive the sediments produced by the defluorination reaction tank, the decalcification reaction tank, the biological reaction area, and the post-defluorination guarantee area.

[0013] Furthermore, it also includes sludge drying equipment for low-temperature drying of sediment in the sludge pool.

[0014] Furthermore, a buffer tank is also included, and the fluorine-containing wastewater treated in the physicochemical defluorination reaction zone enters the biological reaction zone after passing through the buffer tank.

[0015] Furthermore, it also includes a blending tank. After the fluorine-containing wastewater buffered by the buffer tank enters the blending tank, the blended wastewater is added to the blending tank. After the COD concentration and ammonia nitrogen concentration of the fluorine-containing wastewater are adjusted to less than the designed concentration in the blending tank, it enters the biological reaction area.

[0016] The present invention also provides a method for comprehensive treatment of industrial wastewater containing organic fluorine, which is treated by using the comprehensive treatment system for industrial wastewater containing organic fluorine described in any of the above technical solutions.

[0017] Different from the existing technology, the above technical scheme can reduce the toxicity of wastewater, break the chains of macromolecules and improve the biodegradability of wastewater by electrocatalytic oxidation in the physicochemical treatment area, and successively use the defluorination reaction sedimentation tank and the decalcification reaction sedimentation tank to effectively remove most of the fluoride ions and excess calcium ions. The fluoride ion concentration reaches 10 mg / L, and a biological reaction area and a post-defluorination guarantee area are configured at the rear end to further reduce the fluoride ion concentration of the effluent. The defluorination is effective, the operation is simple and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a process flow chart of a comprehensive treatment system for organic industrial wastewater according to a specific implementation method. DETAILED DESCRIPTION

[0019] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0020] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0021] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0022] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0023] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0024] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0025] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0026] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0027] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0028] See also Figure 1 The present invention provides a comprehensive treatment system for organic fluorine-containing industrial wastewater, including a physical and chemical defluorination reaction zone, a biological reaction zone, and a post-defluorination guarantee zone;

[0029] The physicochemical defluorination reaction zone comprises a high-concentration fluorine-containing collection pool, an electrocatalytic oxidation device, a defluorination reaction pool and a decalcification reaction pool which are connected in sequence; the high-concentration fluorine-containing collection pool is connected to the upstream pipelines which produce high-concentration fluorine-containing wastewater, and is used to collect the high-concentration fluorine-containing wastewater, and transport the high-concentration fluorine-containing wastewater to the electrocatalytic oxidation reactor; the electrocatalytic oxidation reactor is used to oxidize part of the fluorine-containing organic matter in the high-concentration fluorine-containing wastewater, and the high-concentration fluorine-containing wastewater after electrocatalytic oxidation is transported to the defluorination reaction pool; calcium chloride and calcium hydroxide are added to the defluorination reaction pool in a certain ratio, and at the same time, PAC reagent is added into the defluorination reaction tank to remove fluoride ions. After the reaction is completed, the fluoride-containing wastewater is transported to the decalcification reaction tank; sodium carbonate and PAC reagent are put into the decalcification reaction tank to remove excess calcium ions. After the reaction is completed, the fluoride-containing wastewater treated in the physicochemical defluorination area is transported to the biological reaction area; the biological reaction area is used to remove other pollutants in the fluoride-containing wastewater. After the biological reaction is completed, the fluoride-containing wastewater is transported to the post-defluorination guarantee area; the post-defluorination guarantee area removes fluoride ions from the fluoride-containing wastewater through precipitation reaction and adsorption to form wastewater that meets the standards and can be discharged.

[0030] Electrocatalytic oxidation equipment uses the principle of electrolytic cell to directly and indirectly oxidize organic matter in fluorine-containing wastewater. Direct oxidation means that the surface of the anode plate electrode of the electrocatalytic equipment directly participates in the reaction to generate strong oxidizing free radicals (such as -OH) and oxidatively degrade with fluorine-containing organic matter. During this reaction, the fluorine-containing organic matter on the surface of the electrode plate loses an electron to form a free radical, which is then oxidized and degraded into inorganic matter or low-toxic substances. Indirect oxidation means using electrochemically generated redox substances as reactants or catalysts to convert fluorine-containing organic matter into less toxic substances. Commonly used electrode materials include graphene, precious metals, PbO2, TiO2, etc. These materials produce strongly oxidizing intermediates (such as -OH, -O2, O3, H2O2, etc.) during the electrolysis process. These intermediates further react with fluorine-containing organic matter to degrade it into inorganic matter or low-toxic substances. After electrocatalytic oxidation treatment, long-chain and cyclic organic matter undergo ring-opening and chain-breaking reactions to generate short-chain, easily degradable organic matter, thereby improving biodegradability and reducing toxicity.

[0031] The high-concentration fluoride-containing wastewater after electrocatalytic oxidation contains a large amount of fluoride ions. The present invention adopts "double calcium defluorination" for efficient removal, that is, calcium chloride and calcium hydroxide are mixed in a certain ratio. It should be noted that the dosage ratio of calcium chloride and calcium hydroxide can be adjusted according to the specific situation, that is, it is adjusted according to the concentration of fluoride ions in the defluorination reaction tank. Under normal circumstances, a 1:1 ratio can be used for addition. In order to ensure the defluorination effect, excessive calcium chloride and calcium hydroxide can be added to provide excessive calcium ions to ensure sufficient reaction. Excess calcium ions can be removed in the subsequent decalcification reaction tank. The specific method is to add sodium carbonate and PAC to allow excess calcium ions to react and precipitate.

[0032] PAC is a polyaluminium chloride, which cannot directly remove fluoride ions by itself. It can mix with fluoride ions to form a water-insoluble calcium carbonate precipitate, which can remove fluoride ions from water in the subsequent precipitation process. In addition, the hydrolysis reaction that occurs during the PAC treatment process may also have an impact on fluoride, such as the production of hydrofluoric acid, and these chemicals will play a certain auxiliary role in the removal of fluoride. The same applies to adding PAC to the decalcification reaction tank.

[0033] The fluoride ion concentration of the high-concentration fluoride-containing wastewater after treatment in this embodiment is 10-13 mg / L.

[0034] Furthermore, the biological reaction zone includes a hydrolysis acidification tank, a primary AO treatment tank and a secondary AO treatment tank which are connected in sequence.

[0035] The hydrolysis acidification tank can decompose the complex organic matter in the wastewater into simple organic matter, such as fatty acids, amino acids and sugars, through the action of microorganisms, thereby improving the biodegradability of the wastewater. During the anaerobic digestion process, the simple organic matter is further converted into volatile fatty acids (VFAs), such as acetic acid, propionic acid and butyric acid, and then produces methane gas. The hydrolysis acidification tank can reduce the concentration and load of organic matter through the hydrolysis and anaerobic digestion process, making it easier for subsequent treatment units to handle the remaining organic matter. Due to the degradation of some organic matter, the organic load required by the microorganisms in the subsequent treatment unit is relatively low, thereby reducing the amount of sludge produced.

[0036] The primary AO treatment pool and the secondary AO treatment pool provided in this embodiment are mainly used to remove nutrients such as organic matter, nitrogen and phosphorus. The primary AO treatment pool utilizes the anaerobic section and the aerobic section in series to remove organic matter and ammonia nitrogen from sewage through hydrolysis acidification under anaerobic conditions and biological oxidation reaction under aerobic conditions. The secondary AO treatment pool further processes the effluent from the primary AO treatment pool, and further organic matter degradation and nitrogen and phosphorus removal are achieved through the alternating effects of anoxic and aerobic conditions. This process can effectively remove pollutants such as organic matter and ammonia nitrogen from sewage, improve the effluent water quality, and meet the discharge standards.

[0037] Through continuous anaerobic and aerobic reactions in the biochemical reaction zone, organic fluorine compounds may be further broken by microorganisms during the treatment process of the biochemical system to release fluoride ions. In order to ensure that the fluoride ions in the effluent meet the requirements, a fluoride removal guarantee zone is set up to achieve a lower fluoride content in the effluent.

[0038] Furthermore, the post-defluorination guarantee area includes an air flotation defluorination device, and is added with a defluorination agent, a coagulant or flocculant, and a liquid alkali agent.

[0039] The principle of the flotation defluorination device is mainly to remove fluoride ions from wastewater by physical and chemical methods. It uses aluminum salt flocculants to undergo adsorption, ion exchange and complex precipitation reactions with fluoride ions to form water-insoluble precipitates, and then uses flotation technology to achieve solid-liquid separation, thereby removing fluoride ions. Flotation technology uses a dissolved air releaser to produce a large number of fine bubbles, which combine with flocculants in the wastewater to make their density less than that of water, thereby achieving solid-liquid separation. The coagulant can be PAC, and the flocculant can be PAM. The flotation defluorination device effectively removes fluoride ions from wastewater through flocculation and flotation processes, further reducing the fluoride concentration and achieving an outlet fluoride content of less than 6 mg / L.

[0040] Taking PAC as an example, aluminum sulfate undergoes precipitation reaction and adsorption after being dissolved in water. By properly controlling the reaction conditions, such as controlling the dosage of defluoridation agent and flocculant, the best effect can be determined through experiments; the influent pH is in the range of 7-8; and the reaction time between the agent and the wastewater is adjusted. Fluoride ions in wastewater can be effectively removed. It should be noted that the pH will decrease after adding the defluoridation agent, which can be adjusted by liquid alkali.

[0041] Furthermore, it also includes a sludge pool, which is used to receive the sediments produced by the defluorination reaction tank, the decalcification reaction tank, the biological reaction area, and the post-defluorination guarantee area.

[0042] The sludge tank mainly settles the sludge by gravity. When each sediment enters the sludge tank, the suspended matter and solid particles therein settle naturally under the action of gravity, thus achieving solid-liquid separation.

[0043] Furthermore, it also includes sludge drying equipment for low-temperature drying of sediment in the sludge pool.

[0044] In order to reduce the moisture content of sludge, sludge drying equipment is used to further reduce the moisture content of sludge through physical methods, so as to facilitate the transportation, accumulation, utilization or further treatment of sludge.

[0045] Furthermore, a buffer tank is included, and the fluorine-containing wastewater treated in the physicochemical defluorination reaction zone enters the biological reaction zone after passing through the buffer tank. The buffer tank can further reduce the content of suspended matter in the water, which is convenient for subsequent further defluorination treatment.

[0046] Furthermore, it also includes a blending tank. After the fluorine-containing wastewater buffered by the buffer tank enters the blending tank, the blended wastewater is added to the blending tank. After the pH, COD, ammonia nitrogen and salinity of the fluorine-containing wastewater are blended in the blending tank to meet the design requirements, it enters the biochemical reaction zone. The blended wastewater includes MVR wastewater, low-concentration wastewater and domestic wastewater. The blended wastewater is formed by mixing MVR wastewater, low-concentration wastewater and domestic wastewater in a certain proportion, and the blended wastewater is mixed with the fluorine-containing wastewater in the blending tank to ensure that the indicators entering the biochemical treatment system meet the standards and avoid impact on the system that exceeds the design requirements.

[0047] The present invention adopts a process combining electrocatalytic oxidation and double calcium defluorination in the physical and chemical defluorination reaction zone, which can not only improve the biodegradability of sewage, reduce toxicity, provide protection for the subsequent biochemical system, but also remove most of the fluoride ions. It has the characteristics of simple operation, cheap and easy availability of reagents (mainly lime and flocculants), and relatively low operating costs. After passing through the biological reaction zone, all indicators except fluoride ions meet the standards. Some of the indicators are as follows: COD <500mg / L, ammonia nitrogen <45mg / L, total nitrogen <50mg / L, pH = 6-9. The flotation defluorination process can effectively treat the organic fluorine converted in the biochemical system, and further efficiently remove the fluoride reaction treatment, so that the fluoride emission concentration finally reaches the emission requirement of <6mg / L.

[0048] The present invention also provides a method for comprehensive treatment of industrial wastewater containing organic fluorine, which is treated by using the comprehensive treatment system for industrial wastewater containing organic fluorine described in any of the above technical solutions.

[0049] The present invention can reduce the toxicity of wastewater, break the chain of macromolecules, and improve the biodegradability of wastewater by performing electrocatalytic oxidation in the physical and chemical treatment area, and sequentially adopts a defluorination reaction sedimentation tank and a decalcification reaction sedimentation tank to effectively remove most of the fluoride ions and excess calcium ions, and the fluoride ion concentration reaches 10mg / L, and the defluorination is effective, easy to operate, and low in cost. In order to cope with the situation that organic fluorine may be converted into inorganic fluorine in the biochemical system process, a post-defluorination guarantee area is equipped at the end, and the defluorination agent is efficiently operated through the flotation device to ensure that the effluent meets the discharge requirement of <6mg / L (park management standard).

[0050] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included in the patent protection scope of the present invention.

Claims

1. A comprehensive treatment system for organic fluorine-containing industrial wastewater, characterized by: It includes the physical and chemical defluorination reaction area, biological reaction area and post-defluorination guarantee area; The physicochemical defluorination reaction zone comprises a high-concentration fluorine-containing collection pool, an electrocatalytic oxidation device, a defluorination reaction pool and a decalcification reaction pool which are connected in sequence; the high-concentration fluorine-containing collection pool is connected to the upstream pipelines which produce high-concentration fluorine-containing wastewater, and is used to collect the high-concentration fluorine-containing wastewater, and transport the high-concentration fluorine-containing wastewater to the electrocatalytic oxidation reactor; the electrocatalytic oxidation reactor is used to oxidize part of the fluorine-containing organic matter in the high-concentration fluorine-containing wastewater, and the high-concentration fluorine-containing wastewater after electrocatalytic oxidation is transported to the defluorination reaction pool; calcium chloride and calcium hydroxide are added to the defluorination reaction pool in a certain ratio, and at the same time, PAC reagent is added into the defluorination reaction tank to remove fluoride ions. After the reaction is completed, the fluoride-containing wastewater is transported to the decalcification reaction tank; sodium carbonate and PAC reagent are put into the decalcification reaction tank to remove excess calcium ions. After the reaction is completed, the fluoride-containing wastewater treated in the physicochemical defluorination area is transported to the biological reaction area; the biological reaction area is used to remove other pollutants in the fluoride-containing wastewater. After the biological reaction is completed, the fluoride-containing wastewater is transported to the post-defluorination guarantee area; the post-defluorination guarantee area removes fluoride ions from the fluoride-containing wastewater through precipitation reaction and adsorption to form wastewater that meets the standards and can be discharged.

2. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 1 is characterized in that: The biological reaction zone includes a hydrolysis acidification tank, a primary AO treatment tank and a secondary AO treatment tank which are connected in sequence.

3. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 2 is characterized in that: The post-defluorination protection area includes an air flotation defluorination device, and is added with a defluorination agent, a coagulant or a flocculant, and a liquid alkali agent.

4. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 3 is characterized by: It also includes a sludge pool, which is used to receive the sediments produced by the defluorination reaction tank, the decalcification reaction tank, the biological reaction area, and the post-defluorination guarantee area.

5. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 4 is characterized in that: It also includes sludge drying equipment for low-temperature drying of sediment in the sludge pool.

6. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 1 is characterized by: It also includes a buffer tank, and the fluorine-containing wastewater treated in the physicochemical defluorination reaction zone enters the biological reaction zone after passing through the buffer tank.

7. The comprehensive treatment system for organic fluorine-containing industrial wastewater according to claim 6 is characterized by: It also includes a blending tank. After the fluorine-containing wastewater buffered in the buffer tank enters the blending tank, the blended wastewater is added to the blending tank. After the COD concentration and ammonia nitrogen concentration of the fluorine-containing wastewater are adjusted to less than the designed concentration in the blending tank, it enters the biological reaction area.

8. A comprehensive treatment method for organic fluorine-containing industrial wastewater, characterized by: The treatment is carried out using the comprehensive treatment system for organic fluorine-containing industrial wastewater as described in any one of claims 1 to 7.

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