Evaporator and device for simultaneous treatment of VOCs from brine-containing wastewater

Abstract

The application discloses an evaporator and device for evaporating salt-containing wastewater and synchronously treating VOCs, wherein the evaporator comprises a porous film at the top, a three-dimensional porous adsorption film at the bottom, and a light-transmitting side wall at the periphery; the porous film, the three-dimensional porous adsorption film and the light-transmitting side wall form an evaporation chamber of the evaporator; water vapor containing VOCs formed by evaporation of the water body to be treated enters the evaporation chamber of the evaporator through the porous film at the top; on the surface of the three-dimensional porous adsorption film, the VOCs are firmly adsorbed and decomposed under the action of a photocatalyst; the water vapor is captured by a hydrophilic component on the surface of the three-dimensional porous adsorption film, and then evaporates again under the action of light and heat and is discharged out of the evaporation chamber of the evaporator.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of wastewater treatment in environmental engineering, and in particular, relates to an evaporator and device for evaporating salt-containing wastewater and simultaneously treating VOCs. BACKGROUND

[0002] Solar energy is a clean energy that is easy to obtain. Solar-driven evaporation (SE) refers to the use of light-absorbing materials to convert light energy into heat energy in situ and simultaneously heat water bodies to cause evaporation. SE has application potential in industrial water desalination treatment and has advantages in energy saving and emission reduction. In SE technology, there is a wide application prospect in the fields of interfacial evaporation water desalination, salt-containing wastewater treatment, and drinking water supply. Interfacial evaporation refers to the localization of heat energy in a small area of the gas-liquid interface, also known as heat localization, and has high efficiency in evaporation.

[0003] However, high-salt industrial wastewater often contains certain volatile organic compounds (VOCs). After evaporation treatment of the wastewater, the condensed water is generally reused. However, due to the influence of VOCs, the COD index may not meet the reuse requirements. Therefore, the removal of VOCs in the evaporation desalination process is worth attention. As mentioned above, although solar-driven evaporation technology can achieve purification and separation of non-volatile substances and ionic components, during the evaporation process, some substances may volatilize due to heating, especially many industrial wastewater contains a large amount of volatile organic compounds (VOCs). These volatilized substances cannot be properly and effectively treated, and together with water vapor, they pass through the membrane holes to the cold side, condense into distillate when meeting cooling water or cold air, resulting in the inability to obtain high-quality condensed water. SUMMARY

[0004] 1. Problem to be solved

[0005] Based on the problem that the existing solar-driven evaporation technology cannot obtain high-quality condensed water, the present application provides an evaporator and device for evaporating salt-containing wastewater and simultaneously treating VOCs.

[0006] 2. Technical solution

[0007] In order to solve the above problems, the technical scheme adopted by the present application is as follows:

[0008] The present application provides an evaporator for evaporating salt-containing wastewater and simultaneously treating VOCs, which comprises:

[0009] A porous membrane located at the top;

[0010] A three-dimensional porous adsorption membrane located at the bottom;

[0011] A light-transmitting side wall located at the periphery;

[0012] The porous thin film and the three-dimensional porous adsorption film form an evaporation chamber of the evaporator with the light-transmitting side wall;

[0013] The three-dimensional porous adsorption film has a side facing the evaporation chamber and a side facing away from the evaporation chamber;

[0014] The three-dimensional porous adsorption film has a side facing the evaporation chamber and a side facing away from the evaporation chamber;

[0015] The porous thin film has a side facing the evaporation chamber and a side facing away from the evaporation chamber; the side facing away from the evaporation chamber has light-absorbing material;

[0016] The three-dimensional porous adsorption film has a side facing the evaporation chamber and a side facing away from the evaporation chamber; the side facing the evaporation chamber is hydrophilic and has photocatalytic material and light-absorbing material; the side facing away from the evaporation chamber is hydrophobic.

[0017] As described herein, water vapor containing VOCs formed by evaporation of a water body to be treated enters the evaporation chamber of the evaporator via the porous thin film at the top, forms a turbulent flow in the space of the evaporation chamber under the action of a temperature gradient, flows to the three-dimensional porous adsorption film at the bottom, and the VOCs are firmly adsorbed on the surface of the three-dimensional porous adsorption film and decomposed under the action of a photocatalyst, and the water vapor is captured by the hydrophilic component on the surface of the three-dimensional porous adsorption film, and then evaporates again under the action of photothermal effect and is discharged out of the evaporation chamber of the evaporator.

[0018] According to any embodiment of the first aspect of the purpose of the present application, the thickness of the porous thin film is 0.1-2mm.

[0019] According to any embodiment of the first aspect of the purpose of the present application, the pore size of the porous thin film is 0.2-1μm.

[0020] As described herein, the "porous thin film" preferably has a relatively ideal service life, and further has a high light absorption rate, based on which the material of the porous thin film can be any one or both of, for example, a PTFE high polymer porous thin film, a PVDF high polymer porous thin film.

[0021] According to any embodiment of the first aspect of the purpose of the present application, further, to ensure that the "porous thin film" has a high light absorption rate (its light absorption rate is greater than 80%), a light-absorbing material can be coated on its surface (especially the side facing away from the evaporation chamber), based on which the light-absorbing material can be any one or more of, for example, graphite powder, carbon black, carbon nanotubes, graphene.

[0022] In fact, the side of the porous film facing the evaporation chamber is the first source of contact between the evaporation chamber and the water body to be treated, and in order to reduce the damage to the porous film caused by the water body to be treated, it is further desirable that the side of the porous film facing the evaporation chamber also exhibit hydrophobicity to minimize the possibility or degree of corrosion or clogging that the film may suffer.

[0023] According to any embodiment of the first aspect of the object of the present application, the three-dimensional porous adsorption film has a thickness of 0.5-3 cm.

[0024] According to any embodiment of the first aspect of the object of the present application, as described above, in order to ensure that the three-dimensional porous adsorption film has a high light absorption rate (i.e., the light absorption rate is greater than 80%), a light-absorbing material can be coated on the surface of the three-dimensional porous adsorption film, in particular, the side facing the evaporation chamber; based on this, the light-absorbing material can be any one or two or more of, for example, graphite powder, carbon black, carbon nanotubes, graphene.

[0025] According to any embodiment of the first aspect of the object of the present application, the three-dimensional porous adsorption film first has a three-dimensional porous water-permeable skeleton structure, and as described above, in order to ensure that the three-dimensional porous adsorption film has a photocatalytic degradation capability, the three-dimensional porous adsorption film can be subjected to a loading treatment of a photocatalytic material, so that the surface and / or the interior of the three-dimensional porous adsorption film is loaded with a photocatalyst; based on this, the photocatalytic material can be any one or two or more of, for example, TiO2, CeO2, WS2.

[0026] In addition, as described herein, further considering that the three-dimensional porous adsorption film has a certain water absorption, based on this, in combination with the aforementioned thickness requirement (0.5-3 cm), it can both increase the residence time of water vapor containing VOCs, ensure that the VOCs are firmly adsorbed and decomposed under the action of the photocatalyst, and also not reduce the working efficiency of the evaporator. Based on this, the material of the three-dimensional porous adsorption film can be any one or two or more of, for example, melamine sponge, lignocellulose, polypropylene fiber.

[0027] According to any embodiment of the first aspect of the object of the present application, the three-dimensional porous adsorption film has a photocatalytic material and a light-absorbing material, and the mass ratio of the two is (1.5-4):1.

[0028] According to any embodiment of the first aspect of the object of the present application, the working area of the porous film is smaller than the working area of the three-dimensional porous adsorption film.

[0029] As described herein, on the basis of the pore size (0.2-1 μm) of the porous thin film, controlling the water area of the porous thin film to be less than the water area of the three-dimensional porous adsorption film means that the turbulence rhythm of the water vapor containing VOCs can be controlled, and finally the evaporation rate is controlled, ensuring the removal effect of VOCs. On this basis, preferably, the water area of the three-dimensional porous adsorption film is 2-10 times the water area of the porous thin film.

[0030] According to any embodiment of the first aspect of the object of the present application, the distance H between the porous thin film and the three-dimensional porous adsorption film satisfies formula (1):

[0031]

[0032] In the formula:

[0033] H - the distance between the porous thin film and the three-dimensional porous adsorption film, m;

[0034] k1 - an empirical coefficient, with a value range of 0.9-1.1;

[0035] S - the area of the three-dimensional porous adsorption film, m 2 ;

[0036] k2 - an empirical coefficient, with a value range of 0.5-1.5;

[0037] C - the average VOC concentration of the water body to be treated, g / L;

[0038] E - a compensation value, with a value range of -1-1.

[0039] As described herein, the "distance H" is another important factor for controlling the turbulence rhythm of the water vapor containing VOCs, and finally controlling the evaporation rate to ensure the removal effect of VOCs.

[0040] The second aspect of the present application provides a device for evaporating salt-containing wastewater and simultaneously treating VOCs, which comprises:

[0041] An evaporator, which is the evaporator as described in any embodiment of the first aspect of the object of the present application;

[0042] A condenser, which is located below the evaporator and is connected through the three-dimensional porous adsorption film at the bottom of the evaporator.

[0043] According to any embodiment of the second aspect of the object of the present application, the condenser comprises a heat sink and a fan, and the fan is arranged close to the three-dimensional porous adsorption film. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1Structure diagram of the evaporator for evaporating salt-containing wastewater and simultaneously treating VOCs provided for the embodiment 1 of the present application;

[0045] Figure 2 The porous membrane at the top of the evaporator provided for the embodiment 1 of the present application;

[0046] Figure 3 The three-dimensional porous adsorption membrane at the bottom of the evaporator provided for the embodiment 1 of the present application;

[0047] Figure 4 Structure diagram of the device for evaporating salt-containing wastewater and simultaneously treating VOCs provided for the embodiment 1 of the present application;

[0048] Figure 5 The condenser of the device for evaporating salt-containing wastewater and simultaneously treating VOCs provided for the embodiment 1 of the present application;

[0049] In the figure: A, light; B, evaporation direction; C, input of water body to be treated; D, output of condensed water;

[0050] 100, evaporator; 110, porous membrane; 111, lower side of the porous membrane; 112, upper side of the porous membrane; 120, three-dimensional porous adsorption membrane; 121, upper side of the three-dimensional porous adsorption membrane; 122, lower side of the three-dimensional porous adsorption membrane; 130, light-transmitting side wall; 140, evaporation chamber;

[0051] 200, condenser; 210, heat sink; 220, fan. DETAILED DESCRIPTION

[0052] The present disclosure can be more easily understood by reference to the following description in conjunction with the examples included herein. It should be understood that the present disclosure is not limited to the particular products, methods, conditions or parameters described and / or shown herein, all of which can vary. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless otherwise specified.

[0053] It should also be understood that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. That is, each individual embodiment can be combined with any other embodiment or embodiments unless specifically noted otherwise. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any sub-combination. Finally, while the specific embodiments can be described using a series of operations or steps, it will be understood that each of the steps can be performed in any order, and are not necessarily performed consecutively.

[0054] Unless otherwise indicated, it is to be understood that each individual element of a list and every combination of individual elements in that list is to be construed as a different embodiment. For example, a list of embodiments represented as "A, B, or C" is to be construed as including the embodiments of "A," "B," "C," "A or B," "A or C," "B or C," or "A, B, or C."

[0055] In this disclosure, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a substance" is a reference to at least one of such a substance and equivalents thereof.

[0056] Terms including ordinal numbers such as "first" and "second" can be used to explain various components or fluids, but the components, fluids are not limited by the terms. Thus, the terms are used only to distinguish the component / fluid from another component / fluid without departing from the teaching of the disclosure.

[0057] When describing items by using conjunctive terms such as "and / or," etc., the description should be understood to include any one of the associated listed items and all combinations of one or more of them.

[0058] Generally, the use of the term "about" indicates an approximation that can vary depending on the desired characteristics obtained by the disclosed subject matter and will be interpreted based on functionality in a context-dependent manner. Thus, a person of ordinary skill in the art will be able to interpret a degree of difference on a case-by-case basis. In some cases, the number of significant digits used in expressing a particular value can be representative of the degree of precision to which the term "about" allows for variation. In other cases, a range of values in a series can be used to determine the range of variation allowed by the term "about." Further, all ranges in the disclosure are inclusive and combinable, and the mention of a value stated in a range includes each value within the range.

[0059] 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 the present invention belongs; the terminology used herein and / or any and all combinations of one or more related listed items.

[0060] In the following examples, unless otherwise specified, the usual conditions or the conditions recommended by the manufacturer were used. The reagents or instruments used, unless otherwise specified, were all conventional products that can be obtained by commercial purchase.

[0061] The following further describes the present application in conjunction with specific embodiments, but the embodiments do not limit the present application in any form. Unless otherwise specified, the reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field. The essential features and significant effects of the present application can be embodied in the examples described below, which are part of the embodiments of the present application, but not all embodiments. Therefore, they do not limit the present application in any way, and those skilled in the art can make some non-essential improvements and adjustments based on the content of the present application, which are within the scope of protection of the present application.

[0062] Example 1

[0063] The present embodiment provides an evaporator for simultaneous treatment of salt-containing wastewater and VOCs, as shown in Figure 1 The evaporator 100 includes a porous membrane 110 at the top, a three-dimensional porous adsorption membrane 120 at the bottom, and a light-transmitting side wall 130 at the periphery, which encloses the evaporator 100 with the porous membrane 110 and the three-dimensional porous adsorption membrane 120 to form an evaporation chamber 140. The thickness of the three-dimensional porous adsorption membrane 120 is greater than that of the porous membrane 110. The light-transmitting side wall 130 is preferably selected for good light transmission, and in this embodiment, quartz glass is selected. As shown in Figure 2 The porous membrane 110 is coated with a light-absorbing material, so that its light absorption rate under solar spectrum is greater than 80%; the three-dimensional porous adsorption membrane 120 is coated with a light-absorbing material, and the three-dimensional porous adsorption membrane 120 also carries a photocatalytic material. In addition, as shown in Figure 3 The side of the three-dimensional porous adsorption membrane 120 facing the evaporation chamber (hereinafter referred to as the upper side 121 of the three-dimensional porous adsorption membrane) is hydrophilic, and the side facing away from the evaporation chamber (hereinafter referred to as the lower side 122 of the three-dimensional porous adsorption membrane) is hydrophobic. The coating of the light-absorbing material on the porous membrane 110 can be formed and attached to the porous membrane 110 by any existing technology, such as by the method of suction filtration-drying (see Master's Thesis: Lai Qiaoyun. Modification of superhydrophobic membrane and its application in membrane distillation treatment of high-salt wastewater [D]. Guangzhou University, 2023. DOI: 10.27040 / d.cnki.ggzdu.2023.001723, Section 3.2.1 BC@PVDF hydrophobic membrane preparation), or by using a coating containing the adsorbing material.

[0064] The coating or loading of the light-absorbing material and the photocatalytic material on the three-dimensional porous adsorption film 120 can be formed and attached to the porous film 110 by any existing technology, such as immersing the three-dimensional porous adsorption film 120 in a mixed solution containing the light-absorbing material and the photocatalytic material. After soaking, drying is performed to obtain the three-dimensional porous adsorption film 120 with the light-absorbing material and the photocatalytic material. At the same time, a hydrophilic modifier (such as sodium alginate, carboxymethyl cellulose sodium, chitosan, etc.) can be added to the mixed solution to simultaneously complete the hydrophilic modification of the three-dimensional porous adsorption film 120, so that the three-dimensional porous adsorption film 120 obtains a hydrophilic surface. Finally, the lower side 121 of the three-dimensional porous adsorption film is selected for hydrophobic treatment of the surface. A treatment method that can be used for reference is to spray a hydrophobic modifier (such as polydimethylsiloxane, hexadecyltrimethoxysilane, etc.) on the side to form a single-side hydrophobic layer. Specifically, in the embodiment:

[0065] The material of the porous film 110 is a PTFE film with a pore size of 1 mm, a thickness of 2 mm, and an area of 25 cm 2 ; graphite powder is coated on the side of the porous film 110 facing away from the evaporation chamber (hereinafter referred to as the upper side 112 of the porous film, and the side facing the evaporation chamber is hereinafter referred to as the lower side 111 of the porous film), to ensure that the film has an optical absorption rate of greater than 80% under solar spectrum.

[0066] The material of the three-dimensional porous adsorption film 120 is a 0.5 cm thick melamine sponge with an area 9 times (225 cm 2 ) that of the porous film 110; the three-dimensional porous adsorption film 120 is modified as follows:

[0067] (1) TiO2 and graphite powder are added to pure water in a mass ratio of 2.5:1, the mass concentration of graphite powder in the solution is 3 mg / L, and the solution is thoroughly mixed and ultrasonically treated for 30 minutes. Sodium alginate powder is added to make the mass concentration of sodium alginate in the solution reach 1 mg / L, and the solution is thoroughly mixed and ultrasonically treated for 30 minutes to obtain a modified solution;

[0068] (2) The melamine sponge is completely immersed in the modified solution for 5 minutes, and then taken out and placed in a vacuum drying oven at 80°C for 12 hours to obtain a modified melamine sponge;

[0069] (3) Polydimethylsiloxane is sprayed on one side of the modified melamine sponge, and the spraying amount is 1.5 g / m 2 , to form a single-side hydrophobic layer, and finally obtain the three-dimensional porous adsorption film 120 used.

[0070] As to the distance H between the porous film 110 (lower side 111 of the porous film) and the three-dimensional porous adsorption film 120 (upper side 121 of the three-dimensional porous adsorption film), the following calculation is made:

[0071]

[0072] In the formula, k1 is 0.9;

[0073] S is 0.225 m 2 ;

[0074] k2 is 0.5;

[0075] C is

[0076] E is -0.15.

[0077] Based on this, the final distance H between the porous film 110 (lower side 111 of the porous film) and the three-dimensional porous adsorption film 120 (upper side 121 of the three-dimensional porous adsorption film) is

[0078] Based on the above, the present embodiment 1 provides a specific evaporator, which is hereinafter referred to as evaporator-1.

[0079] In addition, the present embodiment also provides the following two evaporators, which are referred to as evaporator-2 and evaporator-3.

[0080] The evaporator-2 is basically the same as the evaporator-1, except that the thickness of the three-dimensional porous adsorption film 120 is 1 cm.

[0081] The evaporator-3 is basically the same as the evaporator-1, except that the thickness of the three-dimensional porous adsorption film 120 is 3 cm.

[0082] Comparative Example 1

[0083] The present comparative example provides the following two comparative evaporators, which are referred to as evaporator-D1 and evaporator-D2.

[0084] The evaporator-D1 is basically the same as the evaporator-1, except that the three-dimensional porous adsorption film 120 used is only modified according to steps (1) and (2) in the embodiment 1, i.e. without the spraying of polydimethylsiloxane in step (3).

[0085] The evaporator-D2 is basically the same as the evaporator-1, except that when the three-dimensional porous adsorption film 120 used is modified according to steps (1) to (3) in the embodiment 1, the sodium alginate powder is not added to the modification solution in step (1) for hydrophilic modification.

[0086] Comparative Example 2

[0087] The present comparative example provides two comparative evaporators, numbered evaporator-D3~evaporator-D5.

[0088] The evaporator-D3 is basically the same as the evaporator-1, the only difference is that the distance H between the porous membrane 110 (the lower side 111 of the porous membrane) and the three-dimensional porous adsorption membrane 120 (the upper side 121 of the three-dimensional porous adsorption membrane) is set to 1 cm.

[0089] The evaporator-D4 is basically the same as the evaporator-1, the only difference is that the distance H between the porous membrane 110 (the lower side 111 of the porous membrane) and the three-dimensional porous adsorption membrane 120 (the upper side 121 of the three-dimensional porous adsorption membrane) is set to 5 cm.

[0090] The evaporator-D5 is basically the same as the evaporator-1, the only difference is that the distance H between the porous membrane 110 (the lower side 111 of the porous membrane) and the three-dimensional porous adsorption membrane 120 (the upper side 121 of the three-dimensional porous adsorption membrane) is set to 15 cm.

[0091] Comparative Example 3

[0092] The present comparative example provides two comparative evaporators, numbered evaporator-D6~evaporator-D7.

[0093] The evaporator-D6 is basically the same as the evaporator-1, the only difference is that the thickness of the three-dimensional porous adsorption membrane 120 is 0.2 cm.

[0094] The evaporator-D7 is basically the same as the evaporator-1, the only difference is that the thickness of the three-dimensional porous adsorption membrane 120 is 5 cm.

[0095] Comparative Example 4

[0096] The present comparative example provides a comparative evaporator, numbered evaporator-D8.

[0097] The evaporator-D8 is basically the same as the evaporator-1, the only difference is that the three-dimensional porous adsorption membrane 120 is a glass fiber membrane without adsorption performance.

[0098] Example 2

[0099] The present example provides an evaporation device, as shown in Figure 4 The evaporation device includes an evaporator 100, and also includes a condenser 200.

[0100] The condenser 200 is located below the evaporator 100 and is connected through the three-dimensional porous adsorption membrane 120 at the bottom of the evaporator 100.

[0101] The condenser 200 is mainly used to condense and collect the water vapor discharged from the three-dimensional porous adsorption film 120 after being treated by the evaporator 100. Therefore, theoretically, the condenser 200 can be selected from any existing form on the market. However, from the perspective of improving the water vapor turbulence effect in the evaporation chamber 140, a condenser with a fan is preferred. As shown in Figure 5 In this embodiment, the condenser 200 includes a shell, and a heat sink 210 and a fan 220 located in the shell. The fan 220 is arranged close to the bottom of the three-dimensional porous adsorption film 120.

[0102] Based on the evaporators 1-3 provided in Example 1, this embodiment forms corresponding evaporation devices 1-3.

[0103] Comparative Example 5

[0104] Based on the evaporators D1-D8 provided in Comparative Examples 1-4, this comparative example forms evaporation devices D1-D8 which are basically the same as those in Example 2.

[0105] Example 3

[0106] In this example, the evaporation devices 1-3 provided in Example 2 and the evaporation devices D1-D7 provided in Comparative Example 5 are used to treat the water body to be treated (a certain chemical high-salinity wastewater). The local sunshine is sufficient, and the average daytime illumination reaches 0.8kw / m 2 The average temperature of the wastewater is 30℃, the total dissolved solids (TDS) is 25000mg / L, the COD is 400mg / L, and the VOCs is 50mg / L, of which the VOCs are mainly phenols. In the continuous 7-day operation of 6 hours per day, the effects before and after treatment are shown in Table 1.

[0107] Table 1:

[0108]

[0109]

[0110] From Table 1, it can be seen that:

[0111] (1) From the evaporation devices 1-3, it can be seen that the water production rate of the three-dimensional porous adsorption film 120 slightly decreases with the increase of the thickness in the range of 0.5-3cm, but the TDS, VOCs and other indicators are not detected, and the removal effect is good.

[0112] Further combining the evaporation device-D6, it can be seen that the thickness of the three-dimensional porous adsorption film 120 is too small, which leads to poor adsorption capacity and a large amount of VOCs penetration, resulting in substandard water production. Further combining the evaporation device-D7, it can be seen that the thickness of the three-dimensional porous adsorption film 120 is too large, which leads to changes in turbulent flow state, increased resistance to steam flow, and reduced evaporation rate.

[0113] (2) Further combining the evaporation device 1 and the evaporation device-D1, it can be seen that the lower side 122 of the three-dimensional porous adsorption film is no longer sprayed with polydimethylsiloxane in step (3), which affects the removal effect of VOCs and significantly reduces the production of condensed water. The reasons are as follows:

[0114] Firstly, the three-dimensional porous adsorption film 120 no longer has a hydrophilic-hydrophobic structure, and both the upper and lower sides are fully hydrophilic, which reduces the effect of thermal localization and slightly reduces the production of condensed water.

[0115] Secondly, the contact interface of the abutting contact area between the evaporator 100 and the condenser 200 changes from hydrophobic to hydrophilic. The hydrophilic contact changes the evaporation-adsorption cycle in this area, which is not conducive to the one-way transport of water vapor from the evaporator 100 area to the condenser 200 area. The stronger the hydrophilicity of the lower side 122 of the three-dimensional porous adsorption film, the faster the part of VOCs carried by the water vapor will transfer into the condenser 200 along the internal channel of the three-dimensional porous adsorption film 120, reducing the residence time of the VOCs in the three-dimensional porous adsorption film 120 and leading to insufficient catalytic degradation.

[0116] (3) Further combining the evaporation device 1 and the evaporation device-D2, it can be seen that the three-dimensional porous adsorption film 120 is no longer hydrophilic, which affects the removal effect of VOCs and slightly reduces the production of condensed water. The reasons are as follows:

[0117] Especially, the decrease in hydrophilicity of the upper side 121 of the three-dimensional porous adsorption film reduces the absorption speed of the three-dimensional porous adsorption film 120 for water vapor in the evaporation chamber 140, and also reduces the adsorption capacity of VOCs, resulting in a decrease in water production rate and water containing VOCs.

[0118] (4) The suction effect of the condenser 200 fan 220 affects the circulation of the airflow. Further combining the evaporation device 1, the evaporation device-D3, and the evaporation device-D4, it can be seen that the distance H between the porous film 110 (the lower side 111 of the porous film) and the three-dimensional porous adsorption film 120 (the upper side 121 of the three-dimensional porous adsorption film) is too small, which leads to a strong influence of the airflow circulation caused by the suction effect of the condenser 200 fan 220 on the evaporation chamber 140, weakens the heat accumulation effect of the evaporation chamber 140, and affects the steam production of the evaporator 100.

[0119] In addition, the temperature of the condenser 200 area is also high under the circulation of the fan, affecting the condensing effect;

[0120] In addition, under the action of air circulation, the contact time of VOCs with the catalyst is greatly reduced, and VOCs directly enter the condensate water, affecting the removal of VOCs.

[0121] As can be seen from the evaporation device 1 and the evaporation device-D5, the distance H between the porous film 110 (the lower side 111 of the porous film) and the three-dimensional porous adsorption film 120 (the upper side 121 of the three-dimensional porous adsorption film) is too large, which will cause the heat storage area to be too large, and the heat circulation under the action of turbulence is difficult to maintain stable, thereby reducing the water production rate.

[0122] (5) As can be seen from the evaporation device 1 and the evaporation device-D8, the body of the three-dimensional porous adsorption film 120 no longer has water absorption, which will affect the water production rate. The body no longer has water absorption, which causes the hydrophilic conveying channel to be reduced. The absorption and transportation of water vapor by the hydrophilic channel composed of modified substances are obviously insufficient, which leads to the decrease of the overall water production rate of the device.

[0123] The above only describes the preferred embodiments of the present application. It should be noted that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. An evaporator for simultaneous treatment of VOCs with brine-containing wastewater, characterized in that, The evaporator comprises: a porous film at the top; a three-dimensional porous adsorption film at the bottom; a light-transmitting side wall at the side; the porous film, the three-dimensional porous adsorption film and the light-transmitting side wall form an evaporation chamber of the evaporator; wherein, the thickness of the three-dimensional porous adsorption film is greater than the thickness of the porous film; the porous film comprises a side facing away from the evaporation chamber, and the side facing away from the evaporation chamber has light-absorbing material; the three-dimensional porous adsorption film comprises a side facing the evaporation chamber and a side facing away from the evaporation chamber, the side facing the evaporation chamber is hydrophilic and has photocatalytic material and light-absorbing material, and the side facing away from the evaporation chamber is hydrophobic; the distance H between the porous film and the three-dimensional porous adsorption film satisfies formula (1): （1） wherein: H is the distance between the porous film and the three-dimensional porous adsorption film, m; k1 is an empirical coefficient, and the value range is 0.9-1.1; S - Area of the three-dimensional porous adsorbing membrane, m 2 ; k2 is an empirical coefficient, and the value range is 0.5-1.5; C is the average VOC concentration of the water body to be treated, g / L; E is a compensation value, and the value range is -1-1.

2. The evaporator of claim 1, wherein, The thickness of the porous film is 0.1-2 mm; The thickness of the three-dimensional porous adsorption film is 0.5-3 cm.

3. The evaporator of claim 1, wherein, The working area of the porous film is smaller than the working area of the three-dimensional porous adsorption film.

4. The evaporator of claim 1, wherein, The working area of the three-dimensional porous adsorption film is 2-10 times the working area of the porous film.

5. The evaporator of any one of claims 1 to 4, wherein the evaporator is configured to evaporate the salt-laden wastewater and the VOCs simultaneously. The porous film is selected from any one or both of a PTFE high polymer porous film and a PVDF high polymer porous film; The material of the three-dimensional porous adsorption film is selected from any one or more than two of melamine sponge, lignocellulose and polypropylene fiber.

6. The evaporator of any one of claims 1 to 4, wherein the evaporator is configured to evaporate the salt-laden wastewater and the VOCs simultaneously. The light-absorbing material is selected from any one or more than two of graphite powder, carbon black, carbon nanotube and graphene; The photocatalytic material is selected from any one or more than two of TiO2, CeO2 and WS2.

7. The evaporator of any one of claims 1 to 4, wherein the evaporator is configured to evaporate the salt-laden wastewater and the VOCs simultaneously. The three-dimensional porous adsorption film has photocatalytic material and light-absorbing material, and the mass ratio of the two is (1.5-4):

1.

8. An apparatus for simultaneous treatment of VOCs with brine wastewater evaporation, characterized in that, The device comprises: an evaporator as claimed in any one of claims 1-7; a condenser located below the evaporator and communicating through the three-dimensional porous adsorption film at the bottom of the evaporator.

9. The apparatus for simultaneous treatment of VOCs with brined wastewater evaporation according to claim 8, characterized in that, The condenser comprises a heat sink and a fan, and the fan is arranged close to the three-dimensional porous adsorption film.

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