Ozone catalytic water treatment device and method with self-power generation and self-filtration

Abstract

The application provides a self-generating self-filtering ozone catalytic water treatment device and method, and belongs to the technical field of sewage treatment equipment, and comprises a cavity, an ozone generating system, an aluminum air battery system, an energy storage system, a self-filtering ozone catalytic material and a water collecting tank. An aeration system is arranged at the bottom of the cavity and is used for ozone aeration. The aluminum air battery system is immersed below the liquid level of the cavity, and the self-filtering ozone catalytic material serves as a cathode material and a water filtering channel. A Y-shaped support layer is arranged at the top of the cavity pool wall, the self-filtering ozone catalytic material is suspended in an inverted U shape on the Y-shaped support layer, and is divided into three parts, i.e., a front part, a middle part and a rear part. The front part is immersed in water, the middle part is higher than the water surface, and the rear part is suspended in the water collecting tank. Through the hydrophilic and hydrophobic characteristics of the self-filtering ozone catalytic material, wastewater pretreatment, solid-liquid separation and self-filtration are realized, ozone and aluminum corrosion products are further promoted to generate ROS, and efficient wastewater treatment is further promoted, and the application is suitable for wastewater treatment of different scales.

Description

TECHNICAL FIELD

[0001] The present application relates to sewage treatment equipment technical field, specifically to a kind of self-generating self-filtering ozone catalytic water treatment device and method. BACKGROUND

[0002] Ozone catalytic technology is one of the wastewater advanced treatment processes, with fast reaction rate, excellent pollutant removal effect, and multiple functions such as disinfection and sterilization and decolorization. However, the traditional ozone catalytic technology has high requirements for SS and suspended solids in water, especially macromolecular colloidal substances directly entering the ozone system will cause problems such as foaming, affecting the stability of the system. Therefore, coagulation, sedimentation, filtration and other processes are needed to pretreat the water quality to a certain extent. SUMMARY

[0003] The present application aims to provide a kind of self-generating self-filtering ozone catalytic water treatment device and method to solve at least one of the technical problems in the above background.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] On the one hand, the present application provides a kind of self-generating self-filtering ozone catalytic water treatment device, which comprises a cavity, an ozone generating system, an aluminum air battery system, an energy storage system, a self-filtering ozone catalytic material and a water collecting tank. The pool body is rectangular, and the bottom is provided with an aeration system for ozone aeration. The aluminum air battery system is immersed in the cavity below the liquid surface by 5-10 cm and located above the aeration system. The cathode material of the aluminum air battery system is composed of self-filtering ozone catalytic material, which also serves as electrode and water filtration channel. A Y-shaped support layer is provided at the top of the pool wall, and the self-filtering ozone catalytic material is suspended in the Y-shaped support layer in an inverted U shape. The self-filtering ozone catalytic material is divided into front, middle and rear parts by the liquid surface and the support layer. The front part of the self-filtering ozone catalytic material is immersed below the liquid surface with the aluminum air battery system, the middle part is higher than and perpendicular to the water surface, the height (5-20 cm) and turning angle (30-45°) of the middle part of the self-filtering ozone catalytic material are controlled, and the rear part of the self-filtering ozone catalytic material is suspended above the upper part of the water collecting tank.

[0006] The aluminum air battery system is composed of double anode single cathode from outside to inside, i.e. plastic clamping plate, aluminum anode, separation material, self-filtering ozone catalytic material, separation material, aluminum anode and plastic clamping plate, which is a sandwich structure of battery assembly. The self-filtering ozone catalytic material serves as cathode, and the anode and cathode are connected through wires and energy storage system to collect the electric energy generated by the aluminum air battery system. The area of the separation material is the same as the apparent area of the aluminum anode, and the apparent area of the self-filtering ozone catalytic material is 2-10 times that of the aluminum anode.

[0007] The self-filtration ozone catalytic material is composed of a porous carbon matrix and an ozone heterogeneous catalytic layer. The matrix is a porous conductive carbon material such as graphite felt, activated carbon felt, carbon cloth, carbon aerogel, etc. The thickness is 0.2 cm-5 cm, and the average pore size is 0.5 μm-5 μm. The catalytic layer is a composite of one or more of Ti, Zn, Co, Mn, Sn, Ce, Al, Fe, Cu metal oxides, and one or more of graphene oxide, oxidized conductive carbon black, oxidized carbon nanotubes, and carbon powder materials doped with elements such as N and S.

[0008] The self-filtration ozone catalytic material is divided into a hydrophilic layer and a hydrophobic layer according to the thickness direction. The inner layer is a hydrophilic layer with a contact angle ranging from 0° to 40°. The surface layer is a hydrophobic layer with a contact angle ranging from 150° to 180°. The inner layer serves as a water flow channel, and the surface layer serves as a gas diffusion layer, promoting the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0009] In a second aspect, the application also provides a method for wastewater treatment using the above-mentioned self-power generation / self-filtration ozone catalytic water treatment device, which comprises:

[0010] (1) Ozone-promoted efficient power generation of aluminum battery and wastewater pretreatment

[0011] High-efficiency power generation: After the wastewater enters the cavity, ozone gas is generated by the ozone generation system and enters the cavity through the bottom aeration system. The ozone concentration ranges from 60 mg / L to 120 mg / L. The aluminum air battery system is immersed below the liquid surface of the cavity. The self-filtration ozone catalytic material serves as the cathode, and the aluminum material serves as the anode. The inorganic salt substances in the wastewater serve as the electrolyte to undergo electrochemical reactions. Under the dual action of ozone and oxygen, the cathode potential is promoted, the aluminum anode corrosion and power generation are accelerated, and the generated electric energy is collected by the energy storage system.

[0012] High-efficiency wastewater pretreatment: The aluminum air battery system generates electricity while producing aluminum corrosion products, such as aluminum ions, which act as excellent ozone homogeneous catalysts, accelerate the decomposition of ozone, and generate a large amount of active oxygen ROS (such as hydroxyl radicals and singlet oxygen), promoting the rapid degradation of refractory substances in the wastewater. On the other hand, the aluminum corrosion products act as flocculants and precipitants to promote the flocculation of macromolecular substances, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions, realizing the efficient synergy of the multifunctional water purification effect of aluminum corrosion products.

[0013] (2) Wastewater self-filtration, ozone in-situ catalysis, and wastewater advanced treatment:

[0014] Solid-liquid autonomous separation and self-filtration: A large amount of aluminum flocculation and sediment produced in the pretreatment process is deposited at the bottom of the cavity under the action of gravity, and small-particle pollutants in the wastewater are filtered at the same time under the internal pore resistance of the self-filtration cathode material, thereby being further purified. On the other hand, the dissolved salt and water molecules in the wastewater further climb upward along the length direction of the filtration perpendicular to the water surface under the capillary action of the cathode material and flow into the rear part of the self-filtration ozone catalytic material through the Y-shaped support layer. Through the above water molecule active mass transfer process and transport process, the wastewater can flow autonomously without any external energy input. Under the condition of gas explosion, the pollutants adhered to the surface of the self-filtration cathode can be cleaned in situ during the ozone gas aeration process, thereby realizing the self-cleaning effect of the surface of the self-filtration ozone catalytic material.

[0015] Ozone in-situ heterogeneous catalysis: During the migration and mass transfer process of the pretreated wastewater in the inner layer of the self-filtration ozone catalytic material, the gas-phase ozone diffuses to the inner layer through the material surface layer, and a large amount of active oxygen ROS is generated on the material surface under the action of the inner layer ozone heterogeneous catalyst, which promotes the catalytic oxidation reaction of the dissolved and soluble organic pollutants in the wastewater.

[0016] Ozone in-situ electrochemical catalysis: During the power generation process of the aluminum-air battery, the self-filtration ozone catalytic material as the cathode will generate a certain external potential. In addition to the above heterogeneous catalysis, the external potential will further accelerate the reduction reaction of ozone and oxygen on the surface layer of the material, generating ozone free radicals, H2O2 and other substances, further promoting the generation of more active oxygen ROS in the ozone catalytic product, and further accelerating the rapid removal of refractory organic matter in the wastewater, so as to realize the efficient synergy of ozone heterogeneous catalysis and electrochemical catalysis of the self-filtration ozone catalytic material.

[0017] Plug flow reaction enhancement of self-filtration material: During the self-filtration ozone catalysis process of the wastewater, the concentration of pollutants in the wastewater gradually decreases along the length direction of the self-filtration ozone catalytic material, so that the self-filtration ozone catalytic material can be regarded as a plug flow, porous electrochemical micro-reaction system in the length direction. Along the length direction, the wastewater only flows in one direction under the action of capillary force and gravity, and finally flows into the water collecting tank, so that the wastewater is difficult to occur back mixing phenomenon, thereby ensuring that the wastewater has a high chemical driving potential in the length direction, which can prevent the wastewater from short-circuiting while ensuring the delivery of high-quality produced water, can withstand the impact caused by the fluctuation of the influent water quality, and finally maintains stable produced water quality.

[0018] The application has the advantages that: without any external energy input, the self-generating process in the high-efficiency sewage purification process can be realized by the aluminum-air battery system, and the energy can be stored, so that the energy-saving and environment-friendly purposes are achieved, and the overall energy utilization efficiency is improved; the organic matters, microorganisms and other pollutants in the sewage can be efficiently oxidized and decomposed, so that the purification effect is further enhanced, and the rapid degradation of the refractory substances in the sewage is promoted; the efficient cooperation of the multifunctional water purification effect of the aluminum corrosion products is realized, the resource transformation and efficient utilization of the waste aluminum materials are realized, and the sustainable, low-carbon and green of the dosing process is realized, the high-quality recycling and regeneration of the aluminum resources are realized; the surface properties of the self-filtration ozone catalytic material are subjected to zoned surface modification treatment in the thickness direction, the inner layer has hydrophilic characteristics, and the surface layer has hydrophobic characteristics, the inner layer serves as a water filtration channel, small particle pollutants in the sewage are filtered through the internal pore channel resistance effect and capillary action, and efficient interface adsorption of the sewage is realized; the surface layer serves as a gas diffusion layer, and promotes the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0019] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0021] Fig. 1 The self-generating / self-filtration ozone catalytic water treatment device structure diagram described in the embodiments of the present application.

[0022] Fig. 2 The principle diagram of the aluminum-air battery system of the self-generating / self-filtration ozone catalytic water treatment device described in the embodiments of the present application.

[0023] Fig. 3 The detailed diagram of the self-filtration front part of the self-generating / self-filtration ozone catalytic water treatment device described in the embodiments of the present application.

[0024] Wherein: 1-cavity; 2-ozone generation system; 3-aluminum-air battery system; 4-energy storage system; 5-self-filtration ozone catalytic material; 6-water collecting tank; 7-aeration system; 8-Y-shaped support layer; 9-plastic splint; 10-aluminum anode; 11-separation material. DETAILED DESCRIPTION

[0025] Embodiments of the present application will be described in detail below with reference to the attached drawings, which are meant to be exemplary and not limiting. The embodiments described below are examples of the present application and are not to be construed as limiting the present application.

[0026] Those skilled in the art will appreciate that unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0027] It should also be understood that terms such as those defined in a generally dictionary are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and can not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0028] Those skilled in the art will appreciate that unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0029] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific 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. Moreover, the specific feature, structure, material or characteristic can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the features of different embodiments or examples described in the specification and the features of different embodiments or examples, without contradiction.

[0030] In the description of the present application, the terms "first", "second" are used only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically defined.

[0031] In the description of the present specification, the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present technology and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present technology.

[0032] Unless otherwise expressly specified and limited, the terms "mount", "connect", "connect", "set" should be understood broadly, for example, it can be fixedly connected, set, or it can be detachably connected, set, or integrally connected, set. For those skilled in the art, the specific meaning of the above terms in the present technology can be understood according to the specific circumstances.

[0033] In order to facilitate the understanding of the present application, the present application will be further explained and described below with specific examples in conjunction with the drawings, and the specific examples do not constitute a limitation on the embodiments of the present application.

[0034] Those skilled in the art should understand that the drawings are only schematic diagrams of the examples, and the components in the drawings are not necessarily necessary for the implementation of the present application.

[0035] In order to overcome the limitations of traditional ozone technology, such as Figs. 1 to 3 As shown, the present application provides a self-power generation / self-filtration ozone catalytic water treatment device and method. Further, a self-filtration ozone system is constructed. First, by combining an aluminum air battery and an ozone catalytic technology, the aluminum battery power generation is realized at the same time, and the aluminum corrosion products are used for wastewater flocculation pretreatment and self-filtration technology for wastewater pump-free autonomous filtration; more importantly, the present application innovatively endows the self-filtration technology with the air cathode and the ozone heterogeneous catalytic properties, by constructing a functional catalytic layer with oxygen reduction and ozone catalysis, using the internal porous, turbulent and plug flow type gas-solid-liquid three-phase reaction system of the self-filtration material, a higher ozone catalytic reaction driving force is provided, the ozone interface reaction is promoted, and the stable effluent is ensured. At the same time, the electric field generated by the battery can provide electrochemical enhancement for the catalyst on the surface of the self-filtration material, further promoting the ozone reduction on the self-filtration cathode material, multiple reactions of oxygen reduction, and without external power supply, all power is derived from the oxidation process of waste aluminum materials, ultimately realizing the ozone catalytic deep water purification process of solid waste treatment wastewater system, the water flow relies on the self-filtration process, without any water pump, achieving automatic water flow, autonomous power generation, autonomous purification, efficient ozone catalysis, solid waste utilization and other multiple low-carbon efficiencies. The efficient purification of wastewater and the recycling of energy are realized, the system not only has high purification efficiency and energy recovery efficiency, but also can effectively remove refractory organic matter and trace pollutants, which has important significance for environmental protection and sustainable development.

[0036] The ozone catalytic water treatment device with self-power generation and self-filtration comprises a cavity, an ozone generation system, an aluminum air battery system, an energy storage system, a self-filtration ozone catalytic material and a water collecting tank. An aeration system is arranged at the bottom of the cavity for ozone aeration. The aluminum air battery system is immersed below the liquid surface in the cavity and located above the aeration system. The cathode material of the aluminum air battery is composed of the self-filtration ozone catalytic material, which simultaneously serves as an electrode and a water filtration channel. A Y-shaped support layer is arranged at the top of the cavity pool wall. The self-filtration ozone catalytic material is suspended in an inverted U shape on the Y-shaped support layer. The self-filtration ozone catalytic material is divided into three parts, i.e., a front part, a middle part and a rear part, along the length direction, with the liquid surface and the Y-shaped support layer as the separation points. The front part is immersed below the water surface with the aluminum air battery, the middle part is higher than and perpendicular to the water surface, and the rear part is suspended above the upper part of the water collecting tank.

[0037] The aluminum air battery system is a battery assembly with a sandwich structure of double anodes and a single cathode. The self-filtration ozone catalytic material is in the middle. The two sides of the self-filtration ozone catalytic material are both sequentially provided with a separation material, an aluminum anode and a plastic clamping plate. The self-filtration ozone catalytic material serves as a cathode. The cathode and the aluminum anode are connected with a wire and an energy storage system, respectively, for collecting generated electric energy. The area of the separation material is the same as the apparent area of the aluminum anode. The apparent area of the self-filtration ozone catalytic material is 2-10 times the area of the aluminum anode.

[0038] The self-filtration ozone catalytic material comprises a porous carbon matrix and an ozone heterogeneous catalytic layer. The porous carbon matrix is a porous conductive carbon material. The porous carbon matrix is graphite felt, activated carbon felt, carbon cloth or carbon aerogel. The thickness of the porous carbon matrix is 0.2 cm-5 cm, and the average pore size is 0.5 μm-5 μm. The catalytic layer is a composite of one or more of Ti, Zn, Co, Mn, Sn, Ce, Al, Fe or Cu metal oxides. The catalytic layer is a composite of one or more of graphene oxide, oxidized conductive carbon black, oxidized carbon nanotubes or carbon powder material doped with N or S elements. According to the thickness direction, the inner layer has a hydrophilic feature with a contact angle ranging from 0° to 40°, and the surface layer has a hydrophobic feature with a contact angle ranging from 150° to 180°. The inner layer serves as a water flow channel, and the surface layer serves as a gas diffusion layer, which promotes the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0039] Example 1

[0040] In this embodiment 1, a self-generating / self-filtering ozone catalytic water treatment device is provided, comprising a cavity 1, an ozone generating system 2, an aluminum air battery system 3, an energy storage system 4, a self-filtering ozone catalytic material 5, a water collecting tank 6; the pool body is rectangular, the bottom is provided with an aeration system 7 for ozone aeration. The aluminum air battery system is immersed in the liquid surface below 8 cm in the cavity, located in the upper part of the aeration system, a Y type support layer 8 is arranged at the top of the cavity pool wall, the self-filtering ozone catalytic material is suspended in the Y type support layer in the form of inverted U, the self-filtering ozone catalytic material is divided into three parts, front, middle and back, with the liquid surface and the support layer as the dividing point. The front part of the self-filtering ozone catalytic material is immersed below the liquid surface with the aluminum air battery system, the middle part is higher than and perpendicular to the water surface, the height of the middle part of the self-filtering ozone catalytic material is controlled to be 10 cm and the turning angle is 30°, and the rear part of the self-filtering ozone catalytic material is suspended to the upper part of the water collecting tank.

[0041] The aluminum air battery system is a sandwich structure battery assembly with double anode and single cathode, the self-filtering ozone catalytic material 5 is in the middle, and the self-filtering ozone catalytic material 5 is provided with a separation material 11, an aluminum anode 10 and a plastic splint 9 in sequence on both sides; wherein the self-filtering ozone catalytic material serves as the cathode. The aluminum air battery system is composed of the plastic splint 9, the aluminum anode 10, the separation material 11, the self-filtering ozone catalytic material 5, the separation material 11, the aluminum anode 10 and the plastic splint 9 from outside to inside, which is a sandwich structure battery assembly with double anode and single cathode, and the anode and the cathode are connected with the energy storage system through wires to collect the electric energy generated by the aluminum air battery system; the area of the separation material is the same as the apparent area of the aluminum anode, and the apparent area of the self-filtering ozone catalytic material is 5 times that of the aluminum anode.

[0042] The self-filtering ozone catalytic material is composed of a porous carbon matrix and an ozone heterogeneous catalytic layer, the matrix is graphite felt with a thickness of 0.2 cm and an average pore diameter of 0.5 μm, and the catalytic layer is graphene oxide.

[0043] The self-filtering ozone catalytic material is divided into a hydrophilic layer and a hydrophobic layer according to the thickness direction; the inner layer of the self-filtering ozone catalytic material is a hydrophilic layer with a contact angle of 25°; the surface layer is a hydrophobic layer with a contact angle of 160°, the inner layer serves as a water flow channel and the surface layer serves as a gas diffusion layer, which promotes the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0044] In this embodiment 1, the above-mentioned self-generating / self-filtering ozone catalytic water treatment device is applied to realize a wastewater treatment method, which comprises:

[0045] (1) Ozone promotes efficient power generation of aluminum battery and wastewater pretreatment

[0046] High-efficiency power generation: After the wastewater enters the cavity, ozone gas is generated by the ozone generation system and enters the cavity through the bottom aeration system, with an ozone concentration range of 90 mg / L; the aluminum-air battery system immersed below the liquid surface of the cavity uses self-filtration ozone catalytic material as the cathode and aluminum material as the anode, and inorganic salt substances in the wastewater as the electrolyte to generate an electrochemical reaction, which, under the dual action of ozone and oxygen, promotes the increase of cathode potential, accelerates aluminum anode corrosion and power generation, and the generated electric energy is collected by the energy storage system.

[0047] High-efficiency wastewater pretreatment: The aluminum-air battery system generates electricity while producing aluminum corrosion products, such as aluminum ions, which act as excellent ozone homogeneous catalysts, accelerate ozone decomposition, and generate a large amount of active oxygen ROS (such as hydroxyl radicals, singlet oxygen, etc.), promoting the rapid degradation of refractory substances in wastewater; on the other hand, aluminum corrosion products act as flocculants and precipitants to promote the flocculation of macromolecular substances, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions in wastewater, achieving efficient synergy of the multifunctional water purification effect of aluminum corrosion products.

[0048] (2) Wastewater self-filtration, in-situ ozone catalysis, and wastewater advanced treatment:

[0049] Solid-liquid self-separation and self-filtration: A large amount of aluminum flocculation and precipitation produced during the pretreatment process is precipitated at the bottom of the cavity under the action of gravity, and small-particle pollutants in the wastewater are filtered at the same time under the size exclusion effect of the self-filtration cathode material, achieving further purification; on the other hand, dissolved salts and water molecules in the wastewater further climb upward along the filter length direction perpendicular to the water surface under the capillary action of the cathode material, and then flow into the back of the self-filtration ozone catalytic material through the Y-shaped support layer; through the above water molecule active mass transfer and transport processes, without any external energy input, wastewater can flow autonomously; under the condition of gas aeration, the pollutants adhering to the surface of the self-filtration cathode can be cleaned in-situ during the ozone gas aeration process, achieving self-cleaning of the surface of the self-filtration ozone catalytic material.

[0050] Ozone in-situ heterogeneous catalysis: During the migration and mass transfer process of pretreated wastewater in the inner layer of the self-filtration ozone catalytic material, gaseous ozone diffuses to the inner layer through the material surface layer, and a large amount of ROS is generated on the material surface under the action of the inner layer ozone heterogeneous catalyst, which catalyzes the oxidation reaction with the flowing wastewater in the inner layer, promoting the oxidation and degradation of refractory and dissolved organic pollutants in the wastewater.

[0051] Ozone in-situ electrochemical catalysis: In the process of generating electricity by aluminum-air battery, the self-filtration ozone catalytic material as the cathode will produce a certain external potential. In addition to the above heterogeneous catalysis, the external potential will further accelerate the reduction reaction of ozone and oxygen on the surface of the material, producing ozone radicals, H2O2 and other substances, further promoting the production of more ROS by ozone catalysis, and further accelerating the rapid removal of refractory organic matter in wastewater, ultimately realizing the efficient synergy of ozone heterogeneous catalysis and electrochemical catalysis of self-filtration ozone catalytic material.

[0052] Plug flow reaction enhancement of self-filtration material: During the self-filtration ozone catalysis process of wastewater, the concentration of pollutants in the wastewater gradually decreases along the length direction of the self-filtration material. Therefore, the self-filtration ozone catalytic material can be regarded as a plug flow, porous electrochemical micro-reaction system along the length direction. Along the length direction, wastewater only flows in one direction under the action of capillary force and gravity, and finally flows into the water collecting tank. Wastewater is difficult to occur back mixing phenomenon, thus ensuring that the wastewater has a high chemical driving potential along the length direction, while preventing wastewater short-circuiting, and can withstand the impact caused by fluctuations in the quality of the influent, ultimately maintaining stable water quality.

[0053] Example 2

[0054] In this embodiment 2, a self-power generation / self-filtration ozone catalytic water treatment device is provided, which comprises a cavity 1, an ozone generation system 2, an aluminum-air battery system 3, an energy storage system 4, a self-filtration ozone catalytic material 5, and a water collecting tank 6. The pool body is rectangular, and an aeration system 7 is arranged at the bottom of the pool body for ozone aeration. The aluminum-air battery system is immersed in the cavity below the liquid surface by 10 cm and is located above the aeration system. A Y-shaped support layer 8 is arranged at the top of the pool wall of the cavity. The self-filtration ozone catalytic material is suspended in the Y-shaped support layer in an inverted U shape. The self-filtration ozone catalytic material is divided into three parts, i.e., front, middle and rear parts, by the liquid surface and the support layer. The front part of the self-filtration ozone catalytic material is immersed below the liquid surface together with the aluminum-air battery system. The middle part of the self-filtration ozone catalytic material is higher than and perpendicular to the water surface. The height of the middle part of the self-filtration ozone catalytic material is controlled to be 15 cm, and the turning angle is controlled to be 45°. The rear part of the self-filtration ozone catalytic material is suspended above the upper part of the water collecting tank.

[0055] The aluminum-air battery system comprises a double-anode single-cathode structure from the outside to the inside, i.e., a plastic clamp plate 9, an aluminum anode 10, a separation material 11, the self-filtration ozone catalytic material 5, the separation material 11, the aluminum anode 10, and the plastic clamp plate 9. The self-filtration ozone catalytic material serves as a cathode. The anode and the cathode are connected to the energy storage system through wires to collect the electric energy generated by the aluminum-air battery system. The area of the separation material is the same as the apparent area of the aluminum anode. The apparent area of the self-filtration ozone catalytic material is 7 times that of the aluminum anode.

[0056] The self-filtration ozone catalytic material is composed of a porous carbon matrix and an ozone heterogeneous catalytic layer, the matrix is graphite felt with a thickness of 1 cm and an average pore diameter of 1 μm, and the catalytic layer is oxidized carbon nanotube.

[0057] The self-filtration ozone catalytic material is divided into a hydrophilic layer and a hydrophobic layer in the thickness direction; the inner layer of the self-filtration ozone catalytic material is the hydrophilic layer with a contact angle of 30°, and the surface layer is the hydrophobic layer with a contact angle of 150°, the inner layer serves as a water flow channel, and the surface layer serves as a gas diffusion layer, which promotes the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0058] In this embodiment 2, a water treatment method using the above-mentioned self-power generation / self-filtration ozone catalytic water treatment device is also provided, the method comprises:

[0059] (1) Ozone-promoted aluminum battery efficient power generation and wastewater pretreatment

[0060] High-efficiency power generation: after the wastewater enters the cavity, ozone gas is generated by the ozone generation system and enters the cavity through the bottom aeration system, the ozone concentration is in the range of 80 mg / L; the aluminum air battery system immersed below the liquid surface of the cavity uses the self-filtration ozone catalytic material as the cathode and the aluminum material as the anode, and the inorganic salt substances in the wastewater as the electrolyte to generate an electrochemical reaction, under the dual action of ozone and oxygen, the cathode potential is promoted, the aluminum anode corrosion and power generation are accelerated, and the generated electric energy is collected by the energy storage system.

[0061] High-efficiency wastewater pretreatment: the aluminum air battery system generates electricity while producing aluminum corrosion products, such as aluminum ions, which act as excellent ozone homogeneous catalysts, accelerate the decomposition of ozone and generate a large amount of ROS (such as hydroxyl radicals, singlet oxygen, etc.), and promote the rapid degradation of refractory substances in the wastewater; on the other hand, the aluminum corrosion products act as flocculants and precipitants to promote the flocculation of macromolecular substances, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions in the wastewater, realizing the efficient synergy of the multifunctional water purification effect of aluminum corrosion products;

[0062] (2) Wastewater self-filtration, ozone in-situ catalysis and wastewater advanced treatment:

[0063] Solid-liquid autonomous separation and self-filtration: A large amount of aluminum flocculation and sediment produced in the pretreatment process, on the one hand, under the action of gravity, precipitates at the bottom of the cavity, and small particle pollutants in the wastewater are filtered at the same time under the internal pore resistance of the self-filtration cathode material, so as to be further purified; on the other hand, the dissolved salt and water molecules in the wastewater further climb upward along the length direction of the filter perpendicular to the water surface under the capillary action of the cathode material, and flow into the back of the self-filtration ozone catalytic material through the Y-shaped support layer; through the above water molecule active mass transfer process and transport process, without any external energy input, the wastewater can be autonomously flowed; under the condition of gas explosion, the pollutants adhered to the surface of the self-filtration cathode can be cleaned in situ during the ozone gas aeration process, and the surface of the self-filtration ozone catalytic material is autonomously cleaned;

[0064] Ozone in-situ heterogeneous catalysis: During the migration and mass transfer process of the pretreated wastewater in the inner layer of the self-filtration ozone catalytic material, the gas-phase ozone diffuses to the inner layer through the material surface layer, and a large amount of ROS is generated on the material surface under the action of the inner layer ozone heterogeneous catalyst, which promotes the catalytic oxidation reaction of the difficult-to-degrade and dissolved organic pollutants in the wastewater;

[0065] Ozone in-situ electrochemical catalysis: During the power generation process of the aluminum-air battery, the self-filtration ozone catalytic material acts as a cathode to generate a certain external potential, in addition to the above-mentioned heterogeneous catalysis, the external potential will further accelerate the reduction reaction of ozone and oxygen on the surface layer of the material, generating substances such as ozone free radicals and H2O2, further promoting the production of more ROS by ozone catalysis, accelerating the rapid removal of refractory organic matter in wastewater, and ultimately realizing the efficient synergy of ozone heterogeneous catalysis and electrochemical catalysis of the self-filtration ozone catalytic material.

[0066] Plug flow reaction enhancement of self-filtration material: During the self-filtration ozone catalysis process of the wastewater, the concentration of pollutants in the wastewater gradually decreases along the length direction of the self-filtration material, so the self-filtration ozone catalytic material can be regarded as a plug flow, porous electrochemical micro-reaction system in the length direction; along the length direction, the wastewater only flows in one direction under the action of capillary force and gravity, and finally flows into the water collecting tank, so the wastewater is difficult to occur back mixing phenomenon, thus ensuring that the wastewater has a high chemical driving potential in the length direction, which can prevent short flow of wastewater, can tolerate the impact caused by the fluctuation of the influent water quality, and finally maintains stable water quality.

[0067] In the embodiment, experiments are performed to treat actual wastewater, and the phosphate in the actual wastewater is 3 mg / L, and the conductivity is 2.81 mS cm -1, turbidity of 25.6 NTU, TOC of 22.05 mg / L, the maximum power density can reach 23.02 mW / g, the maximum mass density is 8.15 mW / g, verify the actual wastewater with conductivity of 2.81 mS cm-1 can drive the battery to generate stable electricity. Turbidity is effectively reduced from 25.6 NTU to 7.9 NTU, COD concentration is 200 mg / L, under room temperature conditions, the reaction time is 1 hour, COD removal rate is more than 70%, heavy metal ion concentration is 50 mg / L, under room temperature, the reaction time is 2 hours, the removal rate is basically more than 60%. Under the maximum power density, the effluent phosphorus concentration gradually decreases with the increase of reaction time. Under different initial pH conditions, electricity can be generated and phosphorus can be removed at the same time, and the removal rate can basically reach more than 80%, under neutral conditions (pH = 7), 90% of phosphorus removal rate can be reached within 1 hour and remain stable. Under weak acidic conditions (pH = 5), 90% of phosphorus removal rate can be reached within 2 hours and remain stable. Under strong alkaline conditions (pH = 11), the battery can achieve the highest 80% of phosphorus removal rate. Therefore, it shows good performance in the treatment of phosphorus removal. At the same time, the ibuprofen removal efficiency is discussed, the initial ibuprofen concentration is 10 mg / L, the room temperature, the reaction time is 1 hour, the ibuprofen removal rate is 90%. The initial fluoride ion concentration is 10 mg / L, the reaction temperature is 25℃, the reaction time is 2 hours, and the fluoride ion removal rate is basically 80%. Finally, after the treatment of the waste water, the phosphorus removal rate is 80%, the fluoride ion removal rate is 70%, the nitrogen removal rate is 90%, the heavy metal ion removal rate is 80%, and the COD removal rate is 85%.

[0068] Example 3

[0069] In this embodiment 3, first provide a self-generating / self-filtering ozone catalytic water treatment device, including cavity 1, ozone generation system 2, aluminum air battery system 3, energy storage system 4, self-filtering ozone catalytic material 5, water collecting tank 6; the pool body is rectangular, the bottom is provided with aeration system 7, which is used for ozone aeration. The aluminum air battery system is immersed in the liquid surface of the cavity by 7 cm, located in the upper part of the aeration system, Y type support layer 8 is arranged at the top of the cavity pool wall, the self-filtering ozone catalytic material is suspended in the Y type support layer in inverted U shape, the self-filtering ozone catalytic material is divided into front, middle and rear three parts with the liquid surface and the support layer as the division point. The front part of the self-filtering ozone catalytic material is immersed below the liquid surface with the aluminum air battery system, the middle part is higher than and perpendicular to the water surface, the height of the middle part of the self-filtering ozone catalytic material is controlled to be 20 cm and the turning angle is 40°, and the rear part of the self-filtering ozone catalytic material is suspended to the upper part of the water collecting tank.

[0070] The aluminum-air battery system is composed of a double-anode single-cathode sandwich structure from outside to inside, i.e., plastic splint 9, aluminum anode 10, separation material 11, self-filtration ozone catalytic material 5, separation material 11, aluminum anode 10, and plastic splint 9; the self-filtration ozone catalytic material serves as a cathode, and the anode and cathode are connected through wires and an energy storage system, respectively, to collect the electric energy generated by the aluminum-air battery system; the area of the separation material is the same as the apparent area of the aluminum anode, and the apparent area of the self-filtration ozone catalytic material is 8 times that of the aluminum anode.

[0071] The self-filtration ozone catalytic material is composed of a porous carbon matrix and an ozone heterogeneous catalytic layer, the matrix is activated carbon felt with a thickness of 0.5 cm and an average pore diameter of 0.5 μm, and the catalytic layer is graphene oxide.

[0072] The self-filtration ozone catalytic material is divided into a hydrophilic layer and a hydrophobic layer according to the thickness direction; the inner layer of the self-filtration ozone catalytic material is a hydrophilic layer with a contact angle of 35°, and the surface layer is a hydrophobic layer with a contact angle of 180°; the inner layer serves as a water flow channel, and the surface layer serves as a gas diffusion layer, thereby promoting the mass transfer of ozone gas on the surface of the porous material and in-situ catalysis.

[0073] In this embodiment 3, a sewage treatment method using the above-mentioned self-power generation / self-filtration ozone catalytic water treatment device is also provided, and the method comprises:

[0074] (1) Ozone-promoted efficient power generation of aluminum battery and wastewater pretreatment

[0075] Efficient power generation: after the wastewater enters the cavity, ozone gas is generated through an ozone generation system and enters the cavity through a bottom aeration system, and the ozone concentration is in the range of 100 mg / L; the aluminum-air battery system is immersed below the liquid surface of the cavity, the self-filtration ozone catalytic material serves as a cathode, and aluminum material serves as an anode; inorganic salt substances in the wastewater serve as electrolytes to undergo electrochemical reactions; under the dual action of ozone and oxygen, the cathode potential is promoted, the corrosion of the aluminum anode is accelerated, and the generated electric energy is collected by the energy storage system.

[0076] Efficient wastewater pretreatment: the aluminum-air battery system generates electricity and produces aluminum corrosion products, such as aluminum ions, which act as excellent ozone homogeneous catalysts to accelerate the decomposition of ozone and generate a large amount of ROS (such as hydroxyl radicals and singlet oxygen), thereby promoting the rapid degradation of refractory substances in the wastewater; on the other hand, the aluminum corrosion products act as flocculants and precipitants to promote the flocculation of macromolecular substances, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions, thereby realizing the efficient synergy of the multifunctional water purification effect of the aluminum corrosion products;

[0077] (2) Wastewater self-filtration, ozone in-situ catalysis, and wastewater advanced treatment:

[0078] Solid-liquid autonomous separation and self-filtration: A large amount of aluminum flocculation and sediment produced in the pretreatment process is precipitated at the bottom of the cavity under the action of gravity, and small-particle pollutants in the wastewater are filtered at the same time under the internal pore resistance of the self-filtration cathode material, thereby being further purified. On the other hand, the dissolved salt and water molecules in the wastewater further climb upward along the length direction of the filtration perpendicular to the water surface under the capillary action of the cathode material and flow into the rear part of the self-filtration ozone catalytic material through the Y-shaped support layer. Through the above water molecule active mass transfer process and transport process, the wastewater can be made to flow autonomously without any external energy input. Under the condition of gas explosion, the pollutants adhered to the surface of the self-filtration cathode can be cleaned in situ during the ozone gas aeration process, thereby realizing the self-cleaning effect of the surface of the self-filtration ozone catalytic material.

[0079] Ozone in-situ heterogeneous catalysis: During the migration and mass transfer process of the pretreated wastewater in the inner layer of the self-filtration ozone catalytic material, the gas-phase ozone diffuses to the inner layer through the material surface layer, and a large amount of ROS is generated on the material surface under the action of the inner layer ozone heterogeneous catalyst, thereby promoting the catalytic oxidation reaction of the difficult-to-degrade and dissolved organic pollutants in the wastewater.

[0080] Ozone in-situ electrochemical catalysis: During the power generation process of the aluminum-air battery, the self-filtration ozone catalytic material acts as a cathode to generate a certain external potential. In addition to the above heterogeneous catalysis, the external potential can further accelerate the reduction reaction of ozone and oxygen on the surface layer of the material, thereby generating ozone free radicals, H2O2 and other substances, further promoting the generation of more ROS of the ozone catalytic product, further accelerating the rapid removal of the difficult-to-degrade organic matter in the wastewater, and finally realizing the efficient synergy of the ozone heterogeneous catalysis and the electrochemical catalysis of the self-filtration ozone catalytic material.

[0081] Plug flow reaction enhancement of self-filtration material: During the self-filtration ozone catalysis process of the wastewater, the pollutant concentration in the wastewater gradually decreases along the length direction of the self-filtration ozone catalytic material. Therefore, the self-filtration ozone catalytic material can be regarded as a plug flow, porous electrochemical micro-reaction system in the length direction. Along the length direction, the wastewater only flows in one direction under the action of capillary force and gravity, and finally flows into the water collecting tank. The wastewater is difficult to be back-mixed, so that the wastewater has a high chemical driving force in the length direction, which can prevent the short flow of the wastewater, tolerate the impact caused by the fluctuation of the inlet water quality, and finally maintain stable water quality.

[0082] In summary, the self-power generation and self-filtration ozone catalytic water treatment device and method have the following advantages:

[0083] 1. Aluminum solid waste and wastewater collaborative utilization and efficient power generation: Through the aluminum-air battery system, the self-filtration ozone catalytic material acts as the cathode, the aluminum material acts as the anode, and the inorganic salt in the wastewater acts as the electrolyte to generate an electrochemical reaction. Under the dual action of ozone and oxygen, the cathode potential is promoted, the corrosion of the aluminum anode is accelerated, and power generation is accelerated, and the energy is collected in the energy storage system. This not only can achieve self-power generation in the process of wastewater purification without any external energy input, but also can achieve self-power generation in the process of wastewater purification through the aluminum-air battery system, and store it to achieve the purpose of energy saving and environmental protection. This energy recovery mechanism not only reduces the energy consumption of the system, but also provides part of the energy to support the wastewater treatment process, improving the overall energy utilization efficiency.

[0084] 2. Efficient wastewater treatment without external chemical agents: Through the electro-ozonolysis effect, the organic matter, microorganisms and other pollutants in the wastewater can be efficiently oxidized and decomposed. Ozone has strong oxidizing property and can rapidly degrade organic matter. Aluminum corrosion products such as aluminum ions generated by aluminum-air battery power generation act as excellent ozone homogeneous catalysts, accelerating the decomposition of ozone and generating a large amount of ROS (such as hydroxyl radicals, singlet oxygen, etc.), further enhancing the purification effect and promoting the rapid degradation of refractory substances in wastewater. On the other hand, aluminum corrosion products can also act as flocculants and precipitants to promote the flocculation of macromolecular substances in wastewater, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions, realizing the efficient synergy of the multifunctional water purification effect of aluminum corrosion products. Through this technology, the resource transformation and efficient utilization of waste aluminum materials are successfully realized, and the sustainable, low-carbon and green process of adding chemicals is also realized. Finally, according to the composition of the aluminum precipitate, it can be reused in other products, thereby realizing the high-quality recycling and regeneration of aluminum resources.

[0085] 3. Multifunctional utilization of self-filtration ozone catalytic material: The self-filtration ozone catalytic material not only acts as the cathode of the aluminum-air battery system, but also as the water filtration channel and gas diffusion layer, realizing multifunctional utilization. The surface characteristics of the self-filtration ozone catalytic material are modified according to the thickness direction, with the inner layer being hydrophilic and the surface layer being hydrophobic. The inner layer acts as a water filtration channel, filtering small particle pollutants in wastewater through internal pore size exclusion and capillary action and achieving efficient interfacial adsorption of wastewater. The surface layer acts as a gas diffusion layer, promoting mass transfer and in-situ catalysis of ozone gas on the surface of the porous material.

[0086] The above describes the specific embodiments of the present application in conjunction with the drawings, but is not a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the disclosed technical solutions of the present application without creative labor should be covered within the scope of protection of the present application.

Claims

1. A self-generating, self-filtering, ozone catalytic water treatment device, characterized by, It includes a cavity, an ozone generation system, an aluminum-air battery system, an energy storage system, a self-filtering ozone catalyst material, and a water collection tank; the bottom of the cavity is equipped with an aeration system for ozone aeration; the aluminum-air battery system is submerged below the liquid surface in the cavity and located above the aeration system, wherein the cathode material of the aluminum-air battery is composed of a self-filtering ozone catalyst material, which also serves as an electrode and a water filtration channel. The self-filtering ozone catalyst material, along its thickness direction, has an inner layer that is hydrophilic with a contact angle ranging from 0° to 40°; and an outer layer that is hydrophobic with a contact angle ranging from 150° to... The inner layer serves as a water flow channel, and the outer layer serves as a gas diffusion layer, promoting mass transfer and in-situ catalysis of ozone gas on the porous material surface. The self-filtering ozone catalytic material includes a porous carbon matrix and an ozone heterogeneous catalytic layer. The porous carbon matrix is ​​a porous conductive carbon material. A Y-shaped support layer is set at the top of the cavity wall. The self-filtering ozone catalytic material is suspended in an inverted U-shape on the Y-shaped support layer. With the liquid surface and the Y-shaped support layer as the dividing point, the self-filtering ozone catalytic material is divided into three parts along its length: front, middle, and rear. The front part is submerged below the water surface with the aluminum-air battery, the middle part is higher than and perpendicular to the water surface, and the rear part is suspended above the water collection tank. The aluminum-air battery system is a sandwich structure battery module with a dual anode and a single cathode. The middle part is the self-filtering ozone catalytic material, and the two sides of the self-filtering ozone catalytic material are sequentially arranged with a separator, an aluminum anode, and a plastic clamp. The self-filtering ozone catalytic material serves as the cathode, and the cathode and aluminum anode are connected by wires and an energy storage system to collect the generated electrical energy. The area of ​​the separating material is the same as the apparent area of ​​the aluminum anode, and the apparent area of ​​the self-filtering ozone catalytic material is 2-10 times that of the aluminum anode.

2. The self-generating self-filtering ozone catalytic water treatment device according to claim 1, characterized in that, The porous carbon matrix is ​​graphite felt, activated carbon felt, carbon cloth, or carbon aerogel.

3. The self-generating self-filtering ozone catalytic water treatment device according to claim 2, characterized in that, The porous carbon matrix has a thickness of 0.2cm-5cm and an average pore size of 0.5μm-5μm.

4. The self-generating, self-filtering ozone catalytic water treatment device according to claim 1, characterized in that, The catalyst layer is one or more composites of graphene oxide, conductive carbon black oxide, carbon nanotube oxide, or carbon powder material doped with N or S elements.

5. A wastewater treatment method based on the self-generating, self-filtering ozone catalytic water treatment device as described in any one of claims 1-4, comprising: (1) Ozone promotes efficient power generation of aluminum batteries and wastewater pretreatment: High-efficiency power generation: When wastewater enters the chamber, ozone gas is generated by the ozone generation system and introduced into the chamber through the ozone aeration system at the bottom of the chamber. The ozone concentration ranges from 60 mg / L to 120 mg / L. In the aluminum-air battery system immersed in the wastewater, the self-filtering ozone catalyst material serves as the cathode, aluminum material serves as the anode, and inorganic salts in the wastewater serve as the electrolyte to undergo an electrochemical reaction. Under the dual action of ozone and oxygen gas, the cathode potential is increased, accelerating the corrosion and power generation of the aluminum anode. The generated electrical energy is collected by the energy storage system through the circuit. High-efficiency wastewater pretreatment: The aluminum corrosion products generated act as excellent homogeneous ozone catalysts, accelerating the decomposition of ozone and generating a large amount of active oxygen substances, promoting the rapid degradation of recalcitrant substances in wastewater; on the other hand, the aluminum corrosion products act as flocculants and precipitants, promoting the flocculation of macromolecular substances in wastewater, the precipitation of phosphate and fluoride ions, and the adsorption of heavy metal ions, achieving a highly efficient synergistic effect of the multifunctional water purification function of aluminum corrosion products. (2) Wastewater self-filtration, ozone in-situ catalysis and advanced wastewater treatment: Solid-liquid autonomous separation and self-filtration: The large amount of Al flocculants and precipitates generated during the pretreatment process settle naturally at the bottom of the chamber under gravity. Small particulate pollutants in the wastewater are simultaneously filtered by the internal pores of the self-filtering cathode material, thus achieving further purification. On the other hand, dissolved salts and water molecules in the wastewater further rise perpendicular to the water surface along the length of the self-filter under the capillary action of the cathode material. After passing through the Y-shaped support layer, they flow into the rear of the self-filtering material. Through the above-mentioned active mass transfer and transport process of water molecules, the wastewater can flow autonomously without any external energy input. Under gas aeration conditions, the dirt adhering to the surface of the self-filtering cathode can be cleaned in situ during ozone gas aeration, realizing the autonomous cleaning function of the surface of the self-filtering ozone catalyst material. In-situ heterogeneous catalysis of ozone: During the migration and mass transfer of pretreated wastewater in the inner layer of the self-filtering ozone catalytic material, gaseous ozone diffuses from the surface of the material to the inner layer. Under the action of the heterogeneous ozone catalyst in the inner layer, a large amount of surface-adsorbed ROS is generated on the surface of the material, which reacts with the wastewater flowing in the inner layer to carry out catalytic oxidation reaction, promoting the oxidation and degradation of recalcitrant and soluble organic pollutants in the wastewater. In-situ electrochemical catalysis of ozone: During the power generation process of aluminum-air batteries, the self-filtering ozone catalytic material, acting as the cathode, generates a certain external potential. In addition to the heterogeneous catalysis mentioned above, the external potential further accelerates the reduction reaction of ozone and oxygen on the surface of the material, producing ozone free radicals and H2O2, which further promotes more ROS in ozone catalytic products, accelerates the rapid removal of recalcitrant organic matter in wastewater, and ultimately achieves efficient synergy between the heterogeneous catalysis and electrochemical catalysis of ozone using the self-filtering ozone catalytic material. The self-filtering material enhances the reaction by plugging the flow: During the ozone catalysis process of the self-filtering material, the concentration of pollutants in the wastewater gradually decreases along the length of the self-filtering material. The self-filtering ozone catalytic material is regarded as a plugging-flow, porous electrochemical micro-reaction system along its length. Along the length, the wastewater will only flow in one direction under the action of capillary action and gravity, and eventually flow into the collection tank.

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