Ozone catalytic oxidation wastewater treatment device and method

Abstract

The invention relates to the field of environmental protection, and discloses a catalytic ozonation wastewater treatment device and method.The treatment device comprises a pretreatment unit and a catalytic reactor, the catalytic reactor is filled with a catalyst, the catalyst is cylindrical, through holes are formed in the catalyst, the specific surface area of the catalyst is 250-350 m < 2 > / g, the pore volume is 0.5-1.5 cm < 3 > / g, and the specific surface area of the catalyst is 200-300 m < 2 > / g. The catalyst comprises a catalytic carrier, an active component and an adsorption component, the catalytic carrier is a molecular sieve, the active component comprises one or more of oxides of Fe, Ru, Mn, Cu, Ni, Zn, Co, Ce and La, and the adsorption component comprises activated carbon. The refractory pollutants are gathered and effectively adsorbed into pores of the catalyst, so that the contact time of the adsorbed pollutants and ozone is greatly prolonged, the mass transfer efficiency between the adsorbed pollutants and the ozone is effectively improved, and the refractory pollutants adsorbed in the catalyst and wastewater are mineralized and decomposed.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, and in particular to an ozone catalytic oxidation wastewater treatment device and method. Background Art

[0002] Ozone has strong oxidizing ability and is widely used in wastewater treatment. Ozone oxidation to remove pollutants is mainly achieved through two pathways: oxidation and catalysis. Oxidation refers to the direct reaction of ozone with organic matter. This method has strong selectivity and usually has a good treatment effect on easily degradable pollutants such as unsaturated aliphatic hydrocarbons; catalysis refers to the decomposition of ozone to produce hydroxyl radicals (·OH), which react with pollutants through hydroxyl radicals (·OH). This method is not selective. Usually, in order to enhance the ability of ozone oxidation to generate hydroxyl radicals (·OH), ozone catalysts are generally added during the ozone oxidation process. Ozone catalysts can catalyze ozone to generate hydroxyl radicals (·OH), greatly enhancing the oxidation capacity of the system, thereby enhancing the removal efficiency of difficult-to-degrade pollutants and improving the wastewater treatment effect. However, when the existing ozone catalysts play a catalytic role, the contact between the pollutants in the wastewater and the catalyst is only transient, and the residence time is not sufficient. In addition, the specific surface area of ​​the existing catalysts is small, and the solid-liquid-gas three-phase catalytic mass transfer effect is not high during the catalytic reaction, resulting in unsatisfactory catalytic effect. Summary of the invention

[0003] The purpose of the present invention is to overcome the problems existing in the prior art, such as insufficient contact time between pollutants and catalysts, small specific surface area of ​​catalysts, and unsatisfactory catalytic effect. An ozone catalytic oxidation wastewater treatment device and method are provided. The ozone catalyst loaded in the device can prolong the contact time between pollutants and catalysts, and the specific surface area of ​​the catalyst is large, so the treatment effect on wastewater is better.

[0004] In order to achieve the above-mentioned object, the first aspect of the present invention provides an ozone catalytic oxidation wastewater treatment device, wherein the treatment device comprises: a pre-treatment unit and a catalytic reactor, wherein the drain outlet of the pre-treatment unit is connected to the catalytic water inlet of the catalytic reactor, the catalytic reactor is provided with a catalytic air inlet at the bottom, and has a catalytic bed layer therein, the catalytic bed layer is filled with a catalyst, and the catalytic reactor is also provided with a catalytic water outlet;

[0005] The catalyst comprises a catalyst carrier, an active component and an adsorption component, the catalyst carrier is a molecular sieve, the active component comprises one or more of oxides of Fe, Ru, Mn, Cu, Ni, Zn, Co, Ce and La, and the adsorption component comprises activated carbon;

[0006] The catalyst is cylindrical and has through holes inside. The specific surface area of ​​the catalyst is 250-350m 2 / g, pore volume is 0.5-1.5cm 3 / g.

[0007] The second aspect of the present invention provides a method for treating wastewater by ozone catalytic oxidation, wherein the treatment method comprises: contacting the wastewater to be treated with ozone in the catalytic reactor in the treatment device according to the first aspect of the present invention for reaction.

[0008] Through the above technical scheme, after the wastewater enters the catalytic reactor, it contacts with the catalyst, an adsorption reaction occurs, and the difficult-to-degrade pollutants are gathered and effectively adsorbed in the pores of the catalyst, and under the catalytic action of the catalyst, ozone undergoes a catalytic reaction to generate a strongly oxidizing hydroxyl radical (·OH), thereby greatly extending the contact time between the adsorbed pollutants and the ozone and hydroxyl radical (·OH), effectively improving the mass transfer efficiency between them, and the difficult-to-degrade pollutants adsorbed in the catalyst and in the wastewater are mineralized and decomposed. At the same time, in this process, since the catalyst has a large specific surface area, the solid-liquid-gas three-phase catalytic mass transfer effect is effectively improved, and the two work synergistically to improve the efficiency of pollutant removal. The present invention has a rigorous concept, a reasonable design, and a good application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of the structure of the processing device;

[0010] Figure 2 is an appearance diagram of the catalyst prepared in Preparation Example 1;

[0011] Figure 3 This is a scanning electron microscope (SEM) image of the catalyst prepared in Preparation Example 1.

[0012] Description of Reference Numerals

[0013] 1-water inlet pool; 2-water inlet pump; 3-oxidation water inlet; 4-oxidation air inlet; 5-oxidation aeration plate; 6-oxidation water distributor; 7-oxidation reactor; 8-oxidation drain outlet; 9-oxidation exhaust outlet; 10-first check valve; 11-second check valve; 12-ozone generator; 13-third check valve; 14-catalytic air inlet; 15-catalytic water inlet; 16-catalytic aeration plate; 17-catalytic water distributor; 18-catalytic bed; 19-catalytic reactor; 20-catalytic drain outlet; 21-catalytic exhaust outlet; 22-water outlet pool; 23-gas-liquid separator; 24-tail gas destroyer. DETAILED DESCRIPTION

[0014] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0015] In the description of the present application, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0016] The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0017] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0018] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0019] The first aspect of the present invention provides an ozone catalytic oxidation wastewater treatment device, wherein the treatment device comprises: a pre-treatment unit and a catalytic reactor, wherein the drain outlet of the pre-treatment unit is connected to the catalytic water inlet of the catalytic reactor, the catalytic reactor is provided with a catalytic air inlet at the bottom, and has a catalytic bed layer therein, the catalytic bed layer is filled with a catalyst, and the catalytic reactor is also provided with a catalytic water outlet;

[0020] The catalyst comprises a catalyst carrier, an active component and an adsorption component, the catalyst carrier is a molecular sieve, the active component comprises one or more of oxides of Fe, Ru, Mn, Cu, Ni, Zn, Co, Ce and La, and the adsorption component comprises activated carbon;

[0021] The catalyst is cylindrical and has through holes inside. The specific surface area of ​​the catalyst is 250-350m 2 / g, pore volume is 0.5-1.5cm 3 / g.

[0022] The specific surface area is related to the solid-liquid-gas mass transfer effect of the catalyst and directly affects the catalytic effect. The pore volume affects the adsorption effect of the catalyst on pollutants. The catalyst in the device provided by the present invention has a large specific surface area and pore volume, and also has a specific through-hole structure. The combined effect of these makes the catalyst have good adsorption and catalytic capabilities. The specific surface area of ​​the catalyst can be 250m 2 / g, 280m 2 / g、300m 2 / g, 330m 2 / g, 350m 2 / g, the pore volume can be any value within the range of any two values, 0.5cm 3 / g, 0.8cm 3 / g, 1.0cm 3 / g, 1.2cm 3 / g, 1.5cm 3 Any value within the range of any two values ​​in / g.

[0023] In some embodiments, preferably, based on the total amount of the catalyst, the amount of the catalytic carrier is 60-70wt%, the amount of the active component is 10-20wt%, and the amount of the adsorbed component is 15-30wt%. The amount of the carrier, the active component, and the adsorbed component is directly related to the catalytic adsorption effect. Based on the total amount of the catalyst, the amount of the catalytic carrier can be any value within any two numerical ranges of 60wt%, 62wt%, 65wt%, 68wt%, and 70wt%, the amount of the active component can be any value within any two numerical ranges of 10wt%, 13wt%, 15wt%, 17wt%, and 20wt%, and the amount of the adsorbed component can be any value within any two numerical ranges of 15wt%, 18wt%, 20wt%, 23wt%, 25wt%, 27wt%, and 30wt%.

[0024] In some embodiments, preferably, the activated carbon includes at least two or more of coal-based activated carbon, coconut shell activated carbon and fruit shell activated carbon. Selecting at least two activated carbon components can better improve the adsorption effect.

[0025] In some embodiments, preferably, based on the total amount of the catalyst, the amount of each activated carbon is 5-10 wt %. The amount of each activated carbon can be any value within any two numerical ranges of 5 wt %, 8 wt %, and 10 wt %.

[0026] In some embodiments, preferably, the filling rate of the catalyst is 10-50%. The filling rate refers to the percentage of the volume of the catalyst to the volume of the space in the catalytic reactor. In the structure provided by the present invention, the catalytic bed is only filled with catalyst. Compared with the existing technology that requires additional fillers to enhance the catalytic effect, the filler cost and filling time are saved, and the economic value is higher. The filling rate can be any value within any two numerical ranges of 10%, 20%, 30%, 40%, and 50%.

[0027] In some embodiments, preferably, the centerline of the through hole in the catalyst is parallel to the centerline of the catalyst, and the aperture of the through hole is 2-5 mm. In the present invention, a through hole is specially arranged in the catalyst, and the through hole can play a synergistic role with the void (pore volume) in the catalyst to significantly increase the mass transfer effect and improve the reaction effect. The aperture of the through hole can be any value within any two numerical ranges of 2 mm, 3 mm, 4 mm, and 5 mm.

[0028] In some embodiments, preferably, the number of the through holes is 3-7.

[0029] In some embodiments, preferably, the diameter and height of the catalyst are independently 15-25 mm, and the strength of the catalyst is 250-300 N / particle. The catalyst that meets the corresponding diameter and height requirements is one, and the strength of the catalyst directly affects its service life. The strength of a single catalyst is as high as 250 N or more, and the service life is not less than five years. Of course, the strength can also be any value within any two numerical ranges of 260 N / particle, 280 N / particle, and 300 N / particle.

[0030] In some embodiments, preferably, the active components include Fe2O3, CuO, RuO and ZnO. Based on the total amount of the catalyst, the amount of Fe2O3 is 3-7wt%, the amount of CuO is 1-5wt%, the amount of RuO is 3-7wt%, and the amount of ZnO is 5-9wt%. Selecting Fe2O3, CuO, RuO and ZnO as active components and matching them with a suitable amount ratio can more effectively improve the catalytic effect. The amount of Fe2O3 can be any value within any two numerical ranges of 3wt%, 5wt%, and 7wt%, the amount of CuO can be any value within any two numerical ranges of 1wt%, 3wt%, and 5wt%, the amount of RuO can be any value within any two numerical ranges of 3wt%, 5wt%, and 7wt%, and the amount of ZnO can be any value within any two numerical ranges of 5wt%, 7wt%, and 9wt%.

[0031] In some embodiments, preferably, the preparation method of the catalyst includes: grinding the catalytic carrier, the adsorption component and the active component, mixing and molding to obtain a cylindrical precursor, curing and drying the precursor, and then calcining under inert gas protection to obtain the catalyst.

[0032] In some embodiments, preferably, the particle sizes of the catalytic carrier, adsorption component and active component after grinding are independently 300-500 meshes. The particle size after grinding can be any value within any two numerical ranges of 300 meshes, 400 meshes and 500 meshes, preferably 350-450 meshes.

[0033] In some embodiments, preferably, the mixing time is 2-4 hours. The mixing time can be any value within any two numerical ranges of 2 hours, 3 hours, and 4 hours, preferably 2.5-3.5 hours.

[0034] In some embodiments, preferably, the health-preserving time is 24-48 hours. The health-preserving time can be any value within any two numerical ranges of 24 hours, 30 hours, 35 hours, 40 hours, 44 hours, and 48 hours, preferably 35-40 hours.

[0035] In some embodiments, preferably, the drying temperature is 100-110° C. and the drying time is 4-8 hours. The drying time can be any value within any two numerical ranges of 4 hours, 6 hours, and 8 hours, preferably 6-8 hours.

[0036] In some embodiments, preferably, the calcination temperature is 400-600°C, the time is 2-4h, and the heating rate is 1-2°C. The calcination temperature can be any value within any two numerical ranges of 400°C, 450°C, 500°C, 55°C, and 600°C, preferably 400-500°C; the calcination time can be any value within any two numerical ranges of 2h, 3h, and 4h, preferably 2-3h.

[0037] In some embodiments, preferably, the pre-treatment unit comprises: an oxidation reactor, the lower part of which has an oxidation water inlet and an oxidation air inlet, the oxidation air inlet and the catalytic air inlet are connected to the ozone generator at the same time, and the oxidation drain outlet at the upper part of the oxidation reactor is connected to the catalytic water inlet of the catalytic reactor. With this structure, the wastewater to be treated can first enter the oxidation reactor, contact with ozone in the oxidation reactor, and undergo an oxidation reaction, wherein easily decomposable pollutants are decomposed, and the oxidation reaction in the oxidation reactor and the adsorption-catalytic reaction in the catalytic reactor form a synergistic effect, which can effectively remove pollutants in the wastewater.

[0038] In some embodiments, preferably, the height of the oxidation drain port is greater than the height of the catalytic drain port of the catalytic reactor. With this structure, the wastewater in the oxidation reactor can flow into the catalytic reactor by gravity.

[0039] In some embodiments, preferably, the oxidation exhaust port at the top of the oxidation reactor and the catalytic exhaust port at the top of the catalytic reactor are both connected to a gas-liquid separator, and the gas outlet of the gas-liquid separator is connected to a tail gas destroyer. With this structure, the exhausted gas still contains a small amount of ozone, but the ozone concentration is very low and cannot be returned to the oxidation reactor or the catalytic reactor for continued use, so it can be discharged after treatment.

[0040] The second aspect of the present invention provides a method for treating wastewater by ozone catalytic oxidation, wherein the treatment method comprises: contacting the wastewater to be treated with ozone in the catalytic reactor in the treatment device described in the first aspect of the present invention for reaction.

[0041] In some embodiments, preferably, in the catalytic reactor, for each liter of the wastewater to be treated, the amount of ozone used is 50-200 mg, and the residence time is 60-120 min. For each liter of the wastewater to be treated, the amount of ozone used can be any value within any two numerical ranges of 50 mg, 80 mg, 100 mg, 130 mg, 150 mg, and 200 mg, and the residence time can be any value within any two numerical ranges of 60 min, 80 min, 100 min, and 120 min.

[0042] In some embodiments, preferably, the treatment method further comprises: pre-treating the wastewater to be treated, wherein the pre-treatment comprises pre-oxidizing the wastewater to be treated with ozone in the pre-treatment unit, and then contacting the pre-oxidized wastewater to be treated with ozone in the catalytic reactor for reaction.

[0043] In some embodiments, preferably, in the pre-treatment unit, for each liter of the wastewater to be treated, the amount of ozone used is 50-100 mg, and the residence time is 30-60 min. For each liter of the wastewater to be treated, the amount of ozone used can be any value within any two numerical ranges of 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, and 100 mg, and the residence time can be any value within any two numerical ranges of 30 min, 40 min, 50 min, and 60 min.

[0044] In some embodiments, preferably, the total organic carbon of the wastewater to be treated is 70-100 mg / L, the chemical oxygen demand is 200-300 mg / L, and the chromaticity is 260-300. The method provided by this method is very suitable for treating wastewater with greater treatment difficulty. The total organic carbon (TOC) of the wastewater to be treated can be any value within any two numerical ranges of 70 mg / L, 80 mg / L, 90 mg / L, and 100 mg / L, the chemical oxygen demand (COD) can be any value within any two numerical ranges of 200 mg / L, 220 mg / L, 240 mg / L, 260 mg / L, 280 mg / L, and 300 mg / L, and the chromaticity can be any value within any two numerical ranges of 260, 270, 280, 290, and 300.

[0045] The specific surface area of ​​the catalyst provided by the present invention is 300-350m 2 / g, pore volume is 1-1.5cm 3 / g, based on the total amount of the catalyst, the amount of the catalytic carrier is 60-70wt%, the amount of the active component is 10-20wt%, and the amount of the adsorbent component is 15-30wt%, wherein the activated carbon includes coal-based activated carbon, coconut shell activated carbon and fruit shell activated carbon, and the active components include Fe2O3, CuO, RuO and ZnO, based on the total amount of the catalyst, the amount of Fe2O3 is 3-5wt%, the amount of CuO is 1-3wt%, the amount of RuO is 3-5wt%, and the amount of ZnO is 5-7wt%. It also has a good treatment effect on total organic carbon of 450-550mg / L, chemical oxygen demand of 150-250mg / L, and chromaticity of 280-320.

[0046] The present invention will be described in detail below by way of examples. In the following examples, the specific surface area and pore volume are measured by nitrogen adsorption method (specific reference is made to the determination of specific surface area and pore volume in HG / T3927-2020); the strength is measured by KQ-3 particle strength tester; the test methods for TOC, COD and chromaticity are combustion oxidation-non-dispersive infrared absorption method, "Determination of Chemical Oxygen Demand of Water Quality by Dichromate Method" (HJ 828-2017) and ISO 7887-1985 "Inspection and Determination of Water Color". The raw materials used in the following preparation examples, examples and comparative examples are commercially available unless otherwise specified.

[0047] The following examples and some comparative examples are based on the following ozone catalytic oxidation wastewater treatment device, the specific structure of which is as follows:

[0048] like Figure 1 As shown, the treatment device includes: a pre-treatment unit and a catalytic reactor 19, wherein the drain outlet of the pre-treatment unit is connected to the catalytic water inlet 15 of the catalytic reactor 19, the catalytic reactor 19 is provided with a catalytic air inlet 14 at the lower part, and has a catalytic bed 18 therein, the catalytic bed 18 is filled with a catalyst, the filling rate of the catalytic bed 18 is 10-50%, and the catalytic reactor 19 is also provided with a catalytic water outlet 20.

[0049] The treatment device may further include a water inlet system, which includes an inlet pool 1 and an inlet pump 2 connected in sequence.

[0050] The pre-treatment unit includes: an oxidation reactor 7, the lower part of which is provided with an oxidation water inlet 3 and an oxidation air inlet 4, wherein the oxidation water inlet 3 is connected to the water inlet pump 2, and the oxidation air inlet 4 and the catalytic air inlet 14 are simultaneously connected to the ozone generator 12, wherein the ozone generator 12 is connected to a main air supply pipe, on which a second check valve 11 is arranged, and the main air supply pipe is connected to the oxidation air inlet 4 and the catalytic air inlet 14 respectively through a first branch pipe and a second branch pipe, wherein the first branch pipe is provided with a first check valve 10, and the second branch pipe is provided with a third check valve 13.

[0051] In order to increase the contact between gas and wastewater, an oxidation aeration plate 5 and an oxidation water distributor 6 are provided at the lower part of the oxidation reactor 7, wherein the oxidation water distributor 6 is connected to the oxidation water inlet 3, and the oxidation aeration plate 5 is connected to the oxidation air inlet 4; a catalytic aeration plate 16 and a catalytic water distributor 17 are provided at the lower part of the catalytic reactor 19, and the catalytic aeration plate 16 and the catalytic water distributor 17 are both located below the catalytic bed 18, wherein the catalytic water distributor 17 is connected to the catalytic water inlet 15, and the catalytic aeration plate 16 is connected to the catalytic air inlet 14; an oxidation drain outlet 8 at the upper part of the oxidation reactor 7 is connected to the lower catalytic water inlet 15 of the catalytic reactor 19, and the height of the oxidation drain outlet 8 is greater than the height of the catalytic water outlet 20 of the catalytic reactor 19.

[0052] The highest points of the first branch pipe and the second branch pipe are higher than the heights of the oxidation drain outlet 8 and the catalytic water outlet 20, so as to prevent wastewater from flowing back into the ozone generator 12 when the work is stopped.

[0053] The oxidation exhaust port 9 at the top of the oxidation reactor 7 and the catalytic exhaust port 21 at the top of the catalytic reactor 19 are connected to a gas-liquid separator 23 at the same time. The gas outlet of the gas-liquid separator 23 is connected to an exhaust gas destroyer 24. The catalytic water outlet 20 of the catalytic reactor 19 is connected to a water outlet pool 22.

[0054] The oxidation reactor 7 can be a metal tower structure or a cement pool structure, with no filler inside, so that the oxidation capacity of ozone can be fully utilized. Ozone is generated by the ozone generator 12 and enters the oxidation reactor 7 through the second check valve 11 and the first check valve 10 from the oxidation air inlet 4. Under the action of the oxidation aeration disk 5, it is evenly divided into ozone microbubbles. The ozone bubbles and wastewater are fully mixed in the oxidation reactor 7, and an oxidation reaction occurs.

[0055] The catalytic reactor 19 can be a metal tower structure or a cement pool structure, which has a catalytic bed 18 therein. The catalyst is used to catalyze ozone to generate hydroxyl radicals (·OH). The effluent of the oxidation reaction 7 is discharged from the oxidation drain port 8 and enters the catalytic reactor 19 from the catalytic water inlet 15. Under the action of the catalytic water distributor 17, the wastewater is evenly distributed. Ozone is generated by the ozone generator and enters the catalytic reactor 19 from the catalytic air inlet 14 through the second check valve 11 and the third check valve 13. Under the action of the catalytic aeration plate 16, it is evenly divided into ozone microbubbles. The ozone microbubbles are fully mixed with the wastewater in the catalytic reactor 19 and contact the catalytic bed 18 upward. The pollutants in the wastewater are first adsorbed by the catalyst and gathered in the catalyst gaps. Then, under the catalytic action, a catalytic reaction occurs, and the ozone is decomposed to generate hydroxyl radicals, which mineralize and decompose the pollutants gathered in the catalyst pores and other pollutants in the water, thereby achieving the purpose of removing pollutants.

[0056] The effluent from the catalytic reactor 19 leaves from the catalytic water outlet 20 and enters the effluent pool 22. The ozone after the catalytic reaction is discharged from the catalytic exhaust port 21, and the ozone after the oxidation reaction is discharged from the oxidation exhaust port 9. The ozone after the catalytic reaction and the ozone after the oxidation reaction enter the gas-liquid separator 23 together, and enter the exhaust gas destroyer 24 after separation, and are discharged after decomposition and meeting the emission standards.

[0057] Preparation Example 1

[0058] ① Grinding: Based on the total amount of the catalyst, 60wt% of molecular sieve (purchased from Pingxiang Global New Materials Co., Ltd., model 13X), 5wt% of coal-based activated carbon, 5wt% of coconut shell activated carbon, 10wt% of fruit shell activated carbon, 5wt% of Fe2O3, 3wt% of CuO, 5wt% of RuO, and 7wt% of ZnO were ground to a particle size of 400 meshes to obtain a first mixed material;

[0059] ② Mixing: Add 20 wt% of water (based on the amount of the first mixture) to the first mixture, mix, and stir for 3 hours to obtain a uniform paste;

[0060] ③ Molding: Put the paste into a molding machine and extrude it to obtain a cylindrical, porous precursor. The diameter and height of the precursor are both 20 mm, the through hole is parallel to the center line of the column, the pore diameter is 3 mm, and the number of holes is 6;

[0061] ④ Curing: curing the catalyst precursor at room temperature (about 20° C.) for 36 hours;

[0062] ⑤ Drying: Place the cured catalyst precursor in a drying oven at a drying temperature of 105°C for 6 hours;

[0063] ⑥ Calcination: Place the dried catalyst precursor into a tubular furnace (under the protection of an inert gas such as nitrogen), heat to 500°C at a temperature gradient of 1.5°C / min, and calcine for 3 hours.

[0064] Preparation Example 2

[0065] The preparation was carried out in the manner of Preparation Example 1, except that: 60wt% molecular sieve, 10wt% coal-based activated carbon, 10wt% coconut shell activated carbon, 10wt% fruit shell activated carbon, 3wt% Fe2O3, 1wt% CuO, and 6wt% RuO.

[0066] Preparation Example 3

[0067] The preparation was carried out in the same manner as in Preparation Example 1, except that the activated carbon was changed to: 20 wt % coal-based activated carbon, 0 wt % coconut shell activated carbon and 0 wt % fruit shell activated carbon.

[0068] Preparation Example 4

[0069] The preparation was carried out in the same manner as in Preparation Example 1, except that the active components were changed to: 5wt% of MnO, 3wt% of NiO, 5wt% of CoO, and 7wt% of CeO.

[0070] Preparation Example 5

[0071] The preparation method was carried out in the same manner as in Preparation Example 1, except that: molecular sieve 40wt%, coal-based activated carbon 10wt%, coconut shell activated carbon 11wt%, fruit shell activated carbon 11wt%, Fe2O3 7wt%, CuO 7wt%, RuO7wt%, and ZnO 7wt%.

[0072] The appearance of the catalysts obtained in the above-mentioned preparation examples 1-5 is as follows: Figure 2 As shown, they are all cylindrical and have 6 through holes. The SEM scanning image of the catalyst prepared in Preparation Example 1 is as shown in Figure 3 As shown, it can be seen that the prepared catalyst has many internal voids and the voids are evenly distributed.

[0073] Preparation Example 1-1

[0074] The preparation was carried out in the same manner as in Preparation Example 1, except that the molding in step ③ was not performed and the obtained catalyst did not contain through holes.

[0075] Preparation Example 1-2

[0076] The preparation was carried out in the manner of Preparation Example 1, except that the catalyst only included a carrier and an active component, and the contents were: molecular sieve 80wt%, Fe2O3 5wt%, CuO 3wt%, RuO 5wt%, and ZnO 7wt%.

[0077] Preparation Example 1-3

[0078] The preparation was carried out in the same manner as in Example 1, except that the active components were changed to: 5 wt% Fe(NO3)3, 3 wt% Cu(NO3)2, and N4O 10 5wt% of Ru and 7wt% of Zn(NO3)2·6H2O.

[0079] Preparation Example 1-4

[0080] The preparation method was carried out in the same manner as in Preparation Example 1, except that the curing step was not performed in the preparation method.

[0081] Preparation Example 1-5

[0082] The preparation was carried out in the same manner as in Preparation Example 1, with the only difference being that the catalyst carrier was spherical Al2O3.

[0083] The properties of the catalysts prepared in the above preparation examples are shown in Table 1.

[0084] Table 1 Catalyst performance

[0085]

[0086]

[0087] Examples 1-5 are based on the catalysts prepared in Preparation Examples 1-5 to treat wastewater 1, and Examples 6 and 7 are based on the catalyst prepared in Preparation Example 1 to treat wastewaters 2 and 3 to be treated, respectively. The filling rates of the catalysts in the above examples are all 30%. In the oxidation reactor 7, the amount of ozone is 50 mg / L, and the wastewater residence time is 30 min. In the catalytic reactor 19, the amount of ozone is 100 mg / L, and the residence time is 60 min.

[0088] Comparative Examples 1-5 are respectively based on the treatment of wastewater 1 with the catalysts prepared in Preparation Examples 1-1 to 1-5, the filling rate of the catalyst is 30%, the amount of ozone in the oxidation reactor 7 is 50 mg / L, and the wastewater residence time is 30 min, and the amount of ozone in the catalytic reactor 19 is 150 mg / L, and the residence time is 90 min.

[0089] Comparative Example 6

[0090] The method of Example 1 is followed, except that the wastewater enters the catalytic reactor 19 directly without passing through the pre-treatment unit, the wastewater treatment residence time is 90 minutes, and the ozone dosage is 150 mg / L.

[0091] The COD, TOC and chromaticity of the wastewater 1 to be treated are 220 mg / L, 85 mg / L and 280 respectively.

[0092] The COD, TOC and chromaticity of the wastewater 2 to be treated are 130 mg / L, 50 mg / L and 320 respectively.

[0093] The COD, TOC and chromaticity of the wastewater 3 to be treated are 500 mg / L, 200 mg / L and 400 respectively.

[0094] The results of the above embodiments and comparative examples are shown in Table 2.

[0095] Table 2 Wastewater treatment results

[0096]

[0097]

[0098] From the above results, it can be seen that the system and method provided by the present invention have good removal effects on COD, TOC and chromaticity in wastewater, and also have good treatment effects on wastewater with COD up to 500 mg / L, TOD up to 200 mg / L, and chromaticity up to 400. However, the treatment effects of comparative examples 1-5 on wastewater are obviously inferior to those of the method provided by the present invention due to catalyst reasons. In comparative example 6, since the wastewater has not been pre-treated, although the catalyst still uses the catalyst provided by the present invention, the treatment effect is still not ideal.

[0099] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An ozone catalytic oxidation wastewater treatment device, It is characterized in that The treatment device comprises: a pre-treatment unit and a catalytic reactor, wherein the drain outlet of the pre-treatment unit is connected to the catalytic water inlet of the catalytic reactor, the catalytic reactor is provided with a catalytic air inlet at the bottom, a catalytic bed is provided therein, the catalytic bed is filled with a catalyst, and the catalytic reactor is also provided with a catalytic water outlet; The catalyst comprises a catalyst carrier, an active component and an adsorption component, the catalyst carrier is a molecular sieve, the active component comprises one or more of oxides of Fe, Ru, Mn, Cu, Ni, Zn, Co, Ce and La, and the adsorption component comprises activated carbon; The catalyst is cylindrical and has through holes inside. The specific surface area of ​​the catalyst is 250-350m 2 / g, pore volume is 0.5-1.5cm 3 / g.

2. The processing device according to claim 1, in, Based on the total amount of the catalyst, the amount of the catalytic carrier is 60-70wt%, the amount of the active component is 10-20wt%, and the amount of the adsorbed component is 15-30wt%; And / or, the activated carbon includes at least two or more of coal-based activated carbon, coconut shell activated carbon and fruit shell activated carbon. Preferably, based on the total amount of the catalyst, the amount of each activated carbon is 5-10wt%.

3. The processing device according to claim 1 or 2, in, The filling rate of the catalyst is 10-50%; And / or, the centerline of the through hole in the catalyst is parallel to the centerline of the catalyst, and the diameter of the through hole is 2-5 mm; And / or, the number of the through holes is 3-7; And / or, the diameter and height of the catalyst are independently 15-25 mm, and the strength of the catalyst is 250-300 N / particle.

4. The processing device according to any one of claims 1 to 3, in, The active component includes Fe 2 O 3 , CuO, RuO and ZnO, based on the total amount of the catalyst, Fe 2 O 3 The amount of CuO is 1-5wt%, the amount of RuO is 3-7wt%, and the amount of ZnO is 5-9wt%.

5. The processing device according to any one of claims 1 to 4, in, The preparation method of the catalyst comprises: grinding the catalytic carrier, the adsorption component and the active component, mixing and molding to obtain a cylindrical precursor, curing and drying the precursor, and then calcining under the protection of an inert gas to obtain the catalyst.

6. The processing device according to claim 5, in, The particle sizes of the catalytic carrier, adsorption component and active component after grinding are independently 300-500 meshes; And / or, the mixing time is 2-4h; And / or, the health-preserving time is 24-48 hours; And / or, the drying temperature is 100-110° C. and the drying time is 4-8 hours; And / or, the calcination temperature is 400-600°C, the time is 2-4h, and the heating rate is 1-2°C.

7. The processing device according to any one of claims 1 to 6, in, The pre-treatment unit comprises: an oxidation reactor, the lower part of which is provided with an oxidation water inlet and an oxidation air inlet, the oxidation air inlet and the catalytic air inlet are connected to an ozone generator at the same time, and the oxidation drain outlet at the upper part of the oxidation reactor is connected to the catalytic water inlet of the catalytic reactor; Preferably, the height of the oxidation drain port is greater than the height of the catalytic drain port of the catalytic reactor; Preferably, the oxidation exhaust port at the top of the oxidation reactor and the catalytic exhaust port at the top of the catalytic reactor are connected to a gas-liquid separator at the same time, and the gas outlet of the gas-liquid separator is connected to a tail gas destroyer.

8. A method for treating wastewater by ozone catalytic oxidation, It is characterized in that The treatment method comprises: contacting the wastewater to be treated with ozone in a catalytic reactor in the treatment device according to any one of claims 1 to 7 for reaction.

9. The processing method according to claim 8, in, In the catalytic reactor, for each liter of the wastewater to be treated, the amount of ozone used is 50-200 mg, and the residence time is 60-120 min; Preferably, the treatment method further comprises: pre-treating the wastewater to be treated, wherein the pre-treatment comprises: pre-oxidizing the wastewater to be treated with ozone in the pre-treatment unit, and then contacting the pre-oxidized wastewater to be treated with ozone in the catalytic reactor for reaction; Wherein, in the pre-treatment unit, for each liter of the wastewater to be treated, the amount of ozone used is 50-100 mg, and the residence time is 30-60 min.

10. The processing method according to claim 8 or 9, in, The wastewater to be treated has a total organic carbon of 70-100 mg / L, a chemical oxygen demand of 200-300 mg / L, and a chromaticity of 260-300.

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