Wastewater treatment device

Abstract

The utility model discloses a wastewater treatment device, the device comprises a cavitation oxidation unit and an oxidation reaction unit communicated with the cavitation oxidation unit, the cavitation oxidation unit utilizes the combination of a hydrodynamic cavitation reactor and an ozone generator to enable ozone oxidation and cavitation oxidation to act synergistically, and the oxidation reaction unit is communicated with the oxidation reaction unit. Substances such as polychlorinated biphenyl and micromolecular carboxylic acid which cannot be thoroughly treated by a wet oxidation reactor are effectively treated, and the effluent quality is improved.

Description

Technical Field

[0001] The utility model belongs to the field of wastewater treatment in environmental engineering, and specifically relates to a wastewater treatment device, which is especially suitable for treating pharmaceutical wastewater with the characteristics of high COD, high toxicity, poor biodegradability and the like. Background Art

[0002] Pharmaceutical wastewater has the characteristics of high COD, high toxicity, and poor biodegradability, making it one of the difficulties in industrial wastewater treatment. The source of pharmaceutical wastewater may be a certain production process, but more commonly it comes from multiple production processes and multiple production lines, and sometimes also includes some experimental production wastewater. After mixing, these wastewaters often contain dozens of various organic solvents, drug intermediates, APIs and other complex components, some of which react with each other to form more difficult-to-degrade substances.

[0003] Wet oxidation (WAO) technology uses oxidizing substances, such as hydrogen peroxide, oxygen or oxygen in the air, to oxidize organic matter in wastewater into carbon dioxide and water under high temperature and high pressure. It has excellent adaptability to highly toxic and difficult-to-degrade organic wastewater. Wet oxidation can completely oxidize most organic matter in wastewater, but it is not ideal for removing some highly toxic organic matter, such as polychlorinated biphenyls and small molecule carboxylic acids, and it is difficult to achieve complete oxidation. Catalysts are used in some WAO reactors to improve the reaction efficiency. This is called catalytic wet oxidation. However, the actual method of adding catalysts is still unable to effectively treat highly toxic pharmaceutical wastewater. Summary of the invention

[0004] 1. Problem to be solved

[0005] Based on the problem that the existing wet oxidation (WAO) technology cannot effectively treat highly toxic pharmaceutical wastewater, the utility model provides a wastewater treatment device, which is particularly suitable for treating pharmaceutical wastewater with the characteristics of high COD, high toxicity, poor biodegradability, etc.

[0006] 2. Technical solution

[0007] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0008] A first aspect of the present invention provides a wastewater treatment device, the device comprising: a cavitation oxidation unit, and an oxidation reaction unit connected to the cavitation oxidation unit;

[0009] The oxidation reaction unit includes a wet oxidation reactor;

[0010] The cavitation oxidation unit includes a hydrodynamic cavitation reactor and a dissolved air cavitator connected to the hydrodynamic cavitation reactor;

[0011] The hydrodynamic cavitation reactor has an input port 1, an output port 1, and a second orifice plate, and the wastewater to be treated is transported to the wet oxidation reactor via the input port 1, the second orifice plate, and the output port 1 of the hydrodynamic cavitation reactor;

[0012] The dissolved air cavitator is used to introduce ozone and / or oxygen into the hydrodynamic cavitation reactor, and is used to introduce the reflux liquid of the oxidation reaction unit into the hydrodynamic cavitation reactor.

[0013] According to any embodiment of the first aspect of the present invention, the dissolved air cavitator is connected to an ozone generator, and the gas generated by the ozone generator is used to introduce ozone and / or oxygen from the dissolved air cavitator into the hydrodynamic cavitation reactor.

[0014] As described herein, the advantages of combining hydrodynamic cavitation and ozone (also known as pre-oxidation) are as follows:

[0015] On the one hand, the hydrodynamic cavitation reaction will produce a thermal effect, causing the interface layer of the outer wall of the cavitation bubble to be in a supercritical state, the properties of water will change, and polar and non-volatile pollutants will be degraded; in addition, the extreme environment produced by hydrodynamic cavitation will cause water molecules to undergo chain and cracking reactions, generating strong oxidizing free radicals, and the oxidation capacity of the system will be enhanced, promoting the removal of volatile pollutants in the bubbles and soluble pollutants in the water;

[0016] On the other hand, the mechanical disturbance produced by the hydrodynamic cavitation reaction will impact the surface of pollutants, promote the breaking of chemical bonds of macromolecular substances and the rupture of microbial cell tissues, and accelerate the degradation rate of pollutants.

[0017] Furthermore, the high-speed turbulence of hydraulic cavitation will improve the ozone mass transfer efficiency, increase the mass transfer of ozone molecules from the gas phase to the water phase, increase the contact opportunity between the oxidant and the pollutants, and improve the ozone utilization rate; ozone gas provides more nuclei for cavity formation, making hydraulic cavitation reactions easier to occur, increasing the cavitation intensity and promoting the formation of more hydroxyl free radicals.

[0018] Therefore, under the extreme environment of high temperature, high pressure and high-speed turbulence formed by hydrodynamic cavitation, ozone decomposes to form active substances such as hydroxyl free radicals and oxygen free radicals, and the oxidation capacity is enhanced.

[0019] Ozone is produced by an ozone generator using pure oxygen. The actual ozone content does not exceed 30% at most. More than 70% of the components introduced into the ozone gas are pure oxygen. Therefore, if only the above-mentioned pre-oxidation process is used, pure oxygen cannot actually be well utilized. The WAO unit just needs oxygen. Based on this, the above-mentioned pre-oxidation is used in conjunction with WAO, which can collect the unused oxygen in the hydraulic cavitation reactor and use it for WAO, which can significantly improve the oxygen utilization rate.

[0020] In addition, the effluent after WAO treatment is separated into gas and water to discharge non-condensable gas, and then the heat is recovered through the heat exchanger. Then part of it is returned to the hydraulic cavitation reactor, and the other part is discharged as effluent to the subsequent treatment unit.

[0021] According to any embodiment of the first aspect of the present invention, the material of the orifice plate 2 can be selected from any one, two or more of polytetrafluoroethylene, ceramic plate, polytetrafluoroethylene lining, and epoxy resin lining, but is not limited thereto.

[0022] According to any embodiment of the first aspect of the present invention, the orifice plate 2 has holes and / or slits, and the area of ​​the holes and / or slits accounts for 10-20% of the area of ​​the same orifice plate 2.

[0023] According to any embodiment of the first aspect of the present invention, the distance between two adjacent orifice plates (122) is 8 to 30% of the height of the hydrodynamic cavitation reactor.

[0024] According to any embodiment of the first aspect of the present invention, the holes on the second orifice plate (122) are elongated slits, and the proportion of the slits to the orifice plate area is between 10-20%.

[0025] According to any embodiment of the first aspect of the present invention, the number of the orifice plates 2 is 3-5.

[0026] As described herein, the number of orifice plates determines the number of cavitation reactions (liquid contraction-cavitation-expansion when passing through the orifice plate is a cavitation reaction), and the thickness and proportion of the orifice plate will affect the flow resistance and cavitation intensity.

[0027] According to any embodiment of the first aspect of the present invention, the spacing ΔH between two adjacent orifice plates is determined by the following empirical formula:

[0028]

[0029] Where:

[0030] H—height of hydrodynamic cavitation reactor (unit: m);

[0031] C—Average COD concentration of the inlet of the wastewater to be treated in the hydrodynamic cavitation reactor (unit: mg / L);

[0032] v—the rising velocity of water flow in the hydrodynamic cavitation reactor (unit: m / s);

[0033] T—average water inlet temperature of the hydrodynamic cavitation reactor ℃;

[0034] k—empirical coefficient value range 1.0-3.0;

[0035] ε—Compensation value range is -0.2 to +0.2.

[0036] Based on the above, if the height of the hydraulic cavitation reactor is 3-5m, the spacing ΔH between two adjacent orifice plates 2 is generally controlled at 0.4-1.5m. At this time, the spacing between two adjacent orifice plates 2 is 8-30% of the height of the hydraulic cavitation reactor. At the same time, the thickness of the orifice plate 2 can be 0.5-1cm.

[0037] In addition, as described herein, factors such as the size and area ratio of the holes and / or slits of the orifice plate 2 will also affect the flow resistance and cavitation intensity.

[0038] Based on the above, if the height of the hydrodynamic cavitation reactor is 3-5m, the spacing ΔH between two adjacent orifice plates 2 is generally controlled to be 0.4-1.5m. At this time, the spacing between two adjacent orifice plates 2 is 8-30% of the height of the hydrodynamic cavitation reactor. At the same time, the thickness of the orifice plate 2 can be 0.5-1cm, the length of the slit can be 5-10cm, and the width can be 0.5-1cm.

[0039] According to any embodiment of the first aspect of the present invention, the oxidation reaction unit includes not only a wet oxidation reactor but also a reflux pipe connected to the wet oxidation reactor; the wet oxidation reactor includes an outlet and an inlet;

[0040] The hydrodynamic cavitation reactor also has a second input port and a second output port;

[0041] The dissolved air cavitator comprises a first dissolved air cavitator and a second dissolved air cavitator.

[0042] According to any embodiment of the first aspect of the present invention, the dissolved air cavitation device 1 is arranged between the input port 2 of the hydrodynamic cavitation reactor and the reflux pipe of the wet oxidation reactor; the dissolved air cavitation device 2 is arranged between the output port 1 of the hydrodynamic cavitation reactor and the inlet of the wet oxidation reactor.

[0043] According to any embodiment of the first aspect of the present invention, the dissolved air cavitator includes an inlet end A, a contraction section B, a throat C, and a diffusion section D, wherein the inlet end A is a liquid input end, the diffusion section is a liquid output end, and a gas flow channel is arranged between the inlet end A and the diffusion section D.

[0044] According to any embodiment of the first aspect of the present invention, the inlet port A of the dissolved air cavitator 1 is connected to the reflux pipe;

[0045] The diffusion section D of the dissolved air cavitation device 1 is connected to the input port 2 of the hydrodynamic cavitation reactor;

[0046] The gas flow channel of the dissolved air cavitator is used for introducing ozone and / or oxygen.

[0047] According to any embodiment of the first aspect of the present invention, the inlet port A of the dissolved air cavitator 2 is connected to the output port 1 of the hydrodynamic cavitation reactor;

[0048] The diffusion section D of the dissolved air cavitator 2 is connected to the inlet of the wet oxidation reactor;

[0049] The gas flow channel of the second dissolved air cavitation device is connected to the second output port of the hydraulic cavitation reactor.

[0050] According to any embodiment of the first aspect of the present invention, the dissolved air cavitation device further comprises a first orifice plate, and the first orifice plate is arranged in the diffusion section D.

[0051] According to any embodiment of the first aspect of the present invention, the holes on the orifice plate 1 are elongated slits, and the proportion of the slits to the area of ​​the orifice plate is between 10-20%.

[0052] Based on the above, if the height of the hydrodynamic cavitation reactor is 3-5m, the spacing ΔH between two adjacent orifice plates 2 is controlled at 0.4-1.5m, the thickness of orifice plate 2 is controlled at 0.5-1cm, the slit length of orifice plate 2 is 5-10cm, and the width is 0.5-1cm, then the thickness of orifice plate 1 can also be controlled at 0.5-1cm, the slit length of orifice plate 1 can be 5-10cm, and the width can be 0.5-1cm.

[0053] According to any embodiment of the first aspect of the present invention, the wastewater treatment device further comprises an exogenous gas supplementer; the exogenous gas supplementer is connected to the gas flow channel of the second dissolved air cavitator.

[0054] According to any embodiment of the first aspect of the present invention, the oxidation reaction unit further comprises a water separator in communication with the outlet of the wet oxidation reactor, and a heat exchanger in communication with the water separator;

[0055] The heat exchanger is in communication with the return pipe.

[0056] The specific steps of treating wastewater with the device provided in any embodiment of the first aspect of the present invention include:

[0057] Passing the water to be treated into a hydrodynamic cavitation reactor;

[0058] Passing ozone and / or oxygen into the hydrodynamic cavitation reactor through a dissolved air cavitator;

[0059] Passing the water treated by the hydrodynamic cavitation reactor into a wet oxidation reactor;

[0060] Wherein, the water body to be treated includes:

[0061] The wastewater to be treated is introduced into the hydrodynamic cavitation reactor; and

[0062] The reflux liquid introduced into the hydrodynamic cavitation reactor is the treated effluent of the wet oxidation reactor.

[0063] According to any embodiment of the second aspect of the present invention, ozone and / or oxygen is introduced into the water body treated by the hydrodynamic cavitation reactor through the dissolved air cavitation device.

[0064] Furthermore, the water treated by the hydrodynamic cavitation reactor is introduced into the wet oxidation reactor through a dissolved air cavitator.

[0065] Further, the dissolved air cavitation device comprises a dissolved air cavitation device 1 and a dissolved air cavitation device 2;

[0066] Passing ozone and / or oxygen into the hydrodynamic cavitation reactor through a dissolved air cavitator;

[0067] Passing the reflux liquid of the wet oxidation reactor into the hydrodynamic cavitation reactor through a dissolved air cavitator;

[0068] Passing ozone and / or oxygen into the water body treated by the two-way hydraulic cavitation reactor of the dissolved air cavitation device;

[0069] The water treated by the hydraulic cavitation reactor is introduced into the wet oxidation reactor through the dissolved air cavitator 2.

[0070] Furthermore, the temperature of the reflux liquid is ≤40°C.

[0071] Furthermore, the temperature of the reflux liquid is controlled to be ≤40°C by the heat exchanger.

[0072] Furthermore, the water volume ratio of the reflux liquid introduced into the hydrodynamic cavitation reactor to the wastewater to be treated introduced into the hydrodynamic cavitation reactor is 0.5-2.0.

[0073] Furthermore, the hydraulic retention time of the water to be treated in the hydrodynamic cavitation reactor is 0.5-4 hours;

[0074] The water body to be treated mentioned herein includes the wastewater to be treated introduced into the hydrodynamic cavitation reactor, and the reflux liquid introduced into the hydrodynamic cavitation reactor.

[0075] Furthermore, the ratio of the gas flow rate introduced into the hydrodynamic cavitation reactor to the flow rate of the water body to be treated introduced into the hydrodynamic cavitation reactor is 0.15-0.6;

[0076] The water body to be treated mentioned herein includes the wastewater to be treated introduced into the hydrodynamic cavitation reactor, and the reflux liquid introduced into the hydrodynamic cavitation reactor.

[0077] Furthermore, the water body to be treated is pharmaceutical wastewater, the COD of the water body is 20000-200000 mg / L, and contains dimethylformamide, dichloromethane, triethylamine, tetrahydrofuran, tertiary methyl ether, polychlorinated biphenyls, nitrobenzene, toluene and other substances.

[0078] Beneficial Effects

[0079] (1) The wastewater treatment device provided by the utility model includes a cavitation oxidation unit and an oxidation reaction unit connected to the cavitation oxidation unit. The cavitation oxidation unit uses a hydraulic cavitation reactor and an ozone generator in combination to achieve synergistic effects of ozone oxidation and cavitation oxidation, effectively treating substances such as polychlorinated biphenyls and small molecular carboxylic acids that cannot be thoroughly treated by a wet oxidation reactor, thereby improving the quality of effluent water.

[0080] The hydraulic cavitation reactor and the ozone generator are used together to realize the pre-oxidation step of the combined action of ozone oxidation and hydraulic cavitation, which pre-oxidizes the wastewater to be treated without introducing solid phase matter and secondary pollution, is conducive to the subsequent wet oxidation reaction, and can effectively reduce the hydraulic residence time and reaction condition requirements of the wet oxidation reaction.

[0081] (3) In the stage of combined hydrodynamic cavitation reaction and ozone (also known as pre-oxidation), the underutilized ozone and oxygen can enter the wet oxidation reactor and continue to be fully utilized, thereby improving the oxygen utilization rate and saving the need for ozone tail gas treatment.

[0082] (4) The parameters of the cavitation oxidation unit are easy to adjust, while the adjustment cost of the oxidation reaction unit (especially the wet oxidation reaction) is relatively high. The wastewater treatment device or method provided by the utility model has strong adaptability to variable pharmaceutical wastewater. In actual application, according to the increase or decrease of the COD concentration of the wastewater to be treated, adjusting the operating parameters of the cavitation oxidation unit can improve or reduce the oxidation effect and reduce the frequency of parameter adjustment in the wet oxidation reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A schematic diagram of the structure of a wastewater treatment device provided in Example 1 of the utility model;

[0084] Figure 2 A schematic diagram of the structure of a dissolved air cavitator provided in Example 1 of the utility model;

[0085] In the figure: 100, cavitation oxidation unit; 110, dissolved air cavitator 1; A, inlet end; B, contraction section; C, throat; D, diffusion section; 111, orifice plate 1; 112, gas flow channel; 120, hydraulic cavitation reactor; 121, reactor tank; 122, orifice plate 2; 123, input port 1; 124, output port 1; 125, input port 2; 126, output port 2; 130, dissolved air cavitator 2;

[0086] 200. Exogenous gas supplementer;

[0087] 300. Oxidation reaction unit; 310. Wet oxidation reactor; 320. Water separator; 330. Heat exchanger; 340. Reflux pipe. DETAILED DESCRIPTION

[0088] The present disclosure may be more easily understood by reference to the following description in conjunction with examples, all of which constitute a part of the present disclosure. It should be understood that the present disclosure is not limited to the specific products, methods, conditions or parameters described and / or illustrated herein. Further, the terms used herein are only used for the purpose of describing specific embodiments by way of example and are not intended to be limiting unless otherwise indicated.

[0089] It should also be understood that, for the sake of clarity, certain features of the present disclosure may be described herein in the context of separate embodiments, but may also be provided in combination with each other in a single embodiment. That is, unless clearly incompatible or specifically not included, each separate embodiment is considered to be combinable with any other embodiment, and the combination is considered to represent another different embodiment. Conversely, for the sake of simplicity, the various features of the present disclosure described in the context of a single embodiment may also be provided individually or in any sub-combination. Finally, although a particular embodiment may be described as part of a series of steps or part of a more general structure, each step or substructure itself may also be considered to be an independent embodiment.

[0090] Unless otherwise indicated, it should be understood that each individual element in a list and each combination of individual elements in the list will be interpreted as a different embodiment. For example, a list of embodiments represented as "A, B, or C" should be interpreted to include embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B, or C".

[0091] In the present disclosure, the singular forms of the articles "a," "an," and "the" also include the corresponding plural references, and a reference to a specific value includes at least that specific value unless the context clearly indicates otherwise. Thus, for example, a reference to "a substance" is a reference to at least one of that substance and equivalents thereof.

[0092] The terms including ordinal numbers such as "first" and "second" can be used to explain various components or fluids, but these components and fluids are not limited by these terms. Therefore, without departing from the teachings of the present disclosure, these terms are only used to distinguish the component / fluid from another component / fluid.

[0093] When items are described by using the conjunction terms "... and / or...," etc., the description should be understood to include any one of the associated listed items and all combinations of one or more thereof.

[0094] In general, the use of the term "about" indicates an approximate value that may vary depending on the desired properties obtained by the disclosed subject matter, and will be interpreted in a context-dependent manner based on function. Therefore, one of ordinary skill in the art will be able to interpret a certain degree of difference on a case-by-case basis. In some cases, the number of significant figures used when expressing a particular value can be a representative technique for determining the difference allowed by the term "about". In other cases, a gradient in a range of values ​​can be used to determine the range of differences allowed by the term "about". Further, all ranges in this disclosure are inclusive and combinable, and reference to the values ​​stated in the range includes each value within the range.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terms used herein and / or include any and all combinations of one or more of the associated listed items.

[0096] In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if no manufacturer is specified, are all conventional products that can be purchased commercially.

[0097] The present invention is further described below in conjunction with specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. The essential characteristics and remarkable effects of the present invention can be reflected from the following examples, and the described embodiments are part of the embodiments of the present invention, rather than all the embodiments, and therefore, they do not limit the present invention in any way, and those skilled in the art make some non-essential improvements and adjustments based on the content of the present invention, which all belong to the protection scope of the present invention. Specific implementation method 1

[0099] The present invention provides a wastewater treatment device, such as Figure 1 As shown, the device includes a cavitation oxidation unit 100 and an oxidation reaction unit 300;

[0100] The cavitation oxidation unit 100 includes a hydrodynamic cavitation reactor 120 and a dissolved air cavitator connected to the hydrodynamic cavitation reactor 120. The hydrodynamic cavitation reactor 120 has an input port 123 for the wastewater to be treated, an output port 124 after the water body is treated, and an input port 2 125 connected to the dissolved air cavitator; a second orifice plate 122 is provided in the hydrodynamic cavitation reactor 120.

[0101] The oxidation reaction unit 300 includes a wet oxidation reactor 310, which has an inlet and an outlet. The output port 124 of the hydrodynamic cavitation reactor 120 is connected to the inlet of the wet oxidation reactor 310, and the outlet of the wet oxidation reactor 310 is connected to the input port 2 125 of the hydrodynamic cavitation reactor 120.

[0102] Based on this, the wastewater to be treated is transported into the wet oxidation reactor 310 via the input port 123 of the hydraulic cavitation reactor 120, the orifice plate 122, the output port 124, and the inlet of the wet oxidation reactor 310; the dissolved air cavitator introduces gas (including ozone and oxygen) into the hydraulic cavitation reactor 120 via the input port 125 of the hydraulic cavitation reactor 120; and part of the reflux liquid of the wet oxidation reactor 310 will also be introduced into the hydraulic cavitation reactor 120 via the input port 125 of the hydraulic cavitation reactor 120, and the reflux liquid can be achieved by setting a reflux pipe 340 between the outlet of the wet oxidation reactor 310 and the input port 125 of the hydraulic cavitation reactor 120.

[0103] For the dissolved air cavitator, Figure 2 As shown, it includes an inlet end A, a contraction section B, a throat C, a diffusion section D, and an orifice plate 111. The inlet end A is a liquid input end, the diffusion section is a liquid output end, a gas flow channel 112 is arranged between the inlet end A and the diffusion section D, and the orifice plate 111 is arranged in the diffusion section D.

[0104] In some embodiments of the present invention, for the orifice plate 111 and the orifice plate 2 122 (hereinafter referred to as the orifice plate), the orifice plate is an orifice plate with multiple holes or multiple slits, and the area of ​​the holes and / or slits accounts for 10-20% of the area of ​​the same orifice plate. For the orifice plate 2 122 set in the hydraulic cavitation reactor 120, the number (i.e., the number of layers) determines the number of times the cavitation reaction is experienced (the liquid flow contracts-cavitates-expands when passing through the orifice plate, which is a cavitation reaction). Based on this, the number of orifice plates 2 122 set in the hydraulic cavitation reactor 120 is generally 3-5 layers. In addition, the height of the hydraulic cavitation reactor 120 described in the present invention, the spacing ΔH between two adjacent orifice plates 2 122, the orifice plate thickness of the orifice plate 2 122, the size of the holes and / or slits, the area ratio and other factors will affect the flow resistance and cavitation intensity. Based on this, in some embodiments of the present invention, the spacing between two adjacent orifice plates 2 122 is 8-30% of the height of the hydraulic cavitation reactor 120 (such as Figure 1 As shown, the "height of the hydrodynamic cavitation reactor 120" mentioned above specifically refers to the height of the reactor tank 121). Alternatively, the spacing ΔH between two adjacent orifice plates 122 can be determined by the following empirical formula:

[0105]

[0106] Where:

[0107] H—height of the hydrodynamic cavitation reactor (120) (unit: m);

[0108] C—average COD concentration of the inlet of the wastewater to be treated in the hydrodynamic cavitation reactor (120) (unit: mg / L);

[0109] v—the rising velocity of the water flow in the hydrodynamic cavitation reactor (120) (unit: m / s);

[0110] T—average water inlet temperature of the hydrodynamic cavitation reactor (120) °C;

[0111] k—empirical coefficient value range 1.0-3.0;

[0112] ε—Compensation value range is -0.2 to +0.2.

[0113] Based on the above, in some embodiments of the present invention, if the height of the hydrodynamic cavitation reactor 120 is 3-5m, the spacing ΔH between two adjacent orifice plates 122 is generally controlled to be 0.4-1.5m. At this time, the spacing between two adjacent orifice plates 122 is 8-30% of the height of the hydrodynamic cavitation reactor 120. On this basis, if the orifice plate 122 described in the present invention is an orifice plate with multiple slits, the length of the slit can be 5-10cm and the width can be 0.5-1cm. If the orifice plate 1 111 described in the present invention is an orifice plate with multiple slits, the length of the slit can be 5-10cm and the width can be 0.5-1cm.

[0114] In some embodiments of the present invention, the dissolved air cavitator includes a dissolved air cavitator 1 110 and a dissolved air cavitator 2 130; the dissolved air cavitator 1 110 is disposed between the input port 2 125 of the hydrodynamic cavitation reactor 120 and the reflux pipe 340 of the wet oxidation reactor 310; the dissolved air cavitator 2 130 is disposed between the output port 1 124 of the hydrodynamic cavitation reactor 120 and the inlet of the wet oxidation reactor 310. Specifically:

[0115] The inlet end A of the dissolved air cavitator 110 is connected to the reflux pipe 340, the diffusion section D of the dissolved air cavitator 110 is connected to the input port 2 125 of the hydrodynamic cavitation reactor 120, and the gas flow channel 112 of the dissolved air cavitator 110 is used to introduce exogenous ozone and / or oxygen;

[0116] The inlet end A of the dissolved air cavitator 130 is connected to the output port 124 of the hydraulic cavitation reactor 120, the diffusion section D of the dissolved air cavitator 130 is connected to the inlet of the wet oxidation reactor 310, and the gas flow channel 112 of the dissolved air cavitator 130 is connected to the output port 126 of the hydraulic cavitation reactor 120.

[0117] In some embodiments of the present invention, the wastewater treatment device further includes an exogenous gas supplementer 200 , and the exogenous gas supplementer 200 is connected to the gas flow channel 112 of the dissolved air cavitator 130 .

[0118] In some embodiments of the present invention, the oxidation reaction unit 300 further includes a water separator 320 connected to the outlet of the wet oxidation reactor 310 , and a heat exchanger 330 connected to the water separator 320 ; the heat exchanger 330 is connected to the reflux pipe 340 . Specific implementation method 2

[0120] The second embodiment provides a method for treating wastewater, comprising the steps of:

[0121] Passing the wastewater to be treated into the hydrodynamic cavitation reactor 120;

[0122] ozone is introduced into the hydrodynamic cavitation reactor 120 through the dissolved air cavitator 110, and the reflux liquid of the wet oxidation reactor 310 is introduced into the hydrodynamic cavitation reactor 120 at the same time; the water volume ratio of the reflux liquid to the wastewater to be treated introduced into the hydrodynamic cavitation reactor 120 (hereinafter referred to as the reflux ratio) can be 0.5-2.0; and the water body to be treated containing the reflux liquid and the wastewater to be treated has a hydraulic retention time of 0.5-4 hours in the hydrodynamic cavitation reactor 120; the ratio of the gas flow rate introduced into the hydrodynamic cavitation reactor 120 to the flow rate of the water body to be treated introduced into the hydrodynamic cavitation reactor 120 is 0.15-0.6;

[0123] The water treated by the hydrodynamic cavitation reactor 120 is introduced into the wet oxidation reactor 310 through the dissolved air cavitation reactor 130, and the temperature of the reflux liquid is controlled to be ≤40°C through the heat exchanger 330; at the same time, oxygen is supplemented through the dissolved air cavitation reactor 130 through the external gas supplementer 200.

[0124] This specific embodiment provides specific examples 1 to 2 of treating wastewater using the wastewater treatment device of the present invention.

[0125] Example 1

[0126] The wastewater treatment method provided in the second embodiment of the present invention is used to treat the wastewater of a chemical synthesis pharmaceutical factory shown in the following Table 1. The wastewater is the wastewater of a chemical synthesis pharmaceutical factory, which is a mixture of effluents from multiple production workshops and multiple production lines. Since multiple workshops do not produce at the same time, the water quality index varies greatly. The parameters of the incoming water (i.e., the wastewater to be treated) are shown in the following Table 1:

[0127] Table 1:

[0128] Indicator name CODCr(mg / L) NH3-N(mg / L) TN(mg / L) pH (dimensionless) Temperature(℃) Highest value 189000 4000 4500 9.5 35 Minimum value 25000 400 700 7.8 20 Annual average 44000 1300 2000 8.7 28

[0129] The average water flow when the device is running is 3.5m 3 / h, biological toxicity (luminescent bacteria method) is 100%.

[0130] The wastewater treatment device used in this embodiment is as described in the specific implementation mode 1, and more specifically:

[0131] The wastewater treatment device includes a cavitation oxidation unit 100 composed of a dissolved air cavitator 1 110, a hydraulic cavitation reactor 120, and a dissolved air cavitator 2 130; an oxidation reaction unit 300 composed of a wet oxidation reactor 310, a water separator 320, a heat exchanger 330, and a reflux pipe 340; and an exogenous gas supplementer 200 (mainly for supplementing oxygen).

[0132] In addition, the orifice plate 111 and the orifice plate 2 122 in this specific embodiment are both orifice plates with multiple slits, the area of ​​the slits accounts for 20% of the area of ​​the same orifice plate, the size of the slits is 1cm*10cm, and the thickness of the orifice plate is 1cm. In addition, the specific information of the hydrodynamic cavitation reactor 120 is as follows:

[0133] The height of the hydrodynamic cavitation reactor 120 is 5m. On this basis, the treatment effect is further judged through a small test, and the residence time is set to 4h. The average water flow during the operation of the device is 3.5m 3 / h, calculate the radius of the cavitation oxidizer Diameter D=2R=1.88m. Considering the actual project situation, the diameter is taken as 2m.

[0134] Calculate the minimum rising velocity (the reason for using the minimum rising velocity is that high velocity is conducive to the hydraulic cavitation effect, and the most unfavorable situation is considered during design). Take the reflux rate of the reflux liquid as the minimum ratio of 0.5, and the tank water inlet flow rate is 5.25m 3 / h, rising flow rate = water inlet flow / tank cross-sectional area = 1.67m / h.

[0135] The number of layers of the orifice plate 122 is 5, k=2.5, ε=0.15, and the spacing ΔH between two adjacent orifice plates 122 is calculated as follows:

[0136] The amount of ozone added through the dissolved air cavitator 110, the amount of oxygen added through the external gas supplementer 200 through the dissolved air cavitator 130, and the reflux rate of the wet oxidation reactor 310 can be dynamically adjusted according to the effluent conditions of the wet oxidation reactor 310 and the water quality of the incoming water (i.e., the wastewater to be treated).

[0137] In this embodiment 1, the water supply is relatively stable in a typical 7-day 8-hour operation, the reflux ratio of the wet oxidation reactor 310 is controlled to be 0.5, the ozone dosage through the dissolved air cavitator 110 is 5 kg / d, and the flow rate of the air flow generated by the ozone generator (wherein the ratio of ozone to oxygen is about 3:7) is about 10m 3 / d.

[0138] The indicators of the treated water in this embodiment are shown in Table 2 below:

[0139] Table 2:

[0140]

[0141]

[0142] Finally, the COD conversion rate of the treated effluent reached an average of 96%, and the B / C ratio of the treated effluent reached 0.45, which is conducive to subsequent biochemical treatment.

[0143] Example 2

[0144] The wastewater treatment method provided in the second embodiment of the present invention is used to treat the wastewater of a CDMO pharmaceutical company as shown in Table 3 below. The wastewater of a CDMO pharmaceutical company is a mixture of the effluent from the pharmaceutical workshop and the R&D and test wastewater when the company undertakes several orders (different drugs). Due to the changing order types, the wastewater varies greatly. The parameters of the incoming water (i.e., the wastewater to be treated) are shown in Table 3 below:

[0145] Table 3:

[0146] Indicator name CODCr(mg / L) NH3-N(mg / L) TN(mg / L) pH (dimensionless) Temperature(℃) average value 70000 2000 3000 9 20

[0147] The average water flow when the device is running is 0.5m 3 / h, biological toxicity (luminescent bacteria method) is 100%.

[0148] The wastewater treatment device used in this embodiment is as described in the specific implementation mode 1, and more specifically:

[0149] The wastewater treatment device includes a cavitation oxidation unit 100 composed of a dissolved air cavitator 1 110, a hydraulic cavitation reactor 120, and a dissolved air cavitator 2 130; an oxidation reaction unit 300 composed of a wet oxidation reactor 310, a water separator 320, a heat exchanger 330, and a reflux pipe 340; and an exogenous gas supplementer 200 (mainly for supplementing oxygen).

[0150] In addition, the orifice plate 111 and the orifice plate 2 122 in this specific embodiment are both orifice plates with multiple slits, the area of ​​the slits accounts for 10% of the area of ​​the same orifice plate, the size of the slits is 0.5 cm*5 cm, and the thickness of the orifice plate is 0.5 cm. In addition, the specific information of the hydrodynamic cavitation reactor 120 is as follows:

[0151] The height of the hydrodynamic cavitation reactor 120 is 3m. On this basis, the treatment effect is further judged through a small test, and the residence time is set to 2h. The average water flow during the operation of the device is 0.5m 3 / h, calculate the radius of the cavitation oxidizer Diameter D=2R=0.66m. Considering the actual project situation, the diameter is taken as 0.7m.

[0152] Calculate the minimum rising velocity (the reason for using the minimum rising velocity is that high velocity is conducive to the hydraulic cavitation effect, and the most unfavorable situation is considered during design), take the reflux rate of the reflux liquid as the minimum ratio of 0.5, and the water inlet flow rate as 0.75m 3 / h, rising flow rate = water inlet flow / tank cross-sectional area = 1.95m / h.

[0153] The number of layers of the orifice plate 122 is 3, k=3.0, ε=0.15, and the spacing ΔH between two adjacent orifice plates 122 is calculated as follows:

[0154] The amount of ozone added through the dissolved air cavitator 110, the amount of oxygen added through the external gas supplementer 200 through the dissolved air cavitator 130, and the reflux rate of the wet oxidation reactor 310 can be dynamically adjusted according to the effluent conditions of the wet oxidation reactor 310 and the water quality of the incoming water (i.e., the wastewater to be treated).

[0155] In this embodiment 2, the water supply is relatively stable in a typical 7-day 8-hour operation, the reflux ratio of the wet oxidation reactor 310 is controlled to be 100%, the ozone dosage through the dissolved air cavitator 110 is 2 kg / d, and the flow rate of the air flow generated by the ozone generator (wherein the ratio of ozone to oxygen is about 3:7) is about 4 m 3 / d.

[0156] The indicators of the treated effluent in this embodiment are shown in Table 4 below:

[0157] Table 4:

[0158] Average influent COD COD conversion rate Outlet B / C ratio 75323mg / L 92％ 0.41

[0159] Finally, the COD conversion rate of the treated effluent reached an average of 92%, and the B / C ratio of the treated effluent reached 0.41, indicating that the treatment effect was good.

[0160] Comparative Example 1

[0161] In this comparative example, the incoming water (i.e., the wastewater to be treated) as shown in Table 3 is directly introduced into the wet oxidation reactor 310 through the dissolved air cavitator 130, and the temperature of the reflux liquid is controlled by the heat exchanger 330; at the same time, oxygen is supplemented through the dissolved air cavitator 130 by the exogenous gas supplementer 200.

[0162] That is, in this comparative example, only the oxidation reaction unit 300 is processed, and the cavitation oxidation unit (100) is no longer processed. The rest is the same as Example 2.

[0163] The indicators of the treated effluent in this comparative example are shown in Table 5 below:

[0164] Table 5:

[0165] COD conversion rate Outlet B / C ratio 75％ 0.30

[0166] Finally, the COD conversion rate of the treated effluent was 75% on average, and the B / C ratio of the treated effluent was detected to be 0.30.

[0167] Comparative Example 2

[0168] This comparative example is basically the same as Example 2, except that;

[0169] The hydrodynamic cavitation reactor 120 is replaced by a common venturi tube. The specific form and size of the venturi tube are the same as those of the hydrodynamic cavitation reactor 120, but the orifice plate part is eliminated.

[0170] The indicators of the treated effluent in this comparative example are shown in Table 6 below:

[0171] Table 6:

[0172] COD conversion rate Outlet B / C ratio 89％ 0.40

[0173] Finally, the COD conversion rate of the treated water was 89% on average, and the B / C ratio of the treated water was 0.30. Compared with Example 2, the COD conversion rate of the treated water in this comparative example decreased. This is because the use of a venturi tube alone results in a gas-water mixing effect that is not as good as that of a mixer with a perforated plate, and the bubbles of ozone are slightly larger when dissolved, resulting in a slight decrease in utilization. At the same time, the mixing uniformity of the oxygen entering the wet oxidation reactor 310 also decreases, and the utilization rate is also affected.

[0174] Comparative Example 3

[0175] This comparative example is basically the same as Example 2, except that;

[0176] The number of layers of the orifice plate 2 122 is 1, and the rest are the same as in the second embodiment.

[0177] The indicators of the treated effluent in this comparative example are shown in Table 7 below:

[0178] Table 7:

[0179] COD conversion rate Outlet B / C ratio 85％ 0.38

[0180] Finally, the COD conversion rate of the treated water was 85% on average, and the B / C ratio of the treated water was detected to be 0.38. Compared with Example 2, the COD conversion rate of the treated water in this comparative example was significantly reduced. This is because the single-layer orifice plate can only construct a set of contraction zone, cavitation zone, and diffusion zone of the liquid flow, rather than multiple sets of alternating zones, which is not conducive to the formation of cavitation, and the synergistic effect of ozone and cavitation is limited, which reduces the generation of hydroxyl radicals and oxygen radicals.

[0181] Comparative Example 4

[0182] This comparative example is basically the same as Example 2, except that;

[0183] No orifice plate 122 is disposed in the hydrodynamic cavitation reactor 120 , that is, the number of layers of the orifice plate 122 is 0; meanwhile, orifice plate 111 is also disposed in the dissolved air cavitator 1 110 and the dissolved air cavitator 2 130 .

[0184] The rest is the same as Example 2.

[0185] The indicators of the treated effluent in this comparative example are shown in Table 8 below:

[0186] Table 8:

[0187] COD conversion rate Outlet B / C ratio 80％ 0.32

[0188] Finally, the COD conversion rate of the treated effluent was 80% on average, and the B / C ratio of the treated effluent was 0.32. Compared with Example 2, the COD conversion rate of the treated effluent in this comparative example was significantly reduced, and the improvement ability of the effluent B / C ratio was reduced. This is because the removal effect of ozone alone is limited without the synergistic effect of hydrodynamic cavitation.

[0189] Comparative Example 5

[0190] This comparative example is basically the same as Example 2, except that;

[0191] The reflux liquid from the wet oxidation reactor 310 is not introduced into the hydrodynamic cavitation reactor 120 , that is, the reflux ratio is 0%.

[0192] The rest is the same as Example 2.

[0193] The indicators of the treated effluent in this comparative example are shown in Table 9 below:

[0194] Table 9:

[0195] COD conversion rate Outlet B / C ratio 89％ 0.31

[0196] Finally, the COD conversion rate of the treated effluent was 89% on average, and the B / C ratio of the treated effluent was detected to be 0.31. Compared with Example 2, the COD conversion rate of the treated effluent in this comparative example was significantly reduced. This is because the reflux liquid from the wet oxidation reactor 310 to the hydrodynamic cavitation reactor 120 is eliminated, and the flow rate increase caused by the loss of reflux weakens the hydrodynamic cavitation effect to a certain extent. The ability to improve the B / C ratio is weakened because the effluent reflux of the wet oxidation reactor 310 is not further treated, and the biodegradability is not further improved.

[0197] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wastewater treatment device, characterized in that: The device comprises: a cavitation oxidation unit (100), and an oxidation reaction unit (300) connected to the cavitation oxidation unit (100); The oxidation reaction unit (300) includes a wet oxidation reactor (310); The cavitation oxidation unit (100) comprises a hydrodynamic cavitation reactor (120), and a dissolved air cavitator connected to the hydrodynamic cavitation reactor (120); The hydrodynamic cavitation reactor (120) has an input port 1 (123), an output port 1 (124) and a second orifice plate (122), and the wastewater is transported to the wet oxidation reactor (310) via the input port 1 (123), the second orifice plate (122) and the output port 1 (124) of the hydrodynamic cavitation reactor (120); The dissolved air cavitator is used to introduce ozone and / or oxygen into the hydrodynamic cavitation reactor (120), and is used to introduce reflux liquid of the oxidation reaction unit (300) into the hydrodynamic cavitation reactor (120).

2. The wastewater treatment device according to claim 1, characterized in that: The number of the orifice plates 2 (122) is 3 to 5.

3. The wastewater treatment device according to claim 1, characterized in that: The second orifice plate (122) has holes and / or slits, and the area of ​​the holes and / or slits accounts for 10-20% of the area of ​​the same orifice plate (122).

4. The wastewater treatment device according to any one of claims 1 to 3, characterized in that: The distance between two adjacent orifice plates (122) is 8 to 30% of the height of the hydrodynamic cavitation reactor (120).

5. The wastewater treatment device according to any one of claims 1 to 3, characterized in that: The oxidation reaction unit (300) further includes a reflux pipe (340); The reflux pipe (340) is in communication with the wet oxidation reactor (310); The wet oxidation reactor (310) includes an outlet and an inlet; The hydrodynamic cavitation reactor (120) also has a second input port (125) and a second output port (126); The dissolved air cavitator comprises a dissolved air cavitator 1 (110) and a dissolved air cavitator 2 (130).

6. The wastewater treatment device according to claim 5, characterized in that: The dissolved air cavitator 1 (110) is arranged between the input port 2 (125) of the hydraulic cavitation reactor (120) and the reflux pipe (340) of the wet oxidation reactor (310); the dissolved air cavitator 2 (130) is arranged between the output port 1 (124) of the hydraulic cavitation reactor (120) and the inlet of the wet oxidation reactor (310).

7. The wastewater treatment device according to claim 5, characterized in that: The dissolved air cavitator comprises an inlet end A, a contraction section B, a throat C, and a diffusion section D. The inlet end A is a liquid input end, the diffusion section is a liquid output end, and a gas flow channel (112) is provided between the inlet end A and the diffusion section D.

8. The wastewater treatment device according to claim 7, characterized in that: The inlet end A of the dissolved air cavitator 1 (110) is in communication with the return pipe (340); The diffusion section D of the dissolved air cavitation device (110) and the second input port (125) of the hydrodynamic cavitation reactor (120); The gas flow channel (112) of the dissolved air cavitator (110) is used to introduce ozone and / or oxygen.

9. The wastewater treatment device according to claim 7, characterized in that: The inlet port A of the dissolved air cavitator 2 (130) is connected to the outlet port 1 (124) of the hydrodynamic cavitation reactor (120); The diffusion section D of the dissolved air cavitator 2 (130) is connected to the inlet of the wet oxidation reactor (310); The gas flow channel (112) of the second dissolved air cavitation device (130) and the second output port (126) of the hydrodynamic cavitation reactor (120).

10. The wastewater treatment device according to any one of claims 6 to 9, characterized in that: The oxidation reaction unit (300) further includes a water separator (320) in communication with the outlet of the wet oxidation reactor (310), and a heat exchanger (330) in communication with the water separator (320); The heat exchanger (330) is in communication with the return pipe (340).

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