Advanced oxidation treatment process and device for wastewater

Abstract

The invention discloses a wastewater advanced oxidation treatment process and device and belongs to the technical field of wastewater treatment. Comprising the following steps: carrying out homogenization treatment on wastewater; effluent enters a first reaction tank to be filtered; the filtered effluent enters a first cavity of a UV reactor to be subjected to UV photooxidation treatment; water discharged from the first cavity enters a second cavity of the UV reactor, and is subjected to UV photocatalytic oxidation treatment in an acidic environment; effluent of the second cavity enters an oxidation circulation area at the lower part of the second reaction tank, one part of wastewater is discharged through a circulation outlet of the oxidation circulation area and enters the second cavity of the UV reactor again for circulation photocatalytic oxidation treatment, and the other part of wastewater enters an activated carbon filler area of the second reaction tank from bottom to top and is discharged from an outlet of the second reaction tank; the effluent enters a flocculation sedimentation tank for flocculation sedimentation treatment, and the treated effluent can be discharged. The process efficiently utilizes the effects of different wave bands of medium-pressure ultraviolet in water treatment, and has the characteristics of high oxidation efficiency, strong oxidation capacity and full utilization of ultraviolet light energy.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, and specifically relates to a wastewater advanced oxidation treatment process and device. Background Art

[0002] As the country attaches more importance to the protection of water resources, especially the Yangtze River and the Yellow River basins, the requirements for sewage discharged into the main streams of rivers are becoming more and more stringent. The use of biological treatment alone for enterprise wastewater often cannot meet the new discharge requirements, especially for difficult-to-biodegrade wastewater represented by reused concentrated water. Advanced Oxidation Process (AOPs) can directly mineralize organic matter in water that is difficult to biodegrade or improve the biodegradability of pollutants through oxidation, and has been increasingly used in recent years.

[0003] Photochemical and photocatalytic oxidation processes are the most studied advanced oxidation processes. Photochemical reactions require molecules to absorb light waves of a specific wavelength. The energy of photons causes the molecules to be excited, and then chemical reactions will occur to generate new substances, or become intermediate products that trigger subsequent reactions, achieving the effect of initial oxidation chain breaking. Ultraviolet light with oxidizing effects generally has a shorter wavelength, such as 185nm, and has weak penetration and is easily disturbed. Photocatalytic oxidation technology uses light, mainly ultraviolet light to excite and oxidize O 2 , H 2 O 2 When oxidants such as chlorinated bicarbonate are combined with light radiation, there is a synergistic effect between ultraviolet light and iron ions in the Fenton system, which makes H 2 O 2 The rate of decomposition to produce hydroxyl radicals is greatly accelerated, promoting the oxidation and removal of organic matter. At this time, 254nm ultraviolet light is mainly used for catalytic reaction.

[0004] In practical applications, the photocatalytic oxidation process is often not ideal for the degradation of organic matter due to the limitations of reaction conditions and equipment. For example, commonly used ultraviolet lamps are mainly low-pressure lamps and medium-pressure lamps. The wavelength of ultraviolet light generated by low-pressure lamps is relatively fixed, mainly generating ultraviolet light with a wavelength of 185nm and 254nm, which can be used for targeted photooxidation or photocatalytic oxidation. However, low-pressure lamps generally have low power. In engineering design, the number of lamps designed is often large, the equipment is large, and the implementation is difficult. There is also a high failure rate. Medium-pressure lamps have relatively large power and can generate ultraviolet light in a continuous band of 180-400nm. The equipment is small in size and easy to implement. The continuous wavelength region is more suitable for a variety of wastewaters and has attracted much attention in recent years. Due to the characteristics of the wavelength region of medium-pressure UV lamps, photooxidation and catalytic oxidation are carried out simultaneously during the reaction process. In particular, the introduction of catalysts and oxidants or Fenton systems promotes photocatalytic performance. At the same time, light irradiation is affected by chromaticity, turbidity, microbubbles, etc., and the oxidation chain breaking performance of light is disturbed, reducing the photolysis effect of UV light on chemical bonds. How to effectively play the advantages of medium-pressure UV has become the focus of further improving the efficiency of photocatalytic oxidation.

[0005] At present, in order to ensure a good oxidation effect, the amount of oxidant added is often large. The residual hydrogen peroxide in the effluent leads to high effluent COD, which must be removed by reduction, increasing the consumption of reducing agent. When the wastewater contains suspended matter, especially suspended matter that is difficult to remove by flocculation, such as tiny colloid particles in rubber wastewater and suspended matter in the water, it hinders the photolysis and catalytic effect of ultraviolet light, and a filter needs to be set up for treatment. The treatment of backwash water becomes a new problem to be solved. If the adsorption and filtration effect of activated carbon is used, the activated carbon often needs to be regenerated offline, and the energy consumption of steam regeneration is high.

[0006] Patent CN114538680A relates to a hydroxyl free radical-based difficult-to-degrade sewage treatment device, including a pretreatment box, a hydrogen peroxide storage tank, an ozone generator and a reaction chamber, the pretreatment box is connected to a sewage inlet pipe, an aeration pipe is arranged at the bottom of the pretreatment box, and a first air supply pipe is connected between the ozone generator and the aeration pipe; a water inlet pipe is connected between the pretreatment box and the lower part of the reaction chamber, and a water distribution pipe network connected to the water inlet pipe is arranged at the lower part of the reaction chamber; an ultraviolet lamp assembly is arranged in the middle of the reaction chamber; a water outlet is arranged on the upper side wall of the reaction chamber, a circulating water outlet is arranged on the top of the reaction chamber, a circulating water pipe is connected between the circulating water outlet and the water inlet pipe, and a hydrogen peroxide inlet pipe is connected between the circulating water pipe and the hydrogen peroxide storage tank. The invention uses ultraviolet rays and hydrogen peroxide to generate hydroxyl radicals for degrading organic pollutants, and ozone oxidation pretreatment is used to improve the transmittance of ultraviolet rays. There are problems that some organic matter cannot be decolorized and suspended matter cannot be effectively removed. At the same time, a multi-layer staggered distribution of ultraviolet lamps is used to increase the density of ultraviolet irradiation, so as to increase the number of hydroxyl radicals produced. However, the lamps are used in large quantities, have a high failure rate, and are complex to maintain. The two oxidants, ozone and hydrogen peroxide, need to work together.

[0007] Patent CN114702179A discloses a multi-dimensional catalytic organic wastewater treatment device, which is divided into a first reaction chamber, a second reaction chamber and a third reaction chamber inside the main body, forming a three-level or three-stage continuous catalytic reaction, and the upper area of ​​the three water treatment chambers forms an ultraviolet oxidation chamber; a titanium-based solid spherical catalyst is added to the first reaction chamber; ferrous sulfate and sodium percarbonate solution are added to the second reaction chamber; an air source ozone generator is configured in the third reaction chamber, and the invention superimposes multi-dimensional catalytic technologies such as photocatalysis, Fenton-like, photo-Fenton, chemical catalysis and ozone catalysis. The ultraviolet oxidation chamber is equipped with 15 ultraviolet lamps with a wavelength of 185 and 20 ultraviolet lamps with a wavelength of 254, and the lamps with a wavelength of 185 and 254 are arranged in a cross pattern, and light through holes are evenly distributed on the lower baffle of the ultraviolet oxidation chamber. This patent also has the problems of large consumption of ultraviolet lamps, high failure rate, and complex maintenance, and the existence of light through holes further reduces the utilization efficiency of ultraviolet light, which makes the efficiency of solid catalysts decrease, and the ultraviolet lamps have low power and single wavelength.

[0008] Patent CN112591846A discloses an MPUV advanced oxidation system for treating high-concentration, refractory organic wastewater, including a reaction tank, at least one group of photocatalytic reactors, a dosing system, a pipeline mixer and an online monitoring system. The photocatalytic reactor includes a medium-pressure ultraviolet lamp, a lamp sleeve, a reactor outer protection device and a ballast central control device. The reaction tank is connected to the water inlet end of the other end of the pipeline mixer, and the reactor outlet is also connected to the reflux pipeline and the outlet pipeline, and the reflux pipeline is connected to the reaction tank; it has a significant effect on the index control of COD or a single pollutant in sewage treatment. In the process of reducing COD, the biochemical property is further improved, which is convenient for subsequent biochemical treatment. This invention is a conventional medium-pressure ultraviolet catalytic oxidation. In order to ensure the oxidation effect, the circumferential width of the water flow channel between the lamp sleeve and the reactor shell is 1-2cm, which greatly reduces the utilization rate of the ultraviolet lamp. At the same time, the generation of bubbles in the reaction process reduces the effect of direct photolysis and oxidation of ultraviolet light.

[0009] In summary, most of the existing medium-pressure ultraviolet catalytic oxidation processes have the problems of low oxidation efficiency and inefficient use of energy in some bands of ultraviolet light. Summary of the invention

[0010] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a wastewater advanced oxidation treatment process and device, which efficiently utilizes the role of different bands of medium-pressure ultraviolet in water treatment and has the characteristics of high oxidation efficiency, strong oxidation ability and full utilization of ultraviolet light energy.

[0011] In order to achieve the above object, according to one aspect of the present invention, a wastewater advanced oxidation treatment process is provided, comprising the following steps: (1) Homogenization treatment: wastewater enters the homogenization tank for homogenization treatment; (2) Filtration and adsorption: The water from the homogenization tank enters the first reaction tank for filtration. The first reaction tank is provided with an activated carbon filling area and an oxidation circulation area from top to bottom; (3) UV light oxidation treatment: The filtered water enters the first chamber of the UV reactor for UV light oxidation treatment; (4) UV photocatalytic oxidation treatment: The water from the first chamber is mixed with the catalyst and oxidant and enters the second chamber of the UV reactor for UV photocatalytic oxidation treatment in an acidic environment; (5) Circular oxidation and regeneration: The effluent from the second chamber enters the oxidation circulation zone at the lower part of the second reaction tank. A portion of the wastewater is discharged through the circulation outlet of the oxidation circulation zone and enters the second chamber of the UV reactor again for cyclic photocatalytic oxidation treatment. The other portion of the wastewater enters the activated carbon filler zone at the upper part of the second reaction tank from bottom to top and is discharged from the second reaction tank outlet at the upper part of the second reaction tank. (6) Flocculation and sedimentation: The effluent from the outlet of the second reaction tank enters the flocculation sedimentation tank for flocculation and sedimentation treatment. After treatment, the effluent can be discharged.

[0012] In some embodiments, in step (1), the hydraulic retention time in the homogenization tank is 1-8 hours.

[0013] In some embodiments, in step (2), the hydraulic retention time in the first reaction tank is 1-6 hours, wherein the hydraulic retention time in the activated carbon filler zone is 0.2-2 hours, and the hydraulic retention time in the oxidation circulation zone is 0.8-4 hours.

[0014] In some embodiments, the UV reactor includes a reactor cavity, which is formed by being wrapped by a shell, a first quartz sleeve is arranged in the middle of the reactor cavity, an ultraviolet lamp is built in the first quartz sleeve, both ends of the ultraviolet lamp are connected to a power supply, a second quartz sleeve is arranged on the outside of the first quartz sleeve, the area between the first quartz sleeve and the second quartz sleeve is the first cavity, and the area between the second quartz sleeve and the shell is the second cavity; a first inlet is arranged at the lower part of the first cavity, and a first outlet is arranged at the upper part of the first cavity; a second inlet is arranged at the lower part of the second cavity, and a second outlet is arranged at the upper part of the second cavity; wherein, the distance between the inner wall of the second quartz sleeve and the outer wall of the first quartz sleeve is 40-140 mm, and the distance between the inner wall of the shell and the outer wall of the second quartz sleeve is 40-140 mm.

[0015] In some embodiments, the wavelength of the ultraviolet lamp is 180-400nm, and the installed power of the ultraviolet lamp is 200-2000W / m.

[0016] In some embodiments, the first reaction tank and the second reaction tank are both provided with a circulation inlet and a circulation outlet at the lower portion, the first reaction tank and the second reaction tank are both provided with a filtration inlet and a reaction tank outlet at the upper portion, and the first reaction tank and the second reaction tank are both provided with a filtration outlet at the bottom; the first reaction tank and the second reaction tank can be switched by a valve system on the pipeline.

[0017] In some embodiments, the hydraulic retention time of the first cavity and the second cavity is 60-120 seconds in total, and the outlet water temperature of the first cavity is 45-52°C.

[0018] In some embodiments, in step (4), the pH value of the UV photocatalytic oxidation treatment is 2.5-3.0; the catalyst includes at least one of a trivalent iron salt and a divalent iron salt aqueous solution; and the oxidant includes at least one of a hydrogen peroxide solution and ozone.

[0019] In some embodiments, in step (5), the hydraulic retention time in the second reaction tank is 1-6 hours, wherein the hydraulic retention time in the activated carbon filler zone is 0.2-2 hours, and the hydraulic retention time in the oxidation circulation zone is 0.8-4 hours; and the pH value in the second reaction tank is 2.5-3.0.

[0020] In some embodiments, in step (6), the flocculation sedimentation treatment is as follows: adjusting the pH value of the flocculation sedimentation tank to 7-9, adding a coagulant at a concentration of 5-15 mg / L, and the hydraulic retention time of the flocculation sedimentation tank is 1-3 h.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a wastewater advanced oxidation treatment process, which effectively utilizes the role of different bands of medium-pressure ultraviolet in water treatment, improves the utilization rate of ultraviolet light, and has the characteristics of high oxidation efficiency, strong oxidation capacity, and full utilization of ultraviolet light energy. By setting up two groups of reaction tanks, one group plays a filtering role while the other group plays an oxidation and backwashing regeneration role. The oxidant and catalyst in the effluent of the second cavity of the UV reactor have a regeneration effect on the activated carbon, the bubbles have a scrubbing and backwashing effect, and the oxidant and oxidative free radicals attack the surface of the suspended matter to destabilize and create conditions for subsequent flocculation and sedimentation. The above multiple synergistic effects not only complete the regeneration of the filler, but also eliminate the residual oxidant in the effluent, and there is no need to add a reducing agent to eliminate the oxidant.

[0022] (2) The present invention designs a UV reactor with a special structure, which includes a first cavity and a second cavity. High-energy ultraviolet light enters the second cavity through the first cavity, and short-wave ultraviolet photooxidation and photolysis occur in the first cavity. This process is not interfered by subsequent catalysts and oxidants, so that the photooxidation efficiency is improved; in the second cavity, ultraviolet light, catalysts and oxidants cooperate to catalyze oxidation. On the one hand, the photooxidation and photolysis of the first cavity make it easier for organic matter in the wastewater entering the second cavity to be catalytically oxidized; on the other hand, the water temperature of the water outlet from the first cavity increases, which further provides a suitable reaction temperature for the catalytic oxidation in the second cavity. The two together promote a higher reaction efficiency and a more thorough reaction of the catalytic oxidation reaction occurring in the second cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 This is a process flow chart of advanced oxidation treatment of wastewater according to an embodiment of the present invention. Figure 1In the figure, 1 is a homogenizing tank; 2 is the first reaction tank; 2-1 is the activated carbon filling area of ​​the first reaction tank; 2-2 is the oxidation circulation area of ​​the first reaction tank; 3 is the second reaction tank; 3-1 is the activated carbon filling area of ​​the second reaction tank; 3-2 is the oxidation circulation area of ​​the second reaction tank; 4 is the UV reactor; 4-7 is the first inlet; 4-8 is the first outlet; 4-9 is the second inlet; 4-10 is the second outlet; 5 is the flocculation sedimentation tank; 6 is the lifting pump; 7 is the filtering inlet of the first reaction tank; 8 is the outlet of the first reaction tank; 9 is the circulation outlet of the first reaction tank; 10 is the circulation inlet of the first reaction tank; 11 is the filtering outlet of the first reaction tank; 12 is the circulation pump; 13 is the circulation inlet of the second reaction tank; 14 is the circulation outlet of the second reaction tank; 15 is the filtering outlet of the second reaction tank; 16 is the filtering inlet of the second reaction tank; 17 is the outlet of the second reaction tank; 18 is the alkali solution and the coagulant aid dosing device; 19 is the sludge discharge; 20 is the water outlet.

[0024] Figure 2 This is the front view of the UV reactor in the embodiment of this application. Figure 2 In the figure, 4-1 is a shell; 4-2 is a first quartz sleeve; 4-3 is a second quartz sleeve; 4-4 is an ultraviolet lamp; 4-5 is a first cavity; 4-6 is a second cavity; 4-7 is a first inlet; 4-8 is a first outlet; 4-9 is a second inlet; 4-10 is a second outlet; and 4-11 is a wiring connection. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0026] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0027] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0028] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0029] The present invention provides a wastewater advanced oxidation treatment process, comprising the following steps: (1) Homogenization treatment: wastewater enters the homogenization tank for homogenization treatment; (2) Filtration and adsorption: The water from the homogenization tank enters the first reaction tank for filtration. The first reaction tank is provided with an activated carbon filling area and an oxidation circulation area from top to bottom; (3) UV light oxidation treatment: The filtered water enters the first chamber of the UV reactor for UV light oxidation treatment; (4) UV photocatalytic oxidation treatment: The water from the first chamber is mixed with the catalyst and oxidant and enters the second chamber of the UV reactor for UV photocatalytic oxidation treatment in an acidic environment; (5) Circular oxidation and regeneration: The effluent from the second chamber enters the oxidation circulation zone at the lower part of the second reaction tank. A portion of the wastewater is discharged through the circulation outlet of the oxidation circulation zone and enters the second chamber of the UV reactor again for cyclic photocatalytic oxidation treatment. The other portion of the wastewater enters the activated carbon filler zone at the upper part of the second reaction tank from bottom to top and is discharged from the second reaction tank outlet at the upper part of the second reaction tank. (6) Flocculation and sedimentation: The effluent from the outlet of the second reaction tank enters the flocculation sedimentation tank for flocculation and sedimentation treatment. After treatment, the effluent can be discharged.

[0030] According to the treatment method of the present invention, in some embodiments, in step (1), the hydraulic retention time in the homogenization tank is 1-8 hours. It can be understood that the hydraulic retention time can be any specific value of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours or any value within the range of 1-8 hours. Homogenization adjustment is a mixing process, the purpose of which is to balance the changes in water quality, water volume, etc. in view of the uneven distribution of wastewater discharge, so that the wastewater intake is evenly distributed. The present invention has no special restrictions on the homogenization tank, which can be a conventional homogenization tank in the art.

[0031] According to the treatment method of the present invention, in some embodiments, in step (2), the effluent from the homogenization tank enters the first reaction tank for filtration. Preferably, the effluent from the homogenization tank enters the first reaction tank through a lift pump, and the flow rate of the lift pump is used to control the hydraulic retention time of the first cavity and the second cavity of the UV reactor to be 60-120s in total. The first reaction tank is provided with an activated carbon filling area and an oxidation circulation area from top to bottom. In some embodiments, calculated based on the influent, the hydraulic retention time in the first reaction tank is 1-6h, wherein the hydraulic retention time in the activated carbon filling area is 0.2-2h, and the hydraulic retention time in the oxidation circulation area is 0.8-4h. The present invention has no specific restrictions on the material of the first reaction tank, and conventional reaction tank materials in the art can be used, including but not limited to polytetrafluoroethylene, polyethylene, etc.; in the present invention, the activated carbon filling area of ​​the first reaction tank is filled with activated carbon fillers. The present invention has no special restrictions on the activated carbon fillers in the activated carbon filling area in the first reaction tank, and conventional activated carbon fillers in the art can be used, including but not limited to granular, columnar activated carbon, etc. The activated carbon filler in the first reaction tank can filter and intercept the suspended matter in the wastewater, and at the same time adsorb some organic matter, reduce the chromaticity of the wastewater, and provide better conditions for subsequent UV oxidation. In the present invention, the oxidation circulation zone of the first reaction tank is a hollow cavity structure.

[0032] According to the processing method of the present invention, in some embodiments, the UV reactor includes a reactor cavity, the reactor cavity is formed by being wrapped by a shell, a first quartz sleeve is arranged in the middle of the reactor cavity, an ultraviolet lamp is built in the first quartz sleeve, both ends of the ultraviolet lamp are connected to a power supply, a second quartz sleeve is arranged on the outside of the first quartz sleeve, the area between the first quartz sleeve and the second quartz sleeve is the first cavity, and the area between the second quartz sleeve and the shell is the second cavity; a first inlet is arranged at the lower part of the first cavity, and a first outlet is arranged at the upper part of the first cavity; a second inlet is arranged at the lower part of the second cavity, and a second outlet is arranged at the upper part of the second cavity; wherein, the distance between the inner wall of the second quartz sleeve and the outer wall of the first quartz sleeve is 40-140 mm, and the distance between the inner wall of the shell and the outer wall of the second quartz sleeve is 40-140 mm.

[0033] According to the processing method of the present invention, in some embodiments, the material of the shell includes any one of 316 stainless steel and quartz glass; preferably, the stainless steel is a stainless steel material with an inner lining, and the inner lining can be an anti-corrosion coating or an anti-corrosion reflective coating.

[0034] According to the treatment method of the present invention, in some embodiments, the ultraviolet lamp has a wavelength of 180-400nm, and the installed power of the ultraviolet lamp is 200-2000W / m.

[0035] According to the treatment method of the present invention, in some embodiments, the material of the first quartz sleeve and the second quartz sleeve is ultraviolet high-transmittance quartz material, and the radius of the first quartz sleeve is suitable for installing the ultraviolet lamp tube to isolate the ultraviolet lamp tube and the wastewater medium.

[0036] In the present invention, in step (3), the filtered water enters the first cavity of the UV reactor for UV light oxidation treatment. In some embodiments, the outlet water temperature of the first cavity is 45-52°C. Specifically, in the present invention, the outlet water temperature of the first cavity can be adjusted by ultraviolet power. The present invention does not impose any restrictions on the pH value of UV light oxidation treatment in the first cavity. The inventors of the present invention have found that by designing a UV reactor with a special structure, in the first cavity, under the action of ultraviolet light passing through the first quartz sleeve, the organic matter in the wastewater is excited by the shorter wavelength ultraviolet light oxidation photolysis, resulting in a chain breaking effect. At the same time, the ultraviolet irradiation increases the water temperature. The reaction is not interfered by other factors (such as catalysts, oxidants), and the photooxidation efficiency is significantly improved, achieving efficient light energy utilization; in addition, the longer ultraviolet light with a suitable catalytic wavelength efficiently passes through the first cavity and enters the second cavity, creating conditions for the next step of catalytic oxidation.

[0037] In the present invention, in step (4), the effluent from the first cavity is mixed with the catalyst and the oxidant, and enters the second cavity of the UV reactor to perform UV photocatalytic oxidation treatment in an acidic environment. Preferably, the effluent from the first cavity is mixed with the catalyst and the oxidant, and enters the second inlet of the UV reactor through a circulation pump on the second inlet pipe of the UV reactor. In some embodiments, in step (4), the pH value of the UV photocatalytic oxidation treatment is 2.5-3.0. Preferably, the flow rate of the circulation pump is 2-9 times the flow rate of the booster pump.

[0038] According to the treatment method of the present invention, in some embodiments, the catalyst includes at least one of a trivalent iron salt and a divalent iron salt aqueous solution; further, the dosage of the catalyst is controlled according to the total iron concentration at the outlet of the circulating pump on the second inlet pipe of the UV reactor, and the total iron concentration at the outlet of the circulating pump on the second inlet pipe of the UV reactor is preferably controlled to be 50-100 mg / L.

[0039] According to the treatment method of the present invention, in some embodiments, the oxidant includes at least one of hydrogen peroxide solution and ozone; further, the mass ratio of the dry basis dosage of the oxidant to the influent COD is 3:1-10:1. It can be understood that the mass ratio can be any specific value of 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1 or any value within the range of 3:1-10:1. The dry basis dosage refers to the dosage calculated based on the absolute dry material, such as taking hydrogen peroxide solution as an example, the dosage calculated based on the conversion of the hydrogen peroxide solution into pure hydrogen peroxide.

[0040] In some specific embodiments, in step (4), the acidic environment of the second chamber can be adjusted by adding acid; more specifically, the acid can be added to the pipeline together with the catalyst and the oxidant. The present invention has no specific limitation on the type of the acid, and conventional acid in the art can be used, including but not limited to sulfuric acid, hydrochloric acid, etc.

[0041] In some specific embodiments, in step (4), the effluent from the first cavity is mixed with the catalyst and the oxidant and enters the second cavity of the UV reactor for UV photocatalytic oxidation treatment in an acidic environment. In the second cavity, the catalyst and the oxidant, under the action of ultraviolet light passing through the second quartz sleeve, produce hydroxyl free radicals with high oxidation performance in a suitable temperature and acidic environment, and efficiently oxidize and degrade the wastewater, especially the organic matter excited by the short-wave ultraviolet light passing through the first cavity, which is more easily oxidized and degraded. This step can give full play to the catalytic effect of ultraviolet light. Due to the addition of the oxidant and the catalyst, the oxidation reaction is violent, and the reaction produces a large number of bubbles, which provides conditions for the backwashing of the activated carbon filler in the next step.

[0042] In some embodiments of the present invention, the hydraulic retention time of the first cavity and the second cavity is 60-120s in total. The hydraulic retention time of the first cavity and the second cavity is allocated according to the distance between the inner wall of the second quartz sleeve and the outer wall of the first quartz sleeve, and the distance between the inner wall of the shell and the outer wall of the second quartz sleeve.

[0043] In some embodiments, in step (5), the effluent from the second cavity enters the oxidation circulation zone at the lower part of the second reaction tank, a portion of the wastewater is discharged through the circulation outlet of the oxidation circulation zone, and enters the second cavity of the UV reactor again for cyclic photocatalytic oxidation treatment, and another portion of the wastewater enters the activated carbon filler zone at the upper part of the second reaction tank from bottom to top, and is discharged from the second reaction tank outlet at the upper part of the second reaction tank. Among them, the ratio of the wastewater flow rate discharged through the circulation outlet to the wastewater flow rate at the filter inlet of the first reaction tank is 1:1-8:1, and the flow rate of the other portion of the wastewater is the same as the wastewater flow rate at the filter inlet of the first reaction tank. In some embodiments, in step (5), the hydraulic retention time in the second reaction tank is 1-6h calculated based on the influent, wherein the hydraulic retention time in the activated carbon filler zone is 0.2-2h, and the hydraulic retention time in the oxidation circulation zone is 0.8-4h. In some embodiments, in step (5), the pH value in the second reaction tank is 2.5-3.0. The present invention has no specific restrictions on the material of the second reaction tank, and conventional reaction tank materials in the field can be used, including but not limited to polytetrafluoroethylene, polyethylene, etc. In the present invention, the activated carbon filler area of ​​the second reaction tank is filled with activated carbon filler, and the present invention has no special restrictions on the activated carbon filler, and conventional activated carbon fillers in the art can be used, including but not limited to granular, columnar activated carbon, etc. In the present invention, the oxidation circulation area of ​​the second reaction tank is a hollow cavity structure.

[0044] In the present invention, in step (5), the effluent from the second cavity of the UV reactor enters the oxidation circulation zone at the lower part of the second reaction tank, and a part of the wastewater is discharged through the circulation outlet of the oxidation circulation zone and enters the second cavity of the UV reactor again for cyclic photocatalytic oxidation treatment. In this process, the wastewater is subjected to cyclic photocatalytic oxidation treatment in the oxidation circulation zone and the second cavity of the UV reactor, thereby achieving continuous degradation of organic matter. Another part of the wastewater enters the activated carbon filler zone at the upper part of the second reaction tank from bottom to top and is discharged from the second reaction tank outlet at the upper part of the second reaction tank. In this process, since the wastewater contains oxidants, oxidative free radicals, catalysts and bubbles generated by decomposition and oxidation, the bubbles have a scrubbing and backwashing effect on the activated carbon filler, and at the same time, the oxidants and oxidative free radicals oxidize the organic matter in the pores on the surface of the activated carbon to regenerate the activated carbon. The suspended matter backwashed is destabilized on the surface under the action of the oxidants and oxidative free radicals to form a charge layer, thereby improving the effect of subsequent flocculation and sedimentation removal. At the same time, due to the oxidation and backwashing of the filler zone, the residual oxidant in the wastewater is further consumed.

[0045] Further, the present invention is provided with at least one group of first reaction tanks and at least one group of second reaction tanks. The lower parts of the first reaction tank and the second reaction tank are both provided with a circulation inlet and a circulation outlet, the upper parts of the first reaction tank and the second reaction tank are both provided with a filtration inlet and a reaction tank outlet, and the bottoms of the first reaction tank and the second reaction tank are both provided with a filtration outlet; the first reaction tank and the second reaction tank can switch the filtration state and the oxidation backwash regeneration state through the valve system on the pipeline. Specifically, if used for filtration, the valves on the filtration inlet and filtration outlet pipelines are opened, and the valves on the circulation inlet, circulation outlet, and reaction tank outlet pipelines are closed; if used for oxidation backwash regeneration, the valves on the filtration inlet and filtration outlet pipelines are closed, and the valves on the circulation inlet, circulation outlet, and reaction tank outlet pipelines are opened. The present invention does not specifically limit the switching mode of each valve, and can adopt the conventional valve switching mode in the art, including but not limited to automatic control. Preferably, the switching cycle of the filtration state and the oxidation backwash regeneration state is 4-24h.

[0046] According to the treatment method of the present invention, in some embodiments, in step (6), the flocculation sedimentation treatment is: adjusting the pH value of the flocculation sedimentation tank to 7-9, adding a coagulant with a concentration of 5-15 mg / L, and the hydraulic retention time of the flocculation sedimentation tank is 1-3 hours. In some specific embodiments, the pH value of the flocculation sedimentation tank can be adjusted by adding alkali solution, and the alkali solution includes at least one of sodium hydroxide solution and potassium hydroxide solution. The present invention has no specific limitation on the type of the coagulant, and conventional coagulants in the art can be used, including but not limited to anionic polyacrylamide, cationic polyacrylamide, etc.

[0047] In the present invention, in step (6), in the flocculation sedimentation tank, under an alkaline environment, the added catalyst becomes a flocculant, and the suspended solids and part of the insoluble COD in the water are flocculated and settled. The coagulant can further improve the flocculation and settlement effect, and finally achieve mud and water separation. The mud residue can be discharged from the bottom of the flocculation sedimentation tank for conventional disposal, and the effluent is discharged from the outlet of the flocculation sedimentation tank.

[0048] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention by way of example, and are not intended to limit the present invention.

[0049] In the present invention, the testing methods of various performance parameters in the embodiments and comparative examples are as follows: Chemical oxygen demand COD: tested according to HJ828-2017 standard; Total organic carbon TOC: HJ501-2009; Total nitrogen content TN: tested according to BSEN12260-2003 standard; Ammonia nitrogen content: tested according to HJ / T195-2005 standard; Total phosphorus content: DIN EN ISO 6878-2004; Chlorobenzene content: HJ810-2016; Suspended matter content: GB / T11901-1989; Residual hydrogen peroxide: rapid test paper colorimetric method.

[0050] Reference Figure 1 , a wastewater advanced oxidation treatment process, the specific process is as follows: The wastewater enters the homogenization tank 1 for homogenization treatment, and the effluent enters the filter inlet 7 of the first reaction tank 2 through the lifting pump 6. At this time, the valves of the pipelines where the filter inlet 7 and the filter outlet 11 of the first reaction tank 2 are located are in the open state, and the valves of the pipelines where the circulation inlet 10, the circulation outlet 9, and the first reaction tank outlet 8 of the first reaction tank 2 are located are in the closed state. The wastewater flows from top to bottom through the activated carbon filler area 2-1 and the oxidation circulation area 2-2 of the first reaction tank 2, and then enters the first cavity of the UV reactor through the filter outlet 11 through the first inlet 4-7 of the UV reactor. The effluent of the first cavity flows out from the first outlet 4-8 and mixes with the oxidant and the catalyst, and enters the second cavity of the UV reactor through the second inlet 4-9 through the circulation pump 12 for UV light Catalytic oxidation treatment; the effluent from the second cavity flows out from the second outlet 4-10 and enters the oxidation circulation zone 3-2 at the lower part of the second reaction tank 3 through the circulation inlet 13 of the second reaction tank 3, a part of the wastewater is discharged through the circulation outlet 14 of the oxidation circulation zone 3-2, and enters the second cavity of the UV reactor again for cyclic photocatalytic oxidation treatment, and the other part of the wastewater passes through the oxidation circulation zone 3-2 and the activated carbon filler zone 3-1 of the second reaction tank 3 from bottom to top, and is discharged from the second reaction tank outlet 17 at the upper part of the second reaction tank 3; the effluent from the second reaction tank outlet 17 enters the flocculation sedimentation tank 5, alkali solution and coagulant are added for flocculation sedimentation treatment, the sludge is discharged from the bottom of the flocculation sedimentation tank 5 and then conventionally disposed, and the effluent is discharged through the flocculation sedimentation tank outlet.

[0051] Reference Figure 2A UV reactor 4 comprises a reactor cavity, which is formed by wrapping a shell 4-1. A first quartz sleeve 4-2 is arranged in the middle of the reactor cavity, and an ultraviolet lamp 4-4 is built in the first quartz sleeve 4-2. Both ends of the ultraviolet lamp 4-4 are connected to a power source through a connecting wire 4-11. A second quartz sleeve 4-3 is sleeved on the outer side of the first quartz sleeve 4-2. The area between the first quartz sleeve 4-2 and the second quartz sleeve 4-3 is a first cavity 4-5, and the area between the second quartz sleeve 4-3 and the shell 4-1 is a second cavity 4-6; a first inlet 4-7 is arranged at the lower part of the first cavity 4-5, and a first outlet 4-8 is arranged at the upper part of the first cavity 4-5; a second inlet 4-9 is arranged at the lower part of the second cavity 4-6, and a second outlet 4-10 is arranged at the upper part of the second cavity 4-6.

[0052] Example 1 A wastewater advanced oxidation treatment process, such as Figure 1 As shown. Specifically including the steps: (1) Homogenization treatment: The wastewater from a rubber plant (COD of 300-400 mg / L, total phosphorus content of 10-15 mg / L, chlorobenzene content of 80-100 mg / L, suspended solids content of 100-200 mg / L, milky white color) enters homogenization tank 1 for homogenization treatment. The hydraulic retention time in the homogenization tank is 2 h.

[0053] (2) Filtration and adsorption: The effluent enters the filtration inlet 7 of the first reaction tank 2 through the lifting pump 6. At this time, the valves of the pipelines where the filtration inlet 7 and the filtration outlet 11 of the first reaction tank 2 are located are in the open state, and the valves of the pipelines where the circulation inlet 10, the circulation outlet 9 and the first reaction tank outlet 8 of the first reaction tank 2 are in the closed state. The wastewater flows from top to bottom through the activated carbon filling area 2-1 and the oxidation circulation area 2-2 of the first reaction tank 2. The activated carbon filling area 2-1 is filled with granular activated carbon filler. The hydraulic retention time of the first reaction tank 2 is 3 hours, the hydraulic retention time of the activated carbon filling area 2-1 is 1 hour, and the hydraulic retention time of the oxidation circulation area 2-2 is 2 hours.

[0054] (3) UV light oxidation treatment: The filtered water flows out through the filter outlet 11 of the first reaction tank, enters the first cavity 4-5 of the UV reactor through the first inlet 4-7 of the UV reactor for UV light oxidation treatment, and the outlet water temperature of the first cavity 4-5 is controlled to be 50-52°C.

[0055] (4) UV photocatalytic oxidation treatment: The effluent from the first chamber 4-5 flows out from the first outlet 4-8 and is mixed with hydrochloric acid, hydrogen peroxide solution, and trivalent iron salt with a mass concentration of 30%. The mass ratio of the dry basis dosage of hydrogen peroxide solution to the influent COD is 10:1. The effluent enters the second chamber 4-6 of the UV reactor through the second inlet 4-9 via the circulation pump 12. The total iron concentration at the outlet of the circulation pump is controlled to be 100 mg / L, and the flow rate of the circulation pump is 5 times the flow rate of the booster pump.

[0056] (5) Circulation oxidation and regeneration: The effluent of the second chamber 4-6 flows out from the second outlet 4-10 and enters the oxidation circulation zone 3-2 at the lower part of the second reaction tank 3 through the circulation inlet 13 of the second reaction tank 3, and the pH value of the second reaction tank 3 is controlled to be 2.5-2.7. A part of the wastewater is discharged through the circulation outlet 14 of the oxidation circulation zone 3-2 and enters the second chamber 4-6 of the UV reactor again for cyclic photocatalytic oxidation treatment. The other part of the wastewater passes through the oxidation circulation zone 3-2 and the activated carbon filler zone 3-1 of the second reaction tank 3 from bottom to top, and is discharged from the second reaction tank outlet 17 at the upper part of the second reaction tank 3; wherein, the ratio of the wastewater flow rate discharged through the circulation outlet to the wastewater flow rate at the filter inlet of the first reaction tank is 4:1, and the flow rate of the other part of the wastewater is the same as the wastewater flow rate at the filter inlet of the first reaction tank.

[0057] (6) Flocculation and sedimentation: The effluent from the outlet 17 of the second reaction tank enters the flocculation sedimentation tank 5, and sodium hydroxide solution is added to adjust the pH value to 7-9. Cationic polyacrylamide with a concentration of 15 mg / L is added. The hydraulic retention time of the flocculation sedimentation tank 5 is 2 hours. The sludge is discharged from the bottom of the flocculation sedimentation tank 5 and then conventionally disposed. The effluent is discharged from the outlet of the flocculation sedimentation tank.

[0058] The UV lamp in the UV reactor has a wavelength of 180-400nm and an installed power of 2000W / m 3 The distance between the outer wall of the first quartz sleeve 4-2 and the inner wall of the second quartz sleeve 4-3 is 40mm, the distance between the inner wall of the shell 4-1 and the outer wall of the second quartz sleeve 4-3 is 140mm, and the shell is made of 316 stainless steel lined with anti-corrosion reflective coating; the hydraulic retention time of the first cavity and the second cavity is 80s in total.

[0059] After testing: the residual hydrogen peroxide content in the effluent from the flocculation sedimentation tank is <3mg / L, the chlorobenzene content is <0.2mg / L, the COD is 20-25mg / , the TOC is 10-13mg / L, the total phosphorus content is 0.1-0.2mg / L, and the suspended matter content is 8-15mg / L.

[0060] Example 2 A wastewater advanced oxidation treatment process, such as Figure 1 As shown. Specifically including the steps: (1) Homogenization treatment: The recycled reverse osmosis concentrated water (COD is 100-150 mg / L, TOC is 32-61 mg / L, and total phosphorus content is 2-6 mg / L) enters the homogenization tank 1 for homogenization treatment. The hydraulic retention time in the homogenization tank is 8 hours.

[0061] (2) Filtration and adsorption: The effluent enters the filtration inlet 7 of the first reaction tank 2 through the lifting pump 6. At this time, the valves of the pipelines where the filtration inlet 7 and the filtration outlet 11 of the first reaction tank 2 are located are in the open state, and the valves of the pipelines where the circulation inlet 10, the circulation outlet 9 and the first reaction tank outlet 8 of the first reaction tank 2 are in the closed state. The wastewater flows from top to bottom through the activated carbon filling area 2-1 and the oxidation circulation area 2-2 of the first reaction tank 2. The activated carbon filling area 2-1 is filled with granular activated carbon filler. The hydraulic retention time of the first reaction tank 2 is 1 hour, the hydraulic retention time of the activated carbon filling area 2-1 is 0.2 hours, and the hydraulic retention time of the oxidation circulation area 2-2 is 0.8 hours.

[0062] (3) UV light oxidation treatment: The filtered water flows out through the filter outlet 11 of the first reaction tank, enters the first cavity 4-5 of the UV reactor through the first inlet 4-7 of the UV reactor for UV light oxidation treatment, and the outlet water temperature of the first cavity 4-5 is controlled to be 45-47°C.

[0063] (4) UV photocatalytic oxidation treatment: The effluent from the first chamber 4-5 flows out from the first outlet 4-8 and is mixed with hydrochloric acid, hydrogen peroxide solution, and trivalent iron salt with a mass concentration of 30%. The mass ratio of the dry basis dosage of hydrogen peroxide solution to the influent COD is 3:1. The effluent enters the second chamber 4-6 of the UV reactor through the second inlet 4-9 via the circulation pump 12. The total iron concentration at the outlet of the circulation pump is controlled to be 100 mg / L, and the circulation pump flow rate is 9 times the lift pump flow rate.

[0064] (5) Circulation oxidation and regeneration: The effluent of the second chamber 4-6 flows out from the second outlet 4-10 and enters the oxidation circulation zone 3-2 at the lower part of the second reaction tank 3 through the circulation inlet 13 of the second reaction tank 3, and the pH value of the second reaction tank 3 is controlled to be 2.8-3.0. A part of the wastewater is discharged through the circulation outlet 14 of the oxidation circulation zone 3-2 and enters the second chamber 4-6 of the UV reactor again for cyclic photocatalytic oxidation treatment. The other part of the wastewater passes through the oxidation circulation zone 3-2 and the activated carbon filler zone 3-1 of the second reaction tank 3 from bottom to top, and is discharged from the second reaction tank outlet 17 at the upper part of the second reaction tank 3; wherein, the ratio of the wastewater flow rate discharged through the circulation outlet to the wastewater flow rate at the filter inlet of the first reaction tank is 8:1, and the flow rate of the other part of the wastewater is the same as the flow rate of the wastewater at the filter inlet of the first reaction tank.

[0065] (6) Flocculation and sedimentation: The effluent from the outlet 17 of the second reaction tank enters the flocculation sedimentation tank 5, and sodium hydroxide solution is added to adjust the pH value to 7-9. Anionic polyacrylamide with a concentration of 5 mg / L is added. The hydraulic retention time of the flocculation sedimentation tank 5 is 1 hour. The sludge is discharged from the bottom of the flocculation sedimentation tank 5 and then conventionally disposed. The effluent is discharged from the outlet of the flocculation sedimentation tank.

[0066] The UV lamp in the UV reactor has a wavelength of 180-400nm and an installed power of 200W / m 3 The distance between the outer wall of the first quartz sleeve 4-2 and the inner wall of the second quartz sleeve 4-3 is 100 mm, the distance between the inner wall of the shell 4-1 and the outer wall of the second quartz sleeve 4-3 is 100 mm, and the shell is made of quartz glass; the hydraulic retention time of the first cavity and the second cavity is 120 s in total.

[0067] After testing: no residual hydrogen peroxide was detected in the effluent from the flocculation sedimentation tank, COD was 25-29 mg / L, TOC was 12-15 mg / L, and total phosphorus content was 0.01-0.05 mg / L.

[0068] Example 3 A wastewater advanced oxidation treatment process, such as Figure 1 As shown. Specifically including the steps: (1) Homogenization treatment: Wastewater from a rubber plant (COD is 500-650 mg / L, TOC is 500-650 mg / L, and suspended matter content is 100-300 mg / L) enters homogenization tank 1 for homogenization treatment. The hydraulic retention time in the homogenization tank is 1 hour.

[0069] (2) Filtration and adsorption: The effluent enters the filtration inlet 7 of the first reaction tank 2 through the lifting pump 6. At this time, the valves of the pipelines where the filtration inlet 7 and the filtration outlet 11 of the first reaction tank 2 are located are in the open state, and the valves of the pipelines where the circulation inlet 10, the circulation outlet 9 and the first reaction tank outlet 8 of the first reaction tank 2 are in the closed state. The wastewater flows from top to bottom through the activated carbon filling area 2-1 and the oxidation circulation area 2-2 of the first reaction tank 2. The activated carbon filling area 2-1 is filled with granular activated carbon filler. The hydraulic retention time of the first reaction tank 2 is 6 hours, the hydraulic retention time of the activated carbon filling area 2-1 is 2 hours, and the hydraulic retention time of the oxidation circulation area 2-2 is 4 hours.

[0070] (3) UV light oxidation treatment: The filtered water flows out through the filter outlet 11 of the first reaction tank, enters the first cavity 4-5 of the UV reactor through the first inlet 4-7 of the UV reactor for UV light oxidation treatment, and the outlet water temperature of the first cavity 4-5 is controlled to be 48-50°C.

[0071] (4) UV photocatalytic oxidation treatment: The effluent from the first chamber 4-5 flows out from the first outlet 4-8 and is mixed with hydrochloric acid, hydrogen peroxide solution, and divalent iron salt with a mass concentration of 30%. The mass ratio of the dry basis dosage of hydrogen peroxide solution to the influent COD is 6:1. The effluent enters the second chamber 4-6 of the UV reactor through the second inlet 4-9 through the circulation pump 12. The total iron concentration at the outlet of the circulation pump is controlled to be 80 mg / L, and the circulation pump flow rate is twice the flow rate of the booster pump.

[0072] (5) Circulation oxidation and regeneration: The effluent of the second chamber 4-6 flows out from the second outlet 4-10 and enters the oxidation circulation zone 3-2 at the lower part of the second reaction tank 3 through the circulation inlet 13 of the second reaction tank 3, and the pH value of the second reaction tank 3 is controlled to be 2.7-2.9. A part of the wastewater is discharged through the circulation outlet 14 of the oxidation circulation zone 3-2 and enters the second chamber 4-6 of the UV reactor again for cyclic photocatalytic oxidation treatment. The other part of the wastewater passes through the oxidation circulation zone 3-2 and the activated carbon filler zone 3-1 of the second reaction tank 3 from bottom to top, and is discharged from the second reaction tank outlet 17 at the upper part of the second reaction tank 3; wherein, the ratio of the wastewater flow rate discharged through the circulation outlet to the wastewater flow rate at the filter inlet of the first reaction tank is 1:1, and the flow rate of the other part of the wastewater is the same as the wastewater flow rate at the filter inlet of the first reaction tank.

[0073] (6) Flocculation and sedimentation: The effluent from the outlet 17 of the second reaction tank enters the flocculation sedimentation tank 5, and sodium hydroxide solution is added to adjust the pH value to 7-9. Cationic polyacrylamide with a concentration of 10 mg / L is added. The hydraulic retention time of the flocculation sedimentation tank 5 is 3 hours. The sludge is discharged from the bottom of the flocculation sedimentation tank 5 and then conventionally disposed. The effluent is discharged from the outlet of the flocculation sedimentation tank.

[0074] The UV lamp in the UV reactor has a wavelength of 180-400nm and an installed power of 1000W / m 3 The distance between the outer wall of the first quartz sleeve 4-2 and the inner wall of the second quartz sleeve 4-3 is 140mm, the distance between the inner wall of the shell 4-1 and the outer wall of the second quartz sleeve 4-3 is 40mm, and the shell is made of 316 stainless steel lined with anti-corrosion coating; the hydraulic retention time of the first cavity and the second cavity is 60s in total.

[0075] After testing: the residual hydrogen peroxide in the effluent from the flocculation sedimentation tank is less than 2mg / L, COD is 20-30mg / L, TOC is 12-15mg / L, and the suspended matter content is 5-15mg / L.

[0076] Comparative Example 1 The wastewater quality and wastewater advanced oxidation treatment process of this comparative example are the same as those of Example 1, except that the UV reactor of this comparative example only contains the first quartz sleeve, and the second quartz sleeve is not provided.

[0077] After testing: the residual hydrogen peroxide in the effluent from the flocculation sedimentation tank is less than 3 mg / L, the chlorobenzene content is less than 0.2 mg / L, the COD is 60-80 mg / L, the TOC is 23-30 mg / L, the total phosphorus content is 0.2-0.3 mg / L, and the suspended matter content is 8-15 mg / L.

[0078] Comparative Example 2 The wastewater quality and wastewater advanced oxidation treatment process of this comparative example are the same as those of Example 1, except that this comparative example does not have a first reaction tank and there is no activated carbon filling area in the second reaction tank.

[0079] After testing: the residual hydrogen peroxide in the effluent of the flocculation sedimentation tank is 100-300 mg / L, the chlorobenzene content is 0.2-0.5 mg / L, the COD is 100-180 mg / L, the TOC is 30-38 mg / L, the total phosphorus content is 0.3-0.5 mg / L, and the suspended matter content is 22-35 mg / L.

[0080] It can be seen from Example 1 and Comparative Example 1 that under the condition that other process conditions are the same, the UV reactor in Comparative Example 1 contains only the first quartz sleeve, and the second quartz sleeve is not set. The test results of the final effluent are worse than those in Example 1, especially the COD and TOC contents in the effluent are significantly higher than those in Example 1. The reason is that the bubbles or catalysts generated by the catalysis in the UV reactor hinder the ultraviolet light from photolyzing organic matter, and the light energy fails to be fully utilized. It can be seen from Example 1 and Comparative Example 2 that under the condition that other process conditions are the same, Comparative Example 2 does not set the first reaction tank, and there is no activated carbon filling area in the second reaction tank. The indicators in the final effluent are significantly worse than those in Example 1. The reason is that the activated carbon in Example 1 has an intercepting effect on the milky turbidity in the wastewater, which improves the oxidation efficiency, and the backwashing activated carbon process consumes the residual hydrogen peroxide oxidation agent. It can be seen that the present application, by designing a special advanced oxidation treatment process and device, efficiently utilizes the role of different bands of medium-pressure ultraviolet in water treatment, improves the utilization rate of ultraviolet light, and has the characteristics of high oxidation efficiency, strong oxidation ability, and full utilization of ultraviolet light energy.

[0081] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A wastewater advanced oxidation treatment process, characterized in that: The steps include: (1) Homogenization treatment: wastewater enters the homogenization tank for homogenization treatment; (2) Filtration and adsorption: The water from the homogenization tank enters the first reaction tank for filtration. The first reaction tank is provided with an activated carbon filling area and an oxidation circulation area from top to bottom; (3) UV light oxidation treatment: The filtered water enters the first chamber of the UV reactor for UV light oxidation treatment; (4) UV photocatalytic oxidation treatment: The water from the first chamber is mixed with the catalyst and oxidant and enters the second chamber of the UV reactor for UV photocatalytic oxidation treatment in an acidic environment; (5) Circular oxidation and regeneration: The effluent from the second chamber enters the oxidation circulation zone at the lower part of the second reaction tank. A portion of the wastewater is discharged through the circulation outlet of the oxidation circulation zone and enters the second chamber of the UV reactor again for cyclic photocatalytic oxidation treatment. The other portion of the wastewater enters the activated carbon filler zone at the upper part of the second reaction tank from bottom to top and is discharged from the second reaction tank outlet at the upper part of the second reaction tank. (6) Flocculation and sedimentation: The effluent from the outlet of the second reaction tank enters the flocculation sedimentation tank for flocculation and sedimentation treatment. After treatment, the effluent can be discharged.

2. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: In step (1), the hydraulic retention time in the homogenization tank is 1-8 hours.

3. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: In step (2), the hydraulic retention time in the first reaction tank is 1-6 hours, wherein the hydraulic retention time in the activated carbon filler zone is 0.2-2 hours, and the hydraulic retention time in the oxidation circulation zone is 0.8-4 hours.

4. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: The UV reactor comprises a reactor cavity, which is formed by being wrapped by a shell; a first quartz sleeve is arranged in the middle of the reactor cavity, an ultraviolet lamp is built in the first quartz sleeve, both ends of the ultraviolet lamp are connected to a power supply, a second quartz sleeve is arranged outside the first quartz sleeve, the area between the first quartz sleeve and the second quartz sleeve is the first cavity, and the area between the second quartz sleeve and the shell is the second cavity; a first inlet is arranged at the lower part of the first cavity, and a first outlet is arranged at the upper part of the first cavity; a second inlet is arranged at the lower part of the second cavity, and a second outlet is arranged at the upper part of the second cavity; wherein the distance between the inner wall of the second quartz sleeve and the outer wall of the first quartz sleeve is 40-140 mm, and the distance between the inner wall of the shell and the outer wall of the second quartz sleeve is 40-140 mm.

5. The wastewater advanced oxidation treatment process according to claim 4, characterized in that: The wavelength of the ultraviolet lamp is 180-400nm, and the installed power of the ultraviolet lamp is 200-2000W / m.

6. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: The first reaction tank and the second reaction tank are both provided with a circulation inlet and a circulation outlet at the lower part, the first reaction tank and the second reaction tank are both provided with a filtration inlet and a reaction tank outlet at the upper part, and the first reaction tank and the second reaction tank are both provided with a filtration outlet at the bottom; the first reaction tank and the second reaction tank can be switched by a valve system on the pipeline.

7. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: The hydraulic retention time of the first cavity and the second cavity is 60-120s in total, and the outlet water temperature of the first cavity is 45-52°C.

8. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: In step (4), the pH value of the UV photocatalytic oxidation treatment is 2.5-3.0; the catalyst includes at least one of a trivalent iron salt and a divalent iron salt aqueous solution; and the oxidant includes at least one of a hydrogen peroxide solution and ozone.

9. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: In step (5), the hydraulic retention time in the second reaction tank is 1-6 hours, wherein the hydraulic retention time in the activated carbon filler zone is 0.2-2 hours, and the hydraulic retention time in the oxidation circulation zone is 0.8-4 hours; the pH value in the second reaction tank is 2.5-3.

0.

10. The wastewater advanced oxidation treatment process according to claim 1, characterized in that: In step (6), the flocculation sedimentation treatment is as follows: the pH value of the flocculation sedimentation tank is adjusted to 7-9, a coagulant with a concentration of 5-15 mg / L is added, and the hydraulic retention time of the flocculation sedimentation tank is 1-3 h.

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