Method and device for treating supersaturated chlorobenzene-containing organic wastewater

Abstract

The present invention discloses a method and apparatus for treating supersaturated chlorobenzene-containing organic wastewater, belonging to the technical field of high-concentration organic wastewater treatment. The technical solution is as follows: a method for treating supersaturated chlorobenzene-containing organic wastewater, comprising the following steps: 1) separation and dissolution of undissolved chlorobenzene; 2) oxidation of chlorobenzene and regeneration of filler; 3) complete oxidation of chlorobenzene and its intermediates; and 4) flocculation and sedimentation. The apparatus comprises a primary reaction tower, a secondary reactor, and a flocculation sedimentation tank, connected in sequence by pipelines. The primary reaction tower is provided with a wastewater inlet pipeline and a primary reaction tower outlet pipeline. The primary reaction tower outlet pipeline is provided with an acid feed pipeline, an oxidant or catalyst feed pipeline, and a primary UV reactor. A secondary UV reactor is provided in the pipeline between the primary reaction tower and the secondary reactor. The invention is suitable for treating high-concentration / supersaturated chlorobenzene-containing organic wastewater and high-concentration / supersaturated chlorobenzene-containing organic wastewater treatment processes.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-concentration organic wastewater treatment, and in particular relates to a method and device for treating supersaturated chlorobenzene-containing organic wastewater. Background Art

[0002] With the development of modern chemical industry, organic additives are used more and more widely. However, while producing high-quality products, the added organic additives are often discharged with wastewater. In the process of production equipment process design, stripping towers are generally designed to recover organic additives. However, since some additives have low solubility in water, the recovery process often leads to unstable operation of the recycling facilities, and supersaturated organic wastewater is discharged from the production equipment. If it is sent directly to a sewage field or treatment facility, the supersaturated precipitated organic matter will remain at the bottom or top of the structure and be released persistently, greatly increasing the difficulty of treatment. Therefore, this type of wastewater is often sent to an accident tank for temporary storage, and finally treated as hazardous waste at a high cost, which is contrary to the concept of green and high-quality development of the enterprise.

[0003] Chlorobenzene is a typical organic auxiliary agent that is colorless, transparent, and volatile. It can be used as an intermediate and solvent in organic synthesis and has a wide range of uses. Under normal circumstances, chlorobenzene has a low solubility in water. Once supersaturated wastewater is generated, chlorobenzene will settle to the bottom of the accident tank or the reactor or structure of the treatment facility, causing a lasting impact on the downstream sewage treatment facilities and leading to unstable operation. Chlorobenzene is biologically toxic. Chlorobenzene-containing wastewater, especially supersaturated chlorobenzene wastewater, cannot be treated by biological treatment methods. Advanced oxidation processes are generally used. When using advanced oxidation processes, chlorobenzene is easily generated into intermediates such as chlorophenol, diphenol, and quinone under the action of advanced oxidation factors. These intermediates are still environmentally toxic substances and must be further carbonized in time to remove the toxicity. At present, during the treatment of supersaturated chlorobenzene, these toxic intermediates are difficult to remove completely, resulting in the effluent still containing toxicity.

[0004] Chinese invention patent CN115536187A discloses a method and device for treating chlorobenzene-containing wastewater. The wastewater first enters a homogenization tank for buffering, then mixes with the water from the bottom outlet of the oxidation tank and the chlorobenzene waste gas from the top of the homogenization tank before entering a UV generator for oxidation cycle treatment. The water effluent from the top of the oxidation tank is pH-adjusted and then enters a laminated filter to retain the catalyst solid particles. The water effluent from the filter is pH-adjusted again to a monitoring pool before being discharged to meet the standards. The backwash water from the laminated filter contains catalyst and enters a catalyst tank for catalyst recovery. The recovered catalyst is then injected into the oxidation tank via a reagent pump. The exhaust gas is discharged from the top of the oxidation tank to meet the standards. The waste gas is introduced into the wastewater treatment pipeline, and the wastewater and waste gas are treated using the same device, saving subsequent waste gas investment and land occupation. Alkali solution is added in batches, saving the amount of acid added for backwashing the laminated filter. The catalyst is recovered and recycled after a single addition, improving oxidation efficiency while not generating waste residue. This invention patent provides an efficient method for treating chlorobenzene wastewater. However, when treating chlorobenzene concentrations reaching 400 mg / L or supersaturated chlorobenzene wastewater, it is difficult to control the chlorobenzene content in the effluent to meet the standards because the chlorobenzene liquid phase dissolves while oxidizing during the oxidation process. The method can only be used to reduce the efficiency of the device and gradually degrade chlorobenzene and intermediate products in a cyclic treatment process until the standards are met. This method requires a long treatment time and high energy consumption. When the chlorobenzene liquid phase concentration is relatively high, the retention of intermediate products causes the wastewater oxidation process to darken in color, further reducing the photooxidation efficiency.

[0005] Chinese invention patent CN106865825A discloses a method for treating wastewater containing benzene and chlorobenzene. The method involves first adjusting the pH of the wastewater to be treated, adding a flocculant, and mixing the mixture. The mixture is then filtered to remove the precipitate, and then subjected to high-efficiency catalytic oxidation to remove the benzene and chlorobenzene. When treating high-concentration or supersaturated chlorobenzene wastewater with high-efficiency catalytic oxidation, the density of chlorobenzene is slightly greater than that of water, resulting in both the pre-precipitate and the precipitated water containing a chlorobenzene liquid phase. This makes it difficult to separate the precipitate from the water, which is environmentally friendly. Furthermore, the high chlorobenzene concentration and chlorobenzene droplets during the high-efficiency catalytic oxidation process prevent the wastewater from being completely inorganically harmless, resulting in poor treatment results, unstable operation control, and difficulty meeting standards, which is still harmful to the environment.

[0006] Chinese invention patent CN 105565416 A discloses a method for treating wastewater from a chlorobenzene plant. Specifically, it involves pre-treating the wastewater using a metal-loaded activated carbon adsorption treatment unit. The activated carbon is modified and used for adsorption treatment of the wastewater at low temperatures. The adsorbent is then desorbed at high temperatures using low-pressure steam and nitrogen to recover benzene and chlorobenzenes. The desorbed adsorbent is reusable. The treated chlorobenzene wastewater contains less than 100 ppm of both benzene and chlorobenzene, and the organic matter removal rate exceeds 90%, conserving resources and reducing the cost of biochemical wastewater treatment. In the examples, the treatment process involves treating chlorobenzene at a concentration of 200 to 300 mg / L. The post-treatment chlorobenzene concentration is less than 100 mg / L, which does not completely eliminate the toxicity of the chlorobenzene and requires steam regeneration of the activated carbon.

[0007] In summary, the current treatment process of chlorobenzene-containing wastewater, especially supersaturated chlorobenzene wastewater, has the following technical problems:

[0008] 1. Due to the presence of chlorobenzene liquid phase, it is difficult to use the existing process to discharge harmlessly and meet the standards. When it is disposed of as a hazardous waste, the treatment cost is high.

[0009] 2. When wastewater is treated with advanced oxidation, once supersaturated chlorobenzene precipitates, it will cause a persistent and slow release in the treatment facility, resulting in reduced treatment effect and difficulty in operation control.

[0010] 3. The intermediate products of chlorobenzene oxidation are dark in color and still have high environmental toxicity. High concentrations of chlorobenzene wastewater lead to a significant decrease in the efficiency of UV oxidation, prolonged oxidation time, and increased operating costs. When the oxidation is not complete, it is still harmful to the environment.

[0011] 4. The sediment from the pretreatment process contains chlorobenzene, which makes it difficult to separate the sediment from the water in an environmentally friendly manner, causing serious pollution to the environment and posing health risks to the processing personnel.

[0012] 5. The use of modified activated carbon to adsorb chlorobenzene has the problem of incomplete removal of pollutants and high regeneration cost.

[0013] Therefore, it is necessary to develop a treatment method and device that is environmentally friendly and can efficiently and thoroughly remove organic matter from supersaturated chlorobenzene wastewater. Summary of the Invention

[0014] The present invention provides a method and apparatus for treating supersaturated wastewater containing chlorobenzenes, addressing existing issues such as high chlorobenzene concentrations, difficulty in treatment, and unstable operation of treatment facilities in supersaturated chlorobenzene wastewater treatment processes. The present invention provides an environmentally friendly treatment process that efficiently and thoroughly removes organic matter from supersaturated chlorobenzene wastewater. The present invention is applicable to processes for treating high-concentration / supersaturated chlorobenzene-containing organic wastewater and high-concentration / supersaturated chlorobenzene-containing organic wastewater, as well as other high-concentration organic wastewater and supersaturated other organic wastewater.

[0015] The technical solution of the present invention is:

[0016] In a first aspect, a method for treating supersaturated chlorobenzene-containing organic wastewater is disclosed, comprising the following steps:

[0017] 1) Separation and dissolution of undissolved chlorobenzene: Supersaturated chlorobenzene-containing organic wastewater enters the primary reaction tower under the pressure of the pipeline or the lifting of a water pump, and mixes with the effluent of the primary reaction tower to form mixed wastewater. The mixed wastewater passes through the packing layer from bottom to top in the reaction tower, and undissolved chlorobenzene is intercepted by the packing;

[0018] 2) Chlorobenzene oxidation and packing regeneration: Acid, oxidant 1, and catalyst are added to the mixed wastewater flowing out of the top of the primary reaction tower. The mixed wastewater is then pumped into the primary UV reactor for oxidation and then into the packing layer of the primary reaction tower for regeneration. The mixed wastewater 2 in the effluent of the primary reaction tower is refluxed to continue dissolving chlorobenzene. The mixed wastewater 3 is pumped into the secondary UV reactor.

[0019] 3) Complete oxidation of chlorobenzene and its intermediates: Add oxidant 2 to the mixed waste liquid 3 lifted by the water pump, then mix it with the circulating water from the secondary reactor lifted by the circulating water pump, enter the secondary UV reactor, return to the secondary reactor for recycling and degradation, and after cyclic degradation, form mixed waste liquid 4 that overflows out of the secondary reactor;

[0020] 4) Flocculation and sedimentation: add alkali solution and coagulant aid to the mixed waste liquid No. 4, and treat the mixed waste liquid No. 4 by flocculation and sedimentation before it meets the discharge standards.

[0021] The water pump is an acid and alkali resistant water pump and is selected according to conventional design.

[0022] Preferably, the primary reaction tower and the secondary reaction kettle are made of one of polytetrafluoroethylene, polyethylene or enamel; based on the influent water, the hydraulic retention time of the primary reaction tower is 1.0-3.0h, and the hydraulic retention time of the secondary reaction kettle is 3.0-6.0h.

[0023] Preferably, the first oxidant is a hydrogen peroxide solution, the dosage of which is 1000-2000 mg / L as pure hydrogen peroxide, and the concentration of the effluent from the primary reaction tower is 500-1500 mg / L as pure hydrogen peroxide; the second oxidant is ozone, persulfate or hydrogen peroxide solution, preferably hydrogen peroxide solution, and the dosage of which is 50-500 mg / L as pure oxidant two.

[0024] Preferably, the catalyst is a ferric salt or a divalent iron salt, and the total iron concentration in the primary reaction tower is 50-100 mg / L; the acid solution is sulfuric acid or hydrochloric acid, and the alkali solution is sodium hydroxide or potassium hydroxide.

[0025] Preferably, the reaction temperature of the primary reaction tower is 60-65° C., and the reaction pH value of the primary reaction tower is 2.0-2.5; the reaction temperature of the secondary reactor is 45-55° C., and the reaction pH value of the secondary reactor is 2.5-3.0.

[0026] Preferably, the primary reaction tower is provided with a filler, which is one of granular activated carbon, columnar activated carbon or activated carbon fiber. The hydraulic retention time of the filler layer is 0.5 to 2.0 h based on the influent water.

[0027] Preferably, the total effluent flow rate from the primary reaction tower is 2-5 times the inlet flow rate, the effluent flow rate to the secondary UV reactor is the same as the inlet flow rate, and the rest goes to the primary UV reactor; the effluent flow rate from the secondary reactor is 3-10 times the inlet flow rate.

[0028] Preferably, the UV lamp of the primary UV reactor is a lamp with a wavelength of 200-400nm, preferably a medium pressure UV lamp, and preferably has an installed power of 2000-3000W / m 3 The UV lamp of the secondary UV reactor is a lamp with a wavelength of 200-400nm, preferably a medium pressure UV lamp, preferably with an installed power of 500-2000W / m 3 .

[0029] Preferably, the pH value of the flocculation sedimentation tank is 7-9, the coagulant is polyacrylamide, the addition concentration is 1-10 mg / L, and the hydraulic retention time is 2-4 h.

[0030] In a second aspect, the supersaturated chlorobenzene-containing organic wastewater treatment device is disclosed, comprising a primary reaction tower, a secondary reactor and a flocculation sedimentation tank connected in sequence by pipelines, a packing layer is arranged in the primary reaction tower, the primary reaction tower is provided with a wastewater inlet pipeline, a primary reaction tower outlet pipeline, the primary reaction tower outlet pipeline is provided with an acid feed pipeline, an oxidant 1 or catalyst feed pipeline and a primary UV reactor; an alkali solution inlet pipeline 1, an oxidant 2 inlet pipeline and a secondary UV reactor are provided on the pipeline between the primary reaction tower and the secondary reactor, an alkali solution inlet pipeline 2 is provided on the pipeline between the secondary reactor and the flocculation sedimentation tank, the secondary reactor is also provided with a return water pipeline, and the flocculation sedimentation tank is provided with a treated wastewater outlet pipeline.

[0031] The specific working process is as follows: supersaturated chlorobenzene wastewater as influent first enters the primary reaction tower under the pressure of the pipeline or the lifting action of a water pump. A packing layer is set in the primary reaction tower. After the influent and the effluent from the primary reactor are mixed in the lower space of the packing layer, they flow through the packing layer from bottom to top. The undissolved chlorobenzene liquid phase in the influent is blocked by the packing in the lower area of ​​the packing, and the wastewater phase enters the packing layer. In the packing layer, the packing absorbs the dissolved chlorobenzene in the influent and the oxidant, oxidative free radicals and chlorobenzene intermediates in the effluent from the primary UV reactor, and conducts adsorption, oxidation and decomposition in the pores of the packing. Part of the effluent from the primary reaction tower packing (mixed waste liquid 2) is lifted by a water pump and added with acid, oxidant 1 and catalyst, and then returns to the primary UV reactor for circulation. Part of the effluent (mixed waste liquid 3) is lifted by a water pump and added with alkali solution and oxidant 2, and then enters the secondary UV reactor. By controlling the relatively acidic environment within the primary reaction tower, the oxidant and catalyst undergo synergistic catalytic oxidation under the action of the primary UV reactor, producing high-concentration, highly oxidizing hydroxyl radicals. Acid, oxidant, and catalyst are added to the effluent from the primary reaction tower's packing (mixed waste liquid II) before returning to the circulation pipeline of the primary UV reactor. A certain oxidant concentration is maintained, especially within the packing layer of the primary reaction tower, to effectively degrade organic compounds such as chlorobenzene. The effluent from the packing layer does not contain undissolved chlorobenzene. An appropriate amount of alkaline solution is added to the effluent entering the secondary UV reactor to reduce the acidic environment. The effluent is then mixed with the effluent from the secondary reactor's circulating pump. Synergistic catalytic oxidation occurs under the action of oxidant II, the residual catalyst in the effluent mixed waste liquid III (mixed waste liquid III contains a catalyst derived from the catalyst added to mixed waste liquid II), and the secondary UV reactor, producing high-concentration hydroxyl radicals again. Chlorobenzene and other organic compounds are cyclically oxidized within the secondary reactor until they are relatively completely inorganicized. After the effluent from the secondary reactor is adjusted to neutral by adding alkaline solution, coagulant is added to the flocculation sedimentation tank to achieve mud-water separation, and the supernatant is discharged as effluent.

[0032] The present invention realizes the wastewater treatment process by jointly completing the synergistic effect of a primary reaction tower and a primary UV reactor, and the synergistic effect of a secondary reaction tower and a secondary UV reactor. The working principle is as follows: after undissolved chlorobenzene in the influent is intercepted by the filler layer, the chlorobenzene in the influent water phase and the effluent of the first-stage reactor is oxidized by hydroxyl radicals in the water. The chlorobenzene is rapidly oxidized by the hydroxyl radicals into chlorophenols, an intermediate product with good water solubility, thereby significantly reducing the chlorobenzene concentration. However, the chlorophenols cause the chromaticity of the wastewater to increase. On the one hand, the filler of the present invention participates in the adsorption and oxidation process, so that chlorobenzene and its oxidation intermediates are adsorbed and oxidized. In the effluent of the upper layer of the filler, the chromaticity generated by the chlorobenzene intermediates is greatly reduced, thereby improving the catalytic efficiency of ultraviolet light in the first-stage UV reactor and the second-stage UV reactor. On the other hand, the filler intercepts the undissolved liquid phase of chlorobenzene. Due to the generation of chlorophenols, the chlorobenzene concentration decreases, and the chlorobenzene intercepted in the lower layer of the filler continues to dissolve. Due to the interception effect of the filler and the characteristic that the density of chlorobenzene is greater than that of water, a certain reaction temperature is controlled, and the chlorobenzene liquid droplets are divided and crushed by the filler, thereby accelerating the dissolution process of chlorobenzene and ensuring the re-dissolution of the chlorobenzene liquid phase in the supersaturated chlorobenzene wastewater. The effluent from the primary reaction tower no longer contains chlorobenzene liquid phase, but is a homogeneous wastewater. A portion of the effluent from the primary reaction tower circulates into the primary UV reactor to continue dissolving the chlorobenzene liquid phase in the influent, and the other portion enters the secondary UV reactor. The remaining newly added oxidant 2, residual oxidant 1 and catalyst in the effluent continue to undergo deep catalytic oxidation. During the cyclic oxidation process in the secondary oxidation reactor, chlorobenzene and intermediate products are completely converted into carbon dioxide and water. After the pH value of the effluent from the secondary reactor is adjusted, the added catalyst is converted into a flocculant in the flocculation sedimentation tank to produce an efficient precipitation effect, and insoluble substances are continued to be removed, and the effluent meets the direct discharge standard. The filler in the primary reaction tower is in a dynamic process of adsorption and oxidation regeneration of adsorbed free radicals. Under the reaction temperature conditions of the present invention, the filler does not need to be regenerated offline.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The problem of a significant decrease in the efficiency of ultraviolet catalytic oxidation due to the color of the chlorobenzene intermediate product during the treatment of high-concentration chlorobenzene wastewater was solved through filler adsorption oxidation.

[0035] (2) Based on the efficient oxidation of chlorobenzene by ultraviolet catalytic oxidation, the gradual dissolution of the chlorobenzene liquid phase was achieved by utilizing the area under the packing. The turbulent flow disturbance of the water flow under the packing and the blocking effect of the packing both promoted the continued dissolution of chlorobenzene.

[0036] (3) The UV reactor is used to increase the water temperature and control the reaction temperature, ensuring that chlorobenzene is efficiently dissolved while the dissolved chlorobenzene is no longer saturated and precipitated, thereby promoting the effect of ultraviolet catalytic oxidation.

[0037] (4) Under the pH value environment and temperature parameters of the primary reaction tower, the process of adsorption and oxidation of chlorobenzene by the filler is ensured to proceed smoothly. At the same time, the oxidative free radicals have an adsorption and regeneration effect on the filler, ensuring that the filler continues to function efficiently and the filler does not need to be regenerated offline.

[0038] (5) The environmentally friendly treatment of the chlorobenzene liquid phase in the supersaturated chlorobenzene wastewater was achieved. Compared with the outsourcing of hazardous waste disposal, the operating cost is lower, it is harmless to the environment, and meets the requirements of the green development of the enterprise.

[0039] (6) The present invention solves the problem that the existing process for supersaturated chlorobenzene wastewater cannot be effectively treated under normal circumstances and can only be treated as hazardous waste. The treatment process of the present invention is more green and environmentally friendly.

[0040] (7) During the oxidation process, chlorobenzene is first oxidized into toxic intermediates such as chlorophenol, hydroquinone, and quinone. Due to the presence of the chlorobenzene liquid phase, the supersaturated wastewater dissolves and reacts simultaneously. As a result, chlorobenzene and the intermediates cannot be completely rendered harmless in the same reaction system, reducing the oxidation efficiency and making it difficult for the effluent to meet the standards. The present invention uses fillers in the primary reaction tower to solve the problem of separating the chlorobenzene liquid phase from water, efficiently converting chlorobenzene into intermediates while promoting the continued dissolution of chlorobenzene. In the secondary reactor, there is no chlorobenzene liquid phase, only homogeneous wastewater. The chlorobenzene and intermediates dissolved in the water can be efficiently oxidized, completely achieving harmless wastewater discharge that meets standards.

[0041] (8) The filler of the present invention has the function of intercepting and separating the aqueous phase and the chlorobenzene liquid phase in the wastewater, and also has the function of adsorbing dissolved organic matter, free radicals, and oxidants in the water, creating conditions for adsorption and oxidation. Under the preferred process conditions, the organic matter, free radicals, and oxidants adsorbed in the pores of the filler have a higher probability of collision oxidation. After the organic matter is oxidized, the pores of the filler are released, realizing the self-circulation of filler adsorption-regeneration-adsorption. The filler does not need to set up an offline regeneration process, solving the problem of using activated carbon to adsorb chlorobenzene in the prior art and requiring offline regeneration using steam or nitrogen. In addition, the adsorption of organic matter by the filler also reduces the color of the wastewater, ensuring the efficient treatment of chlorobenzene in the circulation process of the first reaction tower and improving the oxidation efficiency. The color of the wastewater going to the secondary reactor is also greatly reduced, creating conditions for the complete oxidation and harmless treatment of the secondary reactor.

[0042] (9) The synergistic effect of the primary reaction tower and the secondary reactor: the primary reaction tower controls the oxidation process by operating conditions to mainly convert chlorobenzene into intermediate products, and the secondary reactor controls the operating conditions to mainly completely oxidize chlorobenzene, chlorobenzene intermediates and other organic substances, thereby solving the problems of unstable operation caused by the chlorobenzene liquid phase, difficult to control the treatment process, and incomplete oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1It is a structural schematic diagram of the present invention.

[0044] In the figure, 1. primary reaction tower; 101. packing layer; 102. wastewater inlet pipeline; 103. primary reaction tower outlet pipeline; 104. acid feed pipeline; 105. oxidant 1 or catalyst feed pipeline; 2. secondary reactor; 3. flocculation sedimentation tank; 4. primary UV reactor; 5. alkali solution inlet pipeline 1; 6. oxidant 2 inlet pipeline; 7. secondary UV reactor; 8. alkali solution inlet pipeline 2; 9. return water pipeline; 10. treated wastewater outlet pipeline. DETAILED DESCRIPTION

[0045] The examples all adopt the method and device for recycling supersaturated chlorobenzene-containing wastewater of the present invention, and further illustrate the beneficial effects of the present invention.

[0046] The present invention provides a device for treating supersaturated chlorobenzene-containing organic wastewater, comprising a primary reaction tower 1, a secondary reactor 2, and a flocculation sedimentation tank 3, which are sequentially connected by pipelines. A packing layer 101 is provided in the primary reaction tower 1, and the primary reaction tower 1 is provided with a wastewater inlet pipeline 102 and a primary reaction tower outlet pipeline 103. The primary reaction tower outlet pipeline 103 is provided with an acid feed pipeline 104, an oxidant first or catalyst feed pipeline 105, and a primary UV reactor 4; an alkali solution inlet pipeline 1 5, an oxidant second inlet pipeline 6, and a secondary UV reactor 7 are provided on the pipeline between the primary reaction tower 1 and the secondary reactor 2; an alkali solution inlet pipeline 2 8 is provided on the pipeline between the secondary reactor 2 and the flocculation sedimentation tank 3; the secondary reactor 2 is further provided with a return water pipeline 9; and the flocculation sedimentation tank 3 is provided with a treated wastewater outlet pipeline 10.

[0047] It should be noted that the driving force for the water flow in the present invention is provided by a conventional water pump. If the pipeline pressure is insufficient, a water pump is required to pump water into the primary reaction tower 1. A water pump is also installed in the pipeline between the primary reaction tower 1 and the acid feed pipeline 104. A water pump is also installed in the pipeline between the primary reaction tower 1 and the alkali inlet pipeline 5. A circulating water pump is also installed in the return water pipeline 9 at the circulation outlet of the secondary reactor 2, before mixing the water discharged from the primary reaction tower 1 with the alkali solution.

[0048] The method for treating supersaturated chlorobenzene-containing organic wastewater comprises the following steps:

[0049] 1) Separation and Dissolution of Undissolved Chlorobenzene: Supersaturated chlorobenzene-containing organic wastewater enters primary reaction tower 1 along wastewater inlet pipe 102, where it mixes with the effluent from primary reaction tower outlet pipe 103 to form mixed wastewater. This mixed wastewater then flows upward through packing layer 101 within the reaction tower, where undissolved chlorobenzene is intercepted by the packing. Furthermore, due to the low chlorobenzene concentration in the effluent from primary UV reactor 4, the temperature conditions in the lower layer of packing allow for continued efficient dissolution and interception of chlorobenzene. It should be noted that during initial operation of the device, the effluent from primary reaction tower outlet pipe 103 serves as the startup water or reaction water reserved for primary reaction tower 1.

[0050] 2) Oxidation of chlorobenzene and regeneration of packing: Acid, oxidant 1 and catalyst are added to the mixed wastewater flowing out from the top of the primary reaction tower 1. At a certain temperature, the chlorobenzene in the wastewater is in an oxidative excited state after photolysis after being irradiated by high-intensity ultraviolet light. At the same time, oxidant 1 is catalytically decomposed by high-intensity ultraviolet light to produce hydroxyl free radicals and native oxygen, which effectively oxidizes chlorobenzene and reduces the concentration of chlorobenzene in the wastewater. Then, after oxidation in the primary UV reactor, it enters the packing layer of the primary reaction tower 1 for regeneration of the packing layer. After the effluent from the primary UV reactor leaves the catalytic action of the ultraviolet light, the oxidant 1 in the effluent reacts with the strong oxidizing free radicals. The organic matter in the wastewater is continuously degraded efficiently and enters the packing layer. The packing simultaneously adsorbs chlorobenzene and the colored chlorobenzene oxidation intermediates, as well as hydroxyl radicals and native oxygen, increasing the contact probability between the organic matter and the oxidizing free radicals and improving the oxidation effect. After being adsorbed, the organic matter is decomposed by the free radicals, realizing the dynamic regeneration of the packing. The mixed waste liquid in the effluent of the primary reaction tower is refluxed for further dissolving chlorobenzene, and the mixed waste liquid is sent to the secondary UV reactor. The temperature control of this process is to achieve efficient dissolution of chlorobenzene in step 1) and dynamic regeneration of the packing, while taking into account the oxidation efficiency.

[0051] 3) Complete oxidation of chlorobenzene and its intermediates: The effluent mixed waste liquid 3 from the primary reaction tower 1 no longer contains a chlorobenzene liquid phase. The remaining oxidant 1 and catalyst in the water are adjusted to acidity and temperature conditions more suitable for advanced oxidation, and then the oxidant 2 is added to the mixed waste liquid 3. The mixed waste liquid 3 is circulated and degraded in the secondary UV reactor 7 and the secondary reactor 2, thereby achieving efficient and complete oxidation of chlorobenzene and other organic matter in the wastewater. After cyclic degradation, the mixed waste liquid 4 is formed and flows out of the secondary reactor 2;

[0052] 4) Flocculation and sedimentation: add alkali solution and coagulant to the mixed waste liquid No. 4. The catalyst has both catalytic and flocculating effects. The catalyst is iron salt, which acts as a catalyst under acidic conditions, ultraviolet light and hydrogen peroxide. When the pH value is adjusted to 7-9, the iron ions have a flocculating effect. The coagulant is added as an auxiliary. The mixed waste liquid No. 4 is flocculated and sedimented before it meets the discharge standards.

[0053] The materials of the primary reaction tower 1 and the secondary reactor 2 are both made of polytetrafluoroethylene, polyethylene, or enamel. The material used in the embodiments and comparative examples is carbon steel lined with anti-corrosion material enamel; based on the water inlet, the hydraulic retention time of the primary reaction tower 1 is 1-3h, and the hydraulic retention time of the secondary reactor 2 is 3-6h.

[0054] The first oxidant is a hydrogen peroxide solution, the dosage of which is 1000-2000 mg / L as pure hydrogen peroxide, and the concentration of the effluent from the primary reaction tower 1 is 500-1500 mg / L as pure hydrogen peroxide; the second oxidant is ozone, persulfate or hydrogen peroxide solution, preferably hydrogen peroxide solution, and the dosage of which is 50-500 mg / L as pure oxidant 2.

[0055] The catalyst is a ferric salt or a divalent iron salt, and the total iron concentration in the primary reaction tower 1 is 50-100 mg / L; the acid solution is sulfuric acid or hydrochloric acid, and the alkali solution is sodium hydroxide or potassium hydroxide.

[0056] The reaction temperature of the primary reaction tower 1 is 60-65°C, the control method is ultraviolet power adjustment, and the reaction pH value of the primary reaction tower 1 is 2.0-2.5; the reaction temperature of the secondary reactor 2 is 45-55°C, the temperature control method is circulating water, and the reaction pH value of the secondary reactor 2 is 2.5-3.0.

[0057] The first-stage reaction tower 1 is provided with a filler, which is one of granular activated carbon, columnar activated carbon or activated carbon fiber. The hydraulic retention time of the filler layer is 0.5-2.0h based on the influent water.

[0058] The total outflow rate of the primary reaction tower 1 is 2-5 times the inflow rate, the outflow rate to the secondary UV reactor 7 is the same as the inflow rate, and the rest goes to the primary UV reactor 4; the outflow rate of the secondary reactor 2 is 3-10 times the inflow rate.

[0059] The primary UV reactor 4 and the secondary UV reactor 7 are both connected by a UV lamp, a reaction tube, and a controller. The UV lamp and the reaction tube are both electrically connected to the controller. The reaction tube is provided with a quartz sleeve and a sewage treatment tube. The quartz sleeve is used to isolate the UV lamp and the wastewater. The sewage treatment tube is made of quartz, polytetrafluoroethylene, or polyethylene. The volume of the sewage treatment tube is calculated based on a water residence time of 30-60 seconds. The primary UV reactor and the secondary UV reactor are both common commercially available structures. The UV lamp of the primary UV reactor 4 is a lamp with a wavelength of 200-400nm, preferably a medium-pressure UV lamp, and preferably has an installed power of 2000-3000W / m 3 Secondary UV reactor 7 of the ultraviolet lamp wavelength 200-400nm ultraviolet lamp, preferably medium pressure ultraviolet lamp, preferably installed power of 500-2000W / m 3 .

[0060] The pH value of the flocculation sedimentation tank 3 is 7-9, the coagulant is polyacrylamide, the addition concentration is 1-10 mg / L, and the hydraulic retention time is 2-4 h.

[0061] Example 1

[0062] The measured concentration of chlorobenzene in the wastewater of a chemical plant is 380-450 mg / L, and the COD is 500-600 mg / L. Visual observation shows that the bottom of the water sample contains a chlorobenzene liquid phase in the form of liquid droplets, which are separated from the aqueous phase. In this embodiment, the secondary reactor and the primary reaction tower are both made of carbon steel lined with enamel. The purpose of adding the reagent is to achieve the control parameters. The specific addition method adopts the conventional addition method, and the implementation process is not described in detail. The lamps installed in the primary UV reactor and the secondary UV reactor are both ultraviolet lamps that generate a wavelength of 200-400 nm.

[0063] The operating parameters are as follows:

[0064] The first oxidant is a hydrogen peroxide solution, and the dosage is 2000 mg / L in terms of pure hydrogen peroxide. The catalyst is a ferric chloride solution. The total iron concentration of the first-stage reaction tower 1 is controlled to be 100 mg / L, the hydraulic retention time is 2 hours, the reaction temperature is 64±1°C, and the reaction pH is adjusted to 2.2±0.1 by adding hydrochloric acid. Granular coconut shell activated carbon is selected as the packing layer 101, and the empty tower hydraulic retention time of the packing layer 101 is 1 hour. The total amount of water outlet from the first-stage reaction tower 1 is 5 times the water inlet flow rate, and the actual water outlet concentration of the first-stage reaction tower 1 is controlled to be 1500 mg / L in terms of pure hydrogen peroxide.

[0065] The UV power of the first-stage UV reactor 4 is 3000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 120S.

[0066] The second oxidant is hydrogen peroxide solution, the dosage is 500 mg / L based on pure hydrogen peroxide, the hydraulic retention time is 4 h, the reaction temperature is 53±2°C, the reaction pH value is 2.9±0.1, and the total amount of water outlet from the secondary reactor 2 is 5 times the inlet flow rate.

[0067] The UV power of the secondary UV reactor 7 is 1000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 60s.

[0068] Sodium hydroxide solution was added to flocculation sedimentation tank 3 to adjust the pH value to 8.5±0.5. The coagulant was cationic polyacrylamide with a concentration of 5 mg / L and a residence time of 3 h.

[0069] Run results:

[0070] The effluent chlorobenzene concentration of the primary reaction tower 1 is 20-100 mg / L, COD is 100-200 mg / L, and the color is yellow. The effluent chlorobenzene concentration of the flocculation sedimentation tank 3 is <0.1 mg / L, COD is 10-15 mg / L, turbidity is <2 NTU, SS (suspended solids) is 5-9 mg / L, and the color is colorless and transparent.

[0071] Example 2

[0072] The measured concentration of chlorobenzene in the wastewater from a rubber synthesis plant was 250-300 mg / L, and the COD was 200-400 mg / L. Visual observation revealed a chlorobenzene liquid phase at the bottom of the water sample, forming droplets that separated from the aqueous phase. In this embodiment, the secondary reactor was made of enamel, and the primary reactor was made of carbon steel lined with polytetrafluoroethylene. The purpose of adding the reagents was to achieve control parameters. Conventional dosing was used, and the implementation process will not be described in detail. The UV reactor was equipped with lamps that generated UV light with a wavelength of 200-400 nm. The operating parameters were as follows:

[0073] The first oxidant is a hydrogen peroxide solution, the dosage of which is 1000 mg / L in terms of pure hydrogen peroxide, the catalyst is a ferric chloride solution, the total iron concentration of the first-stage reaction tower 1 is controlled to be 50 mg / L, the hydraulic retention time is 1 hour, the reaction temperature is 61±1°C, hydrochloric acid is added to control the reaction pH value to be 2.4±0.1, granular coconut shell activated carbon is selected as the packing layer 101, the hydraulic retention time of the packing layer empty tower is 0.5 hour, the total amount of water outlet from the first-stage reaction tower 1 is twice the water inlet flow rate, and the actual water outlet concentration of the first-stage reaction tower 1 is controlled to be 500 mg / L in terms of pure hydrogen peroxide.

[0074] The UV power of the first-stage UV reactor 4 is 2000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 90s.

[0075] The second oxidant is hydrogen peroxide solution, the dosage is 200 mg / L based on pure hydrogen peroxide, the hydraulic retention time is 3 h, the reaction temperature is 47±2°C, the reaction pH value is 2.6±0.1, and the total amount of water outlet from the secondary reactor 2 is 10 times the inlet flow rate.

[0076] The UV power of the secondary UV reactor 7 is 1000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 30s.

[0077] Sodium hydroxide solution was added to flocculation sedimentation tank 3 to adjust the pH value to 7.5±0.5. The coagulant was cationic polyacrylamide with a concentration of 10 mg / L and a residence time of 4 h.

[0078] Run results:

[0079] The effluent chlorobenzene concentration of the primary reaction tower 1 is 30-80 mg / L, COD is 60-150 mg / L, and the color is yellow. The effluent chlorobenzene concentration of the flocculation sedimentation tank 3 is <0.1 mg / L, COD is 20-25 mg / L, turbidity is <1.5 NTU, SS is 6-10 mg / L, and the color is colorless and transparent.

[0080] Example 3

[0081] Wastewater from a chemical production was mixed with recycled reverse osmosis concentrate. The measured concentrations of dichlorobenzene in the water were 50-100 mg / L, acetone 30-50 mg / L, and COD 300-500 mg / L. Visual observation revealed a liquid phase at the bottom of the water sample, forming droplets that separated from the aqueous phase. In this embodiment, both the secondary reactor and the primary reactor were constructed of polyethylene. The purpose of adding the reagents was to achieve control parameters. Conventional dosing was used, and the implementation process will not be described in detail. The UV reactors were equipped with lamps that generated ultraviolet light at a wavelength of 200-400 nm. The operating parameters were as follows:

[0082] The first oxidant is a hydrogen peroxide solution, the dosage of which is 1500 mg / L in terms of pure hydrogen peroxide, the catalyst is a ferric chloride solution, the total iron concentration of the first-stage reaction tower 1 is controlled to be 80 mg / L, the hydraulic retention time is 3 hours, the reaction temperature is 62±1°C, sulfuric acid is added to control the reaction pH value to be 2.1±0.1, the packing layer 101 is granular coconut shell activated carbon, the hydraulic retention time of the packing layer empty tower is 2 hours, the total amount of water outlet from the first-stage reaction tower 1 is 3 times the water inlet flow rate, and the actual water outlet concentration of the first-stage reaction tower 1 is controlled to be 1000 mg / L in terms of pure hydrogen peroxide.

[0083] The UV power of the first-stage UV reactor 4 is 2500W / m 3 , the hydraulic retention time of the sewage treatment pipe is 60s.

[0084] The second oxidant is hydrogen peroxide solution, the dosage is 50 mg / L based on pure hydrogen peroxide, the hydraulic retention time is 6 h, the reaction temperature is 50±2°C, the reaction pH value is 2.8±0.1, and the total amount of water outlet from the secondary reactor 2 is 3 times the inlet flow rate.

[0085] The UV power of the secondary UV reactor 7 is 2000W / m 3 , the sewage treatment pipe has a hydraulic retention time of 45S.

[0086] Potassium hydroxide solution was added to flocculation sedimentation tank 3 to adjust the pH value to 8.0±0.5. The coagulant was anionic polyacrylamide with a concentration of 1 mg / L and a retention time of 2 hours. Operation results:

[0087] The effluent dichlorobenzene concentration of the primary reaction tower 1 is 1-5 mg / L, COD is 150-200 mg / L, and the color is light yellow. The effluent dichlorobenzene concentration of the flocculation sedimentation tank 3 is <0.1 mg / L, monochlorobenzene concentration is <0.1 mg / L, COD is 10-30 mg / L, turbidity is <3 NTU, SS is 10-15 mg / L, and the color is colorless and transparent.

[0088] The effects of the present invention are further described below with reference to the comparative example of Example 1.

[0089] Comparative Example 1

[0090] The measured concentration of chlorobenzene in the wastewater of a chemical plant is 380-450 mg / L, and the COD is 500-600 mg / L. Visual observation shows that the bottom of the water sample contains a chlorobenzene liquid phase in the form of liquid droplets that are separated from the aqueous phase. The method and device for recycling supersaturated chlorobenzene-containing wastewater of the present invention are used in the same operating mode, except that no packing layer is provided in the primary reaction tower 1, and the dosage of the oxidant 2 in the secondary reactor 2 is increased. The operating parameters are as follows:

[0091] The oxidant of the primary reaction tower 1 is hydrogen peroxide solution, and the dosage is 2000 mg / L based on pure hydrogen peroxide. The catalyst is ferric chloride solution, and the dosage concentration is 100 mg / L. The hydraulic retention time of the ferric chloride solution is 2 h, 64±1°C, and sulfuric acid is added to control the reaction pH value to 2.2±0.1. No packing layer is set. The total amount of water outlet from the primary reaction tower 1 is 5 times the water inlet flow rate. The actual hydrogen peroxide content in the water outlet from the primary reaction tower 1 is 1600 mg / L.

[0092] The UV power of the first-stage UV reactor 4 is 3000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 120S.

[0093] In the secondary reactor 2, the second oxidant is hydrogen peroxide solution, the dosage is 1000 mg / L based on pure hydrogen peroxide, the hydraulic retention time is 4 h, the reaction temperature is 53±2°C, the reaction pH value is 2.9±0.1, and the total amount of water outlet from the secondary reactor 2 is 5 times the inlet flow rate.

[0094] The UV power of the secondary UV reactor 7 is 1000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 60S.

[0095] Sodium hydroxide solution was added to flocculation sedimentation tank 3 to adjust the pH value to 8.5±0.5. The coagulant was cationic polyacrylamide with a concentration of 5 mg / L and a residence time of 3 h.

[0096] Run results:

[0097] The effluent chlorobenzene concentration of the primary reaction tower 1 is 200-400 mg / L, COD is 500-600 mg / L, and the color is reddish brown. The effluent chlorobenzene concentration of the flocculation sedimentation tank 3 is 20-50 mg / L, COD is 150-200 mg / L, turbidity is 50-100 NTU, and the color is yellowish brown.

[0098] Compared with Example 1, in Comparative Example 1, without the filler of the present invention, the primary effluent chlorobenzene and COD levels increased, and the color became darker. Even after increasing the oxidant dosage, the secondary effluent chlorobenzene and COD levels remained high, indicating that effective wastewater treatment was still not achieved and the direct discharge requirements of GB31571-2015 could not be met. The interception effect of the activated carbon filler in Example 1 promoted the effective degradation of the wastewater.

[0099] Comparative Example 2

[0100] The measured chlorobenzene concentration in wastewater from a chemical plant was 380-450 mg / L, and the COD was 500-600 mg / L. Visual observation revealed a chlorobenzene liquid phase at the bottom of the water sample, forming droplets that separated from the aqueous phase. The method and apparatus for reusing supersaturated chlorobenzene-containing wastewater of the present invention operated in essentially the same manner, except that the primary UV reactor 4 was stopped. The operating parameters for the remaining equipment were as follows:

[0101] The first oxidant is a hydrogen peroxide solution, and the dosage is 2000 mg / L based on pure hydrogen peroxide. The catalyst is a ferrous chloride solution. The total iron concentration of the first-stage reaction tower 1 is controlled to be 100 mg / L, the hydraulic retention time is 2 hours, the reaction temperature is 64±1°C, sulfuric acid is added to control the reaction pH value to be 2.2±0.1, granular coconut shell activated carbon is selected as the packing layer 101, the empty tower hydraulic retention time of the packing layer 101 is 1 hour, the total amount of water outlet from the first-stage reaction tower 1 is 5 times the inlet flow rate, and the actual water outlet concentration is 1500 mg / L based on pure hydrogen peroxide.

[0102] The UV power of the first-level UV reactor 4 is 0W / m 3 , the hydraulic retention time of the sewage treatment pipe is 120S.

[0103] The second oxidant is hydrogen peroxide solution, the dosage is 500 mg / L based on pure hydrogen peroxide, the hydraulic retention time is 4 h, the reaction temperature is 53±2°C, the reaction pH value is 2.9±0.1, and the total amount of water outlet from the secondary reactor 2 is 5 times the inlet flow rate.

[0104] The UV power of the secondary UV reactor 7 is 1000W / m 3 , the hydraulic retention time of the sewage treatment pipe is 60s.

[0105] Sodium hydroxide solution was added to flocculation sedimentation tank 3 to adjust the pH value to 8.5±0.5. The coagulant was cationic polyacrylamide with a concentration of 5 mg / L and a residence time of 3 h.

[0106] Run results:

[0107] The effluent from primary reactor 1 had a chlorobenzene concentration of 200-400 mg / L, COD of 450-550 mg / L, and a brown color. The effluent from flocculation sedimentation tank 3 had a chlorobenzene concentration of 50-100 mg / L, COD of 200-400 mg / L, turbidity of 50-100 NTU, and a dark brown color. After 24 hours of operation, the chlorobenzene concentration in the effluent from primary reactor 1 gradually increased, and chlorobenzene droplets were visible in the effluent.

[0108] Compared with Example 1, in Comparative Example 2, without the presence of the primary UV reactor 4 of the present invention, even though the catalyst was replaced with a ferrous salt, resulting in a Fenton oxidation effect, the primary effluent had high chlorobenzene and COD levels, darkened color, and subsequently, saturation of the activated carbon filler with adsorption occurred. Chlorobenzene droplets were visible in the effluent from the primary reaction tower 1, resulting in poor final effluent treatment. The primary UV reactor 4 generates a large number of strong oxidizing free radicals, which play a key role in promoting the dissolution of chlorobenzene and regenerating the activated carbon filler.

[0109] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions are intended to fall within the scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for treating supersaturated chlorobenzene-containing organic wastewater, characterized in that: The following steps are involved: 1) Separation and dissolution of undissolved chlorobenzene: The supersaturated chlorobenzene-containing organic wastewater enters the primary reaction tower (1) and is mixed with the effluent of the primary reaction tower (1) to form mixed wastewater. The mixed wastewater passes through the packing layer (101) from bottom to top in the reaction tower, and the undissolved chlorobenzene is intercepted by the packing; 2) Oxidation of chlorobenzene and regeneration of packing: Acid, oxidant 1 and catalyst are added to the mixed wastewater flowing out from the top of the primary reaction tower (1), and then the mixed wastewater is oxidized in the primary UV reactor (4) and then enters the packing layer (101) of the primary reaction tower (1) for regeneration of the packing layer (101). The mixed wastewater 2 in the effluent of the primary reaction tower (1) is refluxed to continue dissolving chlorobenzene, and the mixed wastewater 3 is sent to the secondary UV reactor (7); 3) Complete oxidation of chlorobenzene and its intermediates: adding oxidant 2 to mixed waste liquid 3, and the mixed waste liquid 3 is circulated and degraded in the secondary UV reactor (7) and the secondary reactor (2), and after cyclic degradation, mixed waste liquid 4 is formed and flows out of the secondary reactor (2); 4) Flocculation and sedimentation: add alkali liquor and coagulant to the mixed waste liquid No. 4, and treat the mixed waste liquid No. 4 by flocculation and sedimentation before it reaches the discharge standard; The first oxidant is a hydrogen peroxide solution; the second oxidant is one of ozone, persulfate or hydrogen peroxide solution.

2. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The primary reaction tower (1) and the secondary reaction kettle (2) are both made of one of polytetrafluoroethylene, polyethylene, or enamel; based on the influent water, the hydraulic retention time of the primary reaction tower (1) is 1-3 hours, and the hydraulic retention time of the secondary reaction kettle (2) is 3-6 hours.

3. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The dosage of the oxidant 1 is 1000-2000 mg / L in terms of pure hydrogen peroxide, and the concentration of the effluent from the upper part of the primary reaction tower (1) is 500-1500 mg / L in terms of pure hydrogen peroxide; the dosage of the oxidant 2 is 50-500 mg / L in terms of pure oxidant 2, and the oxidant 2 is a hydrogen peroxide solution.

4. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The catalyst is a ferric salt or a divalent iron salt, and the total iron concentration of the first-stage reaction tower (1) is 50-100 mg / L; the acid solution is sulfuric acid or hydrochloric acid, and the alkali solution is sodium hydroxide or potassium hydroxide.

5. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The reaction temperature of the primary reaction tower (1) is 60-65°C, and the reaction pH value of the primary reaction tower (1) is 2.0-2.5; the reaction temperature of the secondary reaction kettle (2) is 45-55°C, and the reaction pH value of the secondary reaction kettle (2) is 2.5-3.

0.

6. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The first-stage reaction tower (1) is provided with a packing layer (101), wherein the packing is one of granular activated carbon, columnar activated carbon or activated carbon fiber. The empty tower hydraulic retention time of the packing layer (101) is 0.5-2.0h based on the influent water.

7. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The total outflow rate of the primary reaction tower (1) is 2-5 times the inflow rate, the outflow rate to the secondary UV reactor (7) is the same as the inflow rate, and the remainder goes to the primary UV reactor (4); the outflow rate of the secondary reactor (2) is 3-10 times the inflow rate.

8. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The ultraviolet lamp of the first-stage UV reactor (4) is a lamp for ultraviolet light with a wavelength of 200-400 nm; the ultraviolet lamp of the second-stage UV reactor (7) is a lamp for ultraviolet light with a wavelength of 200-400 nm.

9. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 8, wherein: The UV lamp of the first-stage UV reactor (4) is a medium-pressure UV lamp with an installed power of 2000-3000W / m 3 The UV lamp of the secondary UV reactor (7) is a medium pressure UV lamp with an installed power of 500-2000W / m 3 .

10. The method for treating supersaturated chlorobenzene-containing organic wastewater according to claim 1, wherein: The pH value of the flocculation sedimentation tank (3) is 7-9, the coagulant is polyacrylamide, the addition concentration is 1-10 mg / L, and the hydraulic retention time is 2-4 h.

11. The device for treating supersaturated chlorobenzene-containing organic wastewater according to any one of claims 1 to 10, characterized in that: The invention comprises a primary reaction tower (1), a secondary reaction kettle (2) and a flocculation sedimentation tank (3) connected in sequence through pipelines, wherein a packing layer (101) is provided in the primary reaction tower (1), a wastewater inlet pipeline (102) and a primary reaction tower outlet pipeline (103) are provided in the primary reaction tower (1), an acid feed pipeline (104), an oxidant 1 or catalyst feed pipeline (105) and a primary UV reactor (4) are provided on the primary reaction tower outlet pipeline (103); an alkali solution inlet pipeline 1 (5), an oxidant 2 inlet pipeline (6) and a secondary UV reactor (7) are provided on the pipeline between the primary reaction tower (1) and the secondary reaction kettle (2); an alkali solution inlet pipeline 2 (8) is provided on the pipeline between the secondary reaction kettle (2) and the flocculation sedimentation tank (3); the secondary reaction kettle (2) is further provided with a return water pipeline (9); and the flocculation sedimentation tank (3) is provided with a treated wastewater outlet pipeline (10).

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