CN119080205A

CN119080205A - Ozone catalytic oxidation wastewater treatment device and method

Info

Publication number: CN119080205A
Application number: CN202411270287.XA
Authority: CN
Inventors: 杨洪新; 李渊博; 姜雪松; 于跃; 马文静; 胡金玲; 杨帅
Original assignee: Sinochem Environmental Technology Engineering Co Ltd
Current assignee: Sinochem Environmental Technology Engineering Co Ltd
Priority date: 2024-09-11
Filing date: 2024-09-11
Publication date: 2024-12-06

Abstract

The invention relates to the field of environmental protection and discloses an ozone catalytic oxidation wastewater treatment device and method, wherein the treatment device comprises a pretreatment unit and a catalytic reactor, wherein the catalytic reactor is filled with a catalyst, the catalyst is cylindrical and is internally provided with a through hole, the specific surface area of the catalyst is 250-350m ²/g, the pore volume is 0.5-1.5cm ³/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 Fe, ru, mn, cu, ni, zn, co, ce and La oxides, the adsorption component comprises active carbon, and the wastewater of the device provided by the invention is contacted with the catalyst after entering the catalytic reactor, so that adsorption reaction occurs, the difficultly degraded pollutants are gathered and effectively adsorbed into pores of the catalyst, the contact time between the adsorbed pollutants and ozone is greatly prolonged, the mass transfer efficiency between the pollutants is effectively improved, and the degradation pollutants in the catalyst and the wastewater are mineralized and decomposed.

Description

Ozone catalytic oxidation wastewater treatment device and method

Technical Field

The invention relates to the field of environmental protection, in particular to an ozone catalytic oxidation wastewater treatment device and method.

Background

Ozone has stronger oxidizing ability and is widely applied to the treatment process of wastewater. Ozone oxidation is mainly realized by two ways of oxidation and catalysis, wherein the oxidation is that ozone and organic matters directly react, the way has stronger selectivity, and generally has good treatment effect on easily degradable pollutants such as unsaturated aliphatic hydrocarbon and the like, the catalysis is that the ozone is decomposed to generate hydroxyl free radicals (OH) which are subjected to oxidation reaction with the pollutants, the way has no selectivity, generally, in order to strengthen the capability of generating the hydroxyl free radicals (OH) by ozone oxidation, an ozone catalyst is generally added in the ozone oxidation process, the ozone catalyst can catalyze the ozone to generate the hydroxyl free radicals (OH), the oxidation capability of a system is greatly enhanced, so that the removal efficiency of the difficultly degradable pollutants is enhanced, the waste water treatment effect is improved, but the existing ozone catalyst has only one overactivity in contact with the catalyst when the catalysis effect is exerted, the retention time is insufficient, the specific surface area of the existing catalyst is smaller, and the three-phase mass transfer effect of solid liquid gas is not high when the catalysis effect is not ideal.

Disclosure of Invention

The invention aims to solve the problems of insufficient contact time between pollutants and a catalyst, small specific surface area of the catalyst, unsatisfactory catalytic effect and the like in the catalysis of an ozone catalyst in the prior art, and provides an ozone catalytic oxidation wastewater treatment device and method.

In order to achieve the aim, the first aspect of the invention provides an ozone catalytic oxidation wastewater treatment device, wherein the treatment device comprises a pretreatment unit and a catalytic reactor, wherein a water outlet of the pretreatment unit is connected with a catalytic water inlet of the catalytic reactor, a catalytic air inlet is arranged at the lower part of the catalytic reactor, a catalytic bed layer is arranged in the catalytic air inlet, a catalyst is filled in the catalytic bed layer, and a catalytic water outlet is also arranged on the catalytic reactor;

The catalyst comprises a catalytic carrier, an active component and an adsorption component, wherein the catalytic carrier is a molecular sieve, the active component comprises one or more of Fe, ru, mn, cu, ni, zn, co, ce and La oxides, and the adsorption component comprises active carbon;

The catalyst is cylindrical, through holes are formed in the catalyst, the specific surface area of the catalyst is 250-350m ²/g, and the pore volume is 0.5-1.5cm ³/g.

In a second aspect, the invention provides a method for treating wastewater by ozone catalytic oxidation, wherein the method comprises the step of carrying out contact reaction of wastewater to be treated with ozone in a catalytic reactor in a treatment device according to the first aspect of the invention.

Through the technical scheme, the wastewater enters the catalytic reactor and then contacts with the catalyst to generate adsorption reaction, the difficultly-degradable pollutants are aggregated and effectively adsorbed in the pores of the catalyst, the ozone generates catalytic reaction under the catalytic action of the catalyst to generate hydroxyl free radicals (OH) with strong oxidability, so that the contact time of the adsorbed pollutants with ozone and the hydroxyl free radicals (OH) is greatly prolonged, the mass transfer efficiency between the adsorbed pollutants is effectively improved, the difficultly-degradable pollutants adsorbed in the catalyst and in the wastewater are mineralized and decomposed, and meanwhile, the solid-liquid-gas three-phase catalytic mass transfer effect is effectively improved due to the fact that the catalyst has a larger specific surface area in the process, and the synergistic effect of the adsorbed pollutants and the catalyst improves the pollutant removal efficiency. The invention has strict conception, reasonable design and good application prospect.

Drawings

FIG. 1 is a schematic diagram of a processing apparatus;

FIG. 2 is an external view of the catalyst prepared in preparation example 1;

FIG. 3 is an electron microscope (SEM) scan of the catalyst prepared in preparation example 1.

Description of the reference numerals

1-Water inlet pool, 2-water inlet pump, 3-oxidation water inlet, 4-oxidation air inlet, 5-oxidation aeration disc, 6-oxidation water distributor, 7-oxidation reactor, 8-oxidation water outlet, 9-oxidation air outlet, 10-first check valve, 11-second check valve, 12-ozone generator, 13-third check valve, 14-catalysis air inlet, 15-catalysis water inlet, 16-catalysis aeration disc, 17-catalysis water distributor, 18-catalysis bed layer, 19-catalysis reactor, 20-catalysis water outlet, 21-catalysis air outlet, 22-water outlet pool, 23-gas-liquid separator and 24-tail gas breaker.

Detailed Description

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

In the description of the present application, it should be understood that the terms "upper," "lower," "vertical," "horizontal," "top," "bottom," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying a number of such features, whereby a feature defining "first," "second," "third," or the like may explicitly or implicitly include one or more such features. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or in communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The invention provides an ozone catalytic oxidation wastewater treatment device, which comprises a pretreatment unit and a catalytic reactor, wherein a water outlet of the pretreatment unit is connected with a catalytic water inlet of the catalytic reactor, a catalytic air inlet is arranged at the lower part of the catalytic reactor, a catalytic bed layer is arranged in the catalytic air inlet, a catalyst is filled in the catalytic bed layer, and a catalytic water outlet is also arranged on the catalytic reactor;

The specific surface area is related to the solid-liquid-gas mass transfer effect of the catalyst, the catalytic effect is directly influenced, and the pore volume influences the adsorption effect of the catalyst on pollutants. The catalyst in the device provided by the invention has larger specific surface area and pore volume, and also has a specific through hole structure, and the catalyst has good adsorption and catalytic capability under the combined action of the specific through hole structure and the specific through hole structure. The specific surface area of the catalyst can be any value in any two value ranges of 250m ²/g、280m²/g、300m²/g、330m²/g、350m²/g, and the pore volume can be any value in any two value ranges of 0.5cm ³/g、0.8cm³/g、1.0cm³/g、1.2cm³/g、1.5cm³/g.

In some embodiments, preferably, the amount of the catalytic support is 60 to 70wt%, the amount of the active component is 10 to 20wt%, and the amount of the adsorbent component is 15 to 30wt%, based on the total amount of the catalyst. The amounts of the carrier, the active component and the adsorption component directly relate to the catalytic adsorption effect, the amount of the catalytic carrier can be any value in any two of the range of 60wt%, 62wt%, 65wt%, 68wt% and 70wt%, the amount of the active component can be any value in any two of the range of 10wt%, 13wt%, 15wt%, 17wt% and 20wt%, and the amount of the adsorption component can be any value in any two of the range of 15wt%, 18wt%, 20wt%, 23wt%, 25wt%, 27wt% and 30wt%, based on the total amount of the catalyst.

In some embodiments, preferably, the activated carbon comprises at least two or more of coal activated carbon, coconut activated carbon, and fruit shell activated carbon. At least two active carbon components are selected to better promote the adsorption effect.

In some embodiments, preferably, the amount of each of the activated carbons is 5 to 10wt% based on the total amount of the catalyst. The amount of each activated carbon may be any value within any two of the range of values 5wt%, 8wt%, 10wt%.

In some embodiments, preferably, the catalyst has a loading of 10 to 50%. The packing fraction refers to the percentage of the volume of catalyst to the volume of space within the catalytic reactor. Compared with the prior art which needs to improve the catalytic effect by means of additional filler, the structure provided by the invention omits filler cost and filling time, and has higher economic value. The filling rate may be any value within any two value ranges of 10%, 20%, 30%, 40%, 50%.

In some embodiments, preferably, the pore axis of the through-holes in the catalyst is parallel to the center line of the catalyst, and the pore diameter of the through-holes is 2-5mm. The invention is provided with the through holes in the catalyst, the through holes can play a synergistic effect with the gaps (pore volume) in the catalyst to obviously increase the mass transfer effect and improve the reaction effect, and the pore diameter of the through holes can be any value in any two numerical ranges of 2mm, 3mm, 4mm and 5mm.

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

In some embodiments, preferably, the diameter and height of the catalyst are each independently 15-25mm, and the strength of the catalyst is 250-300N/particle. The catalyst meeting the requirements of the corresponding diameter and height is taken as one catalyst, the strength of the catalyst directly influences the service life of the catalyst, the strength of the single catalyst is up to more than 250N, the service life is not less than five years, and the strength of the single catalyst can be any value in any two numerical ranges of 260N/particle, 280N/particle and 300N/particle.

In some embodiments, preferably, the active component includes Fe ₂O₃, cuO, ruO, and ZnO, the amount of Fe ₂O₃ 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%, based on the total amount of the catalyst. Fe ₂O₃, cuO, ruO and ZnO are selected as active components, and the catalytic effect can be more effectively improved by matching with a proper quantity ratio relation. The amount of Fe ₂O₃ may be any value in any two of 3wt%, 5wt%, 7wt%, the amount of CuO may be any value in any two of 1wt%, 3wt%, 5wt%, the amount of RuO may be any value in any two of 3wt%, 5wt%, 7wt%, and the amount of ZnO may be any value in any two of 5wt%, 7wt%, 9wt%.

In some embodiments, the preparation method of the catalyst preferably comprises grinding a catalytic carrier, an adsorption component and an active component, mixing and forming to obtain a cylindrical precursor, curing and drying the precursor, and calcining under the protection of inert gas to obtain the catalyst.

In some embodiments, it is preferred that the particle size of the milled catalytic support, the adsorbed component, and the active component are each independently 300-500 mesh. The particle size after grinding may be any value in the range of any two of 300 mesh, 400 mesh, 500 mesh, preferably 350 to 450 mesh.

In some embodiments, preferably, the mixing is for a period of 2-4 hours. The mixing time can be any value in any two value ranges of 2h, 3h and 4h, and is preferably 2.5-3.5h.

In some embodiments, preferably, the time for the maintenance is 24-48 hours. The health time can be any value in any two value ranges of 24h, 30h, 35h, 40h, 44h and 48h, and is preferably 35-40h.

In some embodiments, preferably, the drying is at a temperature of 100-110 ℃ for a time of 4-8 hours. The drying time may be any value within any two value ranges of 4 hours, 6 hours and 8 hours, and is preferably 6 to 8 hours.

In some embodiments, preferably, the calcination is at a temperature of 400-600 ℃ for a time of 2-4 hours at a rate of temperature rise of 1-2 ℃. The calcination temperature may be any value in the range of any two values of 400 ℃, 450 ℃, 500 ℃, 55 ℃ and 600 ℃, preferably 400-500 ℃, and the calcination time may be any value in the range of any two values of 2h, 3h and 4h, preferably 2-3h.

In some embodiments, the pretreatment unit preferably comprises an oxidation reactor, wherein the lower part of the oxidation reactor is provided with an oxidation water inlet and an oxidation air inlet, the oxidation air inlet and the catalytic air inlet are simultaneously connected with an ozone generator, and an oxidation water outlet at the upper part of the oxidation reactor is connected with a catalytic water inlet of the catalytic reactor. By adopting the structure, the wastewater to be treated can firstly enter the oxidation reactor, contact with ozone in the oxidation reactor to perform oxidation reaction, wherein the pollutants which are easy to decompose are decomposed, and the oxidation reaction in the oxidation reactor and the adsorption-catalysis reaction in the catalysis reactor form a synergistic effect, so that the pollutants in the wastewater can be effectively removed.

In some embodiments, preferably, the height of the oxidation vent is greater than the height of the catalytic vent of the catalytic reactor. By adopting the structure, the wastewater in the oxidation reactor automatically flows into the catalytic reactor.

In some embodiments, preferably, the oxidation vent at the top of the oxidation reactor and the catalytic vent at the top of the catalytic reactor are simultaneously connected with a gas-liquid separator, and a gas outlet of the gas-liquid separator is connected with a tail gas destructor. With this structure, the exhausted gas still contains a small amount of ozone, but the concentration of ozone contained in the exhausted gas is very low, and the exhausted gas cannot be returned to the oxidation reactor or the catalytic reactor for continuous use, so the exhausted gas is discharged after treatment.

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

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

In some embodiments, preferably, the amount of ozone used in the pretreatment unit is 50-100mg and the residence time is 30-60min per liter of the wastewater to be treated. For each liter of wastewater to be treated, the ozone consumption can be any value in any two value ranges of 50mg, 60mg, 70mg, 80mg, 90mg and 100mg, and the residence time can be any value in any two value ranges of 30min, 40min, 50min and 60min.

In some embodiments, preferably, the total organic carbon of the wastewater to be treated is 70-100mg/L, the chemical oxygen demand is 200-300mg/L, and the chromaticity is 260-300. The method provided by the method is very suitable for treating wastewater with high difficulty, the Total Organic Carbon (TOC) of the wastewater to be treated can be any value in any two value ranges of 70mg/L, 80mg/L, 90mg/L and 100mg/L, the Chemical Oxygen Demand (COD) can be any value in any two value ranges of 200mg/L, 220mg/L, 240mg/L, 260mg/L, 280mg/L and 300mg/L, and the chromaticity can be any value in any two value ranges of 260, 270, 280, 290 and 300.

The catalyst provided by the invention has a specific surface area of 300-350m ²/g, a pore volume of 1-1.5cm ³/g, based on the total amount of the catalyst, the catalyst carrier is 60-70wt%, the active component is 10-20wt%, and the adsorption component is 15-30wt%, wherein the active carbon comprises coal active carbon, coconut shell active carbon and fruit shell active carbon, the active components comprise Fe ₂O₃, cuO, ruO and ZnO, the amount of Fe ₂O₃ 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%, based on the total amount of the catalyst. The method has good treatment effect on the total organic carbon of 450-550mg/L, the chemical oxygen demand of 150-250mg/L and the chromaticity of 280-320.

The present invention will be described in detail by examples. In the following examples, specific surface area and pore volume were measured by nitrogen adsorption method (specific reference to specific surface area and pore volume measurement in HG/T3927-2020), strength was measured by KQ-3 particle strength meter, TOC, COD and chromaticity were measured by combustion oxidation-non-dispersive infrared absorption method, bichromate method for measuring chemical oxygen demand of water quality (HJ 828-2017) and ISO 7887-1985, test and measurement of water quality color, respectively. The raw materials used in the following preparation examples, examples and comparative examples are commercially available unless otherwise specified.

The following examples and some comparative examples were based on the following ozone catalytic oxidation wastewater treatment apparatus, and the specific structures are as follows:

As shown in fig. 1, the treatment device comprises a pretreatment unit and a catalytic reactor 19, wherein a water outlet of the pretreatment unit is connected with a catalytic water inlet 15 of the catalytic reactor 19, a catalytic air inlet 14 is arranged at the lower part of the catalytic reactor 19, a catalytic bed layer 18 is arranged in the catalytic air inlet, a catalyst is filled in the catalytic bed layer 18, the filling rate of the catalytic bed layer 18 is 10-50%, and a catalytic water outlet 20 is also arranged on the catalytic reactor 19.

The treatment device can also comprise a water inlet system, wherein the water inlet system comprises a water inlet pool 1 and a water inlet pump 2 which are connected in sequence.

The pretreatment unit comprises an oxidation reactor 7, wherein an oxidation water inlet 3 and an oxidation air inlet 4 are arranged at the lower part of the oxidation reactor 7, the oxidation water inlet 3 is connected with the water inlet pump 2, the oxidation air inlet 4 and a catalytic air inlet 14 are simultaneously connected with an ozone generator 12, the ozone generator 12 is connected with a total air supply pipe, a second check valve 11 is arranged on the total air supply pipe, the total air supply pipe is connected with the oxidation air inlet 4 and the catalytic air inlet 14 through a first branch pipe and a second branch pipe respectively, 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.

For increasing the contact of gas and wastewater, an oxidation aeration disc 5 and an oxidation water distributor 6 are arranged at the lower part of the oxidation reactor 7, wherein the oxidation water distributor 6 is connected with the oxidation water inlet 3, the oxidation aeration disc 5 is connected with the oxidation air inlet 4, a catalytic aeration disc 16 and a catalytic water distributor 17 are arranged at the lower part of the catalytic reactor 19, the catalytic aeration disc 16 and the catalytic water distributor 17 are both positioned below the catalytic bed layer 18, wherein the catalytic water distributor 17 is connected with the catalytic water inlet 15, the catalytic aeration disc 16 is connected with the catalytic air inlet 14, an oxidation water outlet 8 at the upper part of the oxidation reactor 7 is connected with the catalytic water inlet 15 at the lower part of the catalytic reactor 19, and the height of the oxidation water outlet 8 is larger than the height of a catalytic water outlet 20 of the catalytic reactor 19.

The highest positions of the first branch pipe and the second branch pipe are higher than the height of the oxidation water outlet 8 and the catalytic water outlet 20, so that waste water is prevented from flowing back into the ozone generator 12 when the operation is stopped.

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 simultaneously connected with a gas-liquid separator 23, a gas outlet of the gas-liquid separator 23 is connected with a tail gas destructor 24, and a catalytic water outlet 20 of the catalytic reactor 19 is connected with a water outlet pool 22.

The oxidation reactor 7 can be of a metal tower body structure or a cement pool structure, and the inside of the oxidation reactor is not filled with filler, so that the oxidation capability of ozone can be fully exerted, ozone enters the oxidation reactor 7 from the oxidation air inlet 4 through the second check valve 11 and the first check valve 10 generated by the ozone generator 12, is uniformly divided into ozone microbubbles under the action of the oxidation aeration disc 5, and the ozone microbubbles and wastewater are fully mixed in the oxidation reactor 7 to perform oxidation reaction.

The catalytic reactor 19 can be of a metal tower body structure, or can be arranged into a cement pool structure, a catalytic bed layer 18 is arranged in the catalytic reactor, hydroxyl radicals (OH) are generated by catalyzing ozone by using a catalyst, effluent water of the oxidation reaction 7 is discharged from an oxidation water outlet 8 and enters the catalytic reactor 19 through a catalytic water inlet 15, waste water is uniformly distributed under the action of a catalytic water distributor 17, ozone is generated by an ozone generator and enters the catalytic reactor 19 through a second check valve 11 and a third check valve 13 through a catalytic air inlet 14, the ozone is uniformly divided into ozone microbubbles under the action of a catalytic aeration disc 16, the ozone microbubbles and the waste water are fully mixed in the catalytic reactor 19 and upwards contact with the catalytic bed layer 18, pollutants in the waste water are firstly adsorbed by the catalyst and are gathered in a catalyst gap, then under the catalysis action, the catalytic reaction is generated, and the ozone is decomposed to generate hydroxyl radicals, so that the pollutants gathered in the aperture of the catalyst and other pollutants in the water are mineralized and decomposed, and the aim of removing the pollutants is fulfilled.

The effluent of the catalytic reactor 19 leaves from the catalytic water outlet 20 and enters into the effluent water pond 22, ozone is discharged from the catalytic air outlet 21 after catalytic reaction, ozone is discharged from the oxidation air outlet 9 after oxidation reaction, the ozone after catalytic reaction and the ozone after oxidation reaction enter into the gas-liquid separator 23 together, and enter into the tail gas destructor 24 after separation, and reach the standard after decomposition and discharge.

Preparation example 1

① Grinding, namely grinding 60wt% of molecular sieve (purchased from Duckweed Cyclobal New materials Co., ltd., model 13X), 5wt% of coal activated carbon, 5wt% of coconut shell activated carbon, 10wt% of fruit shell activated carbon, 5wt% of Fe ₂O₃, 3wt% of CuO, 5wt% of RuO and 7wt% of ZnO based on the total amount of the catalyst, wherein the particle size after grinding reaches 400 meshes, and obtaining a first mixture;

② Mixing, namely adding 20wt% of water into the first mixture (based on the amount of the first mixture), and stirring for 3 hours to obtain a uniform paste;

③ The paste is put into a forming machine for extrusion forming, so as to obtain a cylindrical and porous precursor, wherein the diameter and the height of the precursor are 20mm, the through holes are parallel to the column center line, the aperture is 3mm, and the number of holes is 6;

④ Health preserving, namely, putting the catalyst precursor into a room temperature (about 20 ℃) for health preserving for 36 hours;

⑤ Drying, namely placing the catalyst precursor after the health maintenance into a drying box, wherein the drying temperature is 105 ℃ and the drying time is 6 hours;

⑥ Calcination, namely placing the dried catalyst precursor into a tube furnace (under the protection of inert gas such as nitrogen) and heating to 500 ℃ with a temperature gradient of 1.5 ℃ per minute, and calcining for 3 hours.

Preparation example 2

The process was conducted in the same manner as in preparation example 1 except that 60% by weight of the molecular sieve, 10% by weight of the coal-based activated carbon, 10% by weight of the coconut shell activated carbon, 10% by weight of the fruit shell activated carbon, ₂O₃% by weight of Fe, 1% by weight of CuO and 6% by weight of RuO were conducted.

Preparation example 3

The procedure of preparation example 1 was followed except that the activated carbon was changed to 20% by weight of coal-based activated carbon, and that both of coconut shell activated carbon and fruit shell activated carbon were 0.

Preparation example 4

The procedure of preparation 1 was followed except that the active component was changed to 5% by weight of MnO, 3% by weight of NiO, 5% by weight of CoO and 7% by weight of CeO.

Preparation example 5

The process was conducted in the same manner as in preparation example 1 except that 40% by weight of the molecular sieve, 10% by weight of the coal-based activated carbon, 11% by weight of the coconut shell activated carbon, 11% by weight of the fruit shell activated carbon, ₂O₃% by weight of Fe, 7% by weight of CuO, 7% by weight of RuO, and 7% by weight of ZnO were conducted.

The appearance of the catalysts prepared in preparation examples 1-5 is shown in fig. 2, and the catalysts are all cylindrical and have 6 through holes, wherein the SEM scanning of the catalyst prepared in preparation example 1 is shown in fig. 3, and it can be seen that the prepared catalyst has more internal voids and uniform void distribution.

PREPARATION EXAMPLE 1-1

The procedure was carried out in accordance with preparation example 1, except that molding in step ③ was not carried out, and the catalyst obtained did not contain a through-hole.

PREPARATION EXAMPLES 1-2

The procedure of preparation 1 was followed except that the catalyst consisted of only the carrier and the active components, and the contents were 80wt% of molecular sieve, 80wt% of Fe ₂O₃ wt%, 3wt% of CuO, 5wt% of RuO and 7wt% of ZnO.

Preparation examples 1 to 3

The procedure was followed in preparation example 1, except that the active component was changed to Fe (5 wt% of NO ₃)₃, cu (3 wt% of No ₃)₂, 5wt% of N ₄O₁₀ Ru, and Zn (7 wt% of NO ₃)₂·6H₂ O).

Preparation examples 1 to 4

The procedure was followed as in preparation example 1, except that the preparation method did not undergo a curing step.

Preparation examples 1 to 5

The procedure was carried out in accordance with preparation example 1, except that the catalytic support was spherical Al ₂O₃.

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

TABLE 1 catalyst Performance

Examples 1 to 5 were treatment of wastewater 1 based on the catalysts prepared in preparation examples 1 to 5, examples 6 and 7 were treatment of wastewater 2 and 3 to be treated based on the catalysts prepared in preparation example 1, respectively, the filling ratio of the catalysts of the above examples was 30%, the ozone usage was 50mg/L in the oxidation reactor 7, the wastewater residence time was 30min, and the ozone usage was 100mg/L in the catalytic reactor 19, and the residence time was 60min.

Comparative examples 1 to 5 were treatment of wastewater 1 based on the produced catalysts of production examples 1 to 5, respectively, the catalyst filling rate was 30%, the ozone usage was 50mg/L in the oxidation reactor 7, the wastewater residence time was 30min, and the ozone usage was 150mg/L in the catalytic reactor 19, and the residence time was 90min.

Comparative example 6

The procedure was as in example 1, except that the wastewater was fed directly into the catalytic reactor 19 without the pretreatment unit, the residence time of the wastewater treatment was 90 minutes, and the ozone addition was 150mg/L.

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

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

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

The results of the above examples and comparative examples are shown in Table 2.

TABLE 2 wastewater treatment results

From the results, the system and the method provided by the invention have good removal effect on COD, TOC and chromaticity in the wastewater, and also have good treatment effect on the wastewater with COD up to 500mg/L, TOD up to 200mg/L and chromaticity up to 400. While the treatment effect on the wastewater caused by the catalyst in comparative examples 1 to 5 is obviously inferior to that of the method provided by the invention, the treatment effect is still not ideal in comparative example 6 because the wastewater is not pretreated, and the catalyst is still the catalyst provided by the invention.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. An ozone catalytic oxidation wastewater treatment device, 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, 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;

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 therein. The specific surface area of the catalyst is 250-350 m ² /g and the pore volume is 0.5-1.5 cm ³ /g.

2. The treatment device according to claim 1, wherein, based on the total amount of the catalyst, the amount of the catalyst 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 treatment device according to claim 1 or 2, wherein 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 treatment device according to any one of claims 1-3, wherein the active components include _Fe2O3 , CuO, RuO and ZnO, and 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%.

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

6. The treatment device according to claim 5, wherein 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 treatment device according to any one of claims 1 to 6, wherein the pre-treatment unit comprises: an oxidation reactor, the lower portion of which has an oxidation water inlet and an oxidation air inlet, the oxidation air inlet and the catalytic air inlet are simultaneously connected to an ozone generator, and the oxidation drain outlet at the upper portion 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, characterized in that the 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 treatment method according to claim 8, wherein, 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 treatment method according to claim 8 or 9, wherein 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.