Water Treatment Apparatus Having an Electrocoagulation-Based Particle Growth Capture Structure and an Electrolysis-Based Sterilization Structure

Abstract

The present invention relates to water treatment technology, and more specifically, to a water treatment device that prevents the re-diffusion of fine particles into the water tank by adsorbing and growing them onto metal hydroxide flocs generated by electro-coagulation and then capturing them inside a filter section composed of porous partitions, and simultaneously sterilizes and inactivates microbial contaminants in the treated water and oxidizes and decomposes dissolved organic carbon using hypochlorous acid generated by electrolysis.

Description

Technology Field

[0001] The present invention relates to water treatment technology, and more specifically, to a water treatment device that prevents the re-diffusion of fine particles into the water tank by adsorbing and growing them onto metal hydroxide flocs generated by electro-coagulation and then capturing them inside a filter section composed of porous partitions, and simultaneously sterilizes and inactivates microbial contaminants in the treated water and oxidizes and decomposes dissolved organic carbon using hypochlorous acid generated by electrolysis. Background Technology

[0002] The content described in this section merely provides background information regarding the present invention and does not constitute prior art.

[0003] Recently, as modern people's leisure activities have diversified, interest in hobbies utilizing aquariums—such as raising ornamental fish, decorating planted tanks, and keeping saltwater fish—has been rapidly increasing, going beyond simple pet ownership.

[0004] In particular, as the culture of creating underwater landscapes, known as aquascaping, spreads through YouTube and social media, the penetration rate of home aquariums is on the rise every year.

[0005] Accordingly, maintaining clean and transparent water quality within the tank is recognized as a key management factor directly linked not only to securing aesthetic appeal for ornamental purposes but also to the health and survival of the aquatic life.

[0006] Generally, large and small foreign substances are continuously generated in aquariums due to various causes, such as animal waste, leftover feed, fallen aquatic plants, and dead microorganisms.

[0007] If these foreign substances accumulate in the tank, water quality deteriorates and can cause stress to the aquatic life; therefore, the use of a filtration system to remove them is essential for tank management.

[0008] Conventionally, various physical filtration devices such as plastic mesh filters, cotton filters, sponge filters, and ceramic ring filters have been widely used to remove such foreign substances.

[0009] These conventional filters generally operate by capturing and removing relatively large particles of several hundred micrometers or larger, and are highly effective at filtering out foreign substances of a size identifiable to the naked eye.

[0010] For example, lumps of fish excrement, pieces of leftover food, and leaves fallen from aquatic plants can be removed relatively easily through such conventional filters.

[0011] However, one of the common problems experienced by users managing water tanks is that, despite using these conventional filters, the water in the tank frequently becomes cloudy or fails to maintain clear transparency.

[0012] It is known that such cloudiness or a decrease in transparency is caused not by large particles that can be removed by conventional filters, but by fine particles that are extremely difficult to observe with the naked eye.

[0013] Specifically, the types and sizes of fine particles that reduce transparency in the water tank are as follows.

[0014] First, there is bacterial bloom. This is a phenomenon in which nitrifying bacteria and heterotrophic bacteria in the tank multiply rapidly and float in the water; the individual size of these bacteria ranges from approximately 0.2 micrometers to 5 micrometers. It occurs frequently, particularly during the initial tank setup phase or when excessive food is fed, and is one of the main causes of the water turning milky white.

[0015] Second, there are phytoplankton and microalgae. If the lighting directed at the tank is excessive or the concentration of nutrients in the water is high, microalgae proliferate rapidly, causing the so-called green algae bloom where the water in the tank turns green.

[0016] The individual size of these microalgae is approximately 2 to 30 micrometers, making it difficult to effectively capture them with conventional cotton filters or sponge filters.

[0017] Third, there are colloidal organic substances. These are proteins, lipids, humic acids, etc., generated during the metabolic processes of organisms in the tank and dispersed in the water in an ultrafine colloidal state, with a size of only about 0.001 micrometers to 1 micrometer. Because the particle size of these colloidal organic substances is extremely fine, they are virtually impossible to remove with conventional physical filters and impart a yellowish or yellowish-brown tint to the water in the tank, thereby reducing transparency.

[0018] Fourth, there are fine sediments and silt particles. These are fine dust particles that are separated from bottom materials, such as substrate soil or sand, placed on the bottom of the tank and suspended in the water; their size ranges from approximately 2 micrometers to 50 micrometers. These fine sediments are generated in large quantities during the initial installation of the tank or when the bottom material is stirred, and since natural settling takes a considerable amount of time, they become a factor that impairs the transparency of the tank for a long time.

[0019] Fifth, there are aggregated microparticles of dissolved organic carbon. Organic substances dissolved in water aggregate with each other due to changes in water quality conditions and float in the water in the form of fine particles, with a size of approximately 1 micrometer to 10 micrometers.

[0020] As mentioned above, the fine particles that reduce transparency in water tanks vary greatly in size, generally ranging from tens of micrometers or less to the sub-micrometer level, and it is structurally impossible or extremely difficult to capture and remove these fine particles with the pore sizes of conventional physical filtration devices.

[0021] Meanwhile, there are technologies available to remove such fine particles. For example, microfiltration methods using a microfiltration membrane, microbial killing methods using a UV sterilizer, microfiltration methods using a diatomaceous earth filter, or chemical filtration methods that remove fine particles after coagulating them by administering a coagulant are known.

[0022] However, these methods have the problem that not only is the purchase cost of the equipment itself high, but the short filter replacement cycle also results in excessive maintenance and management costs.

[0023] In addition, while UV sterilizers can kill microorganisms, there is a limitation in that the dead bodies of the microorganisms themselves remain in the water, making it difficult to expect a physical particle removal effect.

[0024] Furthermore, most of the aforementioned high-cost filtration systems are designed primarily for industrial facilities, such as large aquariums or fish farms, and face significant practical limitations in terms of equipment size, power consumption, noise, and installation space when applied to small-scale tanks in ordinary households.

[0025] As a result, general household aquarium users are unable to fundamentally resolve the problem of water turbidity caused by fine particles and are forced to rely on frequent water changes or tolerate turbid water quality.

[0026] Therefore, there is an urgent need to develop new filtration technology that can effectively capture and remove fine particles from water at low cost without the need for separate expensive equipment, even in general household aquarium environments, thereby stably maintaining the transparency of the aquarium for a long period. The problem to be solved

[0028] The problem to be solved by the present invention is to compensate for the disadvantages of the aforementioned prior art, and the objective of the present invention is as follows.

[0029] First, the present invention aims to provide a water treatment device capable of effectively removing fine particles ranging in size from sub-micrometers to tens of micrometers, which are difficult to capture with conventional physical filtration devices.

[0030] Second, the present invention aims to provide a water treatment device capable of inactivating microbial contaminants, which are difficult to completely remove by physical capture by electrocoagulation alone, through oxidative sterilization.

[0031] Third, the present invention aims to provide a water treatment device capable of effectively removing dissolved organic carbon, which is one of the main causes of reduced water transparency in a water tank, through a dual mechanism of capture and decomposition.

[0032] Fourth, the present invention aims to provide a water treatment device capable of customized water treatment optimized for the water quality environment of a water tank by having the electrocoagulation unit and the electrolysis unit each perform different removal mechanisms targeting different pollutants, and controlling the operating conditions of both independently or in conjunction according to the water quality state of the treated water.

[0033] The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0034] A water treatment device according to one embodiment of the present invention comprises: a tank portion in which fish and aquatic organisms are reared and treated water to be treated is received; a filter portion formed by a porous partition wall having a predetermined pore, disposed inside the tank portion or at a location fluidly communicating with the tank portion; an electrocoagulation portion disposed inside the filter portion and generating metal hydroxide flocs by electrochemical leaching of a sacrificial electrode; and an electrolysis portion disposed to contact the treated water and generating hypochlorous acid by electrolysis.

[0035] The filter unit is configured to allow fine particles contained in the treated water to flow into the interior through the pores, while blocking particles that have grown to a size larger than a predetermined size from flowing out to the outside.

[0036] The metal hydroxide floc generated in the electrocoagulation unit adsorbs the fine particles introduced into the filter unit and grows to a size larger than the pore size, thereby preventing the fine particles from re-diffusing into the water tank unit and trapping them inside the filter unit.

[0037] The electrocoagulation unit physically captures and removes particulate pollutants, including fine particles, colloidal organic matter, suspended solids, and phosphates in the treated water, by adsorbing them onto flocs, and the electrolysis unit sterilizes and inactivates microbial pollutants, including bacteria, viruses, fungi, and algae in the treated water, by the oxidizing power of the hypochlorous acid, and oxidizes and decomposes dissolved organic carbon in the treated water by the oxidizing power of the hypochlorous acid.

[0038] The above electrolysis unit is positioned outside the filter unit, so that floc generation by the electro-coagulation unit and hypochlorous acid generation by the electrolysis unit can be performed spatially independently and separately.

[0039] The electrolysis unit may include at least one pair of electrolytic electrodes that generate hypochlorous acid by electrolyzing chloride ions dissolved in the treated water, and at least one electrode among the pair of electrolytic electrodes may be composed of an insoluble electrode comprising at least one of titanium, platinum, iridium oxide, and ruthenium oxide. The anode of the pair of electrolytic electrodes may be composed of a dimensionally stable anode electrode having iridium oxide or ruthenium oxide coated on the surface of a titanium substrate.

[0040] The electrolysis unit is positioned on a circulation path that fluidly communicates with the water tank unit and the filter unit, so that the treated water can pass through the electrolysis unit to generate hypochlorous acid, after which it can be recirculated to the filter unit or the water tank unit.

[0041] The above water treatment device may further include a power supply unit that supplies power to the electrocoagulation unit and the electrolysis unit, and the power supply unit can independently control the current density, operating time, and operating mode of each of the electrocoagulation unit and the electrolysis unit.

[0042] The power supply unit may include an alternating operation mode for driving the electrocoagulant and the electrolysis unit alternately over time. In the alternating operation mode, the electrocoagulant may be driven for a predetermined first time period, followed by driving the electrolysis unit for a subsequent predetermined second time period. A predetermined rest period may be interposed between the driving of the electrocoagulant and the driving of the electrolysis unit.

[0043] In addition, the power supply unit may further include a simultaneous operation mode that drives the electro-coagulation unit and the electrolysis unit simultaneously, and the driving ratio of the electro-coagulation unit and the driving ratio of the electrolysis unit can be variably adjusted according to the water quality condition of the treated water.

[0044] The water treatment device may further include at least one of a turbidity sensor for measuring the turbidity of the treated water and a residual chlorine sensor for measuring the residual chlorine concentration of the treated water, and the power supply unit may feedback control the operation of the electrocoagulation unit and the electrolysis unit based on the measurement value of the sensor.

[0045] The above electrolysis unit is linked to the polarity switching cycle of the above electrocoagulation unit, so that the operation of the above electrolysis unit may be temporarily suspended or the current density may be reduced while the polarity switching of the above electrocoagulation unit is performed.

[0046] Additional means of solution of the present invention will be partially described in the following description, which may be partially easily identified from the description or obtained through the practice of the present invention.

[0047] The foregoing general description and the following detailed description are merely illustrative and illustrative and do not limit the invention as described in the claims. Effects of the invention

[0049] The effects of the present invention configured as described above are as follows.

[0050] First, since the metal hydroxide floc generated by the electrochemical elution of the sacrificial electrode adsorbs fine particles through multiple mechanisms such as electrostatic adsorption, ligand exchange, co-precipitation, physical capture, and bridge bonding, it is possible to effectively capture and remove various types of fine particles, such as bacteria, microalgae, colloidal organic matter, dissolved organic carbon, phosphates, silicates, algal spores, biofilm fragments, metal ions, and fine suspended solids, which were difficult to remove by conventional physical filtration methods.

[0051] Second, by adopting a structure in which an electrocoagulant is placed inside a filter section formed by a porous partition, it is possible to physically block fine particles that have been adsorbed to the flocs and grown beyond the size of the pores from flowing out of the filter section.

[0052] Third, since the oxidizing power of hypochlorous acid generated in the electrolysis unit can sterilize and inactivate microbial contaminants such as bacteria, viruses, fungi, and algae remaining in the treated water, it can complement the water treatment effect for microbial contaminants that are difficult to completely remove by physical capture alone in the electrocoagulation unit.

[0053] Fourth, since a dual removal mechanism of co-precipitation by the electro-coagulation unit and oxidative decomposition by the electrolysis unit acts on dissolved organic carbon, it is possible to improve the removal efficiency of dissolved organic carbon, which is difficult to achieve with a single mechanism alone.

[0054] Fifth, since the operating conditions of the electrocoagulation and electrolysis units can be controlled independently or in conjunction according to the water quality of the treated water, selective and variable responses to pollution types are possible, and water treatment efficiency and biological safety can be simultaneously ensured through the automatic suppression of residual chlorine concentration.

[0055] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0057] FIG. 1 is a perspective view of a water treatment device according to one embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating the filtration principle of a water treatment device according to one embodiment of the present invention. FIG. 3 is a drawing of a water tank in which a water treatment device according to one embodiment of the present invention is directly applied. Specific details for implementing the invention

[0058] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the attached drawings.

[0059] The aforementioned objects, features, and advantages of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. However, as the present invention is subject to various modifications and may include various embodiments, specific embodiments are illustrated in the drawings and described in detail below.

[0060] If it is determined that a detailed description of known functions or configurations related to the present invention could unnecessarily obscure the essence of the invention, such detailed description is omitted. Furthermore, numbers used in the description of this specification are merely identification symbols to distinguish one component from another.

[0061] Furthermore, the suffix "bu" for components used in the following description is used merely to facilitate the drafting of the specification or for interchangeable purposes, and does not inherently possess a distinct meaning or role.

[0062] A water treatment device according to one embodiment of the present invention comprises: a tank portion in which fish and aquatic organisms are reared and treated water to be treated is received; a filter portion disposed inside the tank portion or at a location fluidly communicating with the tank portion and formed by a porous partition wall having a predetermined pore, which allows fine particles contained in the treated water to flow into the interior through the pores but blocks particles that have grown to a size larger than a predetermined size from flowing out to the exterior; and an electrocoagulation portion disposed inside the filter portion and generating metal hydroxide flocs by electrochemical leaching of a sacrificial electrode.

[0063] The metal hydroxide floc generated in the above electrocoagulation unit is characterized by adsorbing fine particles introduced into the filter unit and growing them to a size larger than the pore size, thereby preventing the fine particles from re-diffusing to the outside of the filter unit and trapping them inside the filter unit.

[0064] In other words, the present invention provides a water treatment device capable of effectively removing fine particles ranging in size from sub-micrometers to tens of micrometers, which could not be captured by conventional simple physical filtration methods, by simultaneously utilizing a dual capture mechanism consisting of physical blockage by a filter unit and chemical adsorption and coagulation by an electrocoagulation unit.

[0065] The water tank according to the present invention is a component in which fish and aquatic organisms are reared and treated water to be treated is received.

[0066] In the treated water contained in the aforementioned tank, foreign substances and fine particles of various sizes are continuously generated by fish excrement, residual feed, fallen leaves of aquatic plants, dead microorganisms, and fine dust released from the substrate; as these fine particles float in the water, a problem arises in which the transparency of the water quality deteriorates.

[0067] Meanwhile, the above-mentioned tank section may be equipped with auxiliary facilities for maintaining a rearing environment for fish and aquatic organisms, such as an aeration device, a heater, a lighting device, an external filter, and substrate.

[0068] The filter portion according to the present invention is disposed inside the water tank portion or at a location fluidly communicating with the water tank portion, and is formed of a porous partition wall having a predetermined pore.

[0069] When the filter unit is positioned inside the water tank, the filter unit operates by being directly immersed in the treated water within the water tank and coming into contact with the treated water. In this case, the filter unit can be installed in various ways, such as being fixed to the inner wall of the water tank with an adsorption mount, resting on the bottom surface of the water tank by its own weight, or mounted by hooking onto a frame at the top of the water tank.

[0070] Meanwhile, when the filter unit is positioned in a location fluidly connected to the water tank unit, the filter unit is installed separately outside the water tank unit, and operates in such a way that treated water from the water tank unit flows into the filter unit through piping or a flow path, and the treated water is recirculated back to the water tank unit.

[0071] For example, a separate housing may be provided outside the water tank section to accommodate the filter section inside the housing, and the treated water may be configured to circulate through an inlet pipe and an outlet pipe connecting the housing and the water tank section. This external placement method has the advantage of facilitating the maintenance of the filter section while maintaining the aesthetics of the interior of the water tank section.

[0072] The filter portion may be formed from at least one of a mesh, porous ceramic, porous metal, fiber filter, nonwoven fabric, and foam body.

[0073] Specifically, the mesh is formed by weaving materials such as stainless steel, nylon, or polyester, and has the advantage of having a uniform pore size.

[0074] Porous ceramics are formed by sintering ceramic materials such as alumina, zirconia, and cordierite, and have the advantages of excellent corrosion and heat resistance, as well as high stability against the chemical environment in a water bath.

[0075] Porous metals are manufactured by sintering metal powders such as stainless steel, titanium, and nickel, or by forming them into foamed metals; they possess excellent mechanical strength and are suitable for long-term use. Fiber filters are made by processing synthetic fibers such as polypropylene and polyester, or natural fibers, into a non-woven fabric form, while foam bodies are porous structures formed using foamed resins such as polyurethane or melamine.

[0076] In addition, the filter portion is not limited to being formed from a single material, but may be formed by stacking or combining multiple materials. For example, the outer side may be formed from a mesh material with excellent mechanical strength, and the inner side may be formed from a non-woven fabric material having fine pores to constitute a filter portion with a composite structure.

[0077] The size of the pores of the filter section is 10 micrometers to 500 micrometers, and preferably 50 micrometers or less.

[0078] If the pore size is less than 10 micrometers, the flow resistance of the treated water increases excessively, which may hinder the smooth inflow of the treated water into the filter section, and there is a risk that foreign substances will rapidly accumulate on the surface of the filter section, thereby shortening the service life of the filter section.

[0079] On the other hand, if the pore size exceeds 500 micrometers, flocs that have been aggregated and grown by the electro-coagulation unit may leak out through the pores, so the collection efficiency may be reduced.

[0080] However, the above range corresponds to a preferred embodiment and can be appropriately adjusted by a person skilled in the art by considering the capacity of the water tank, the degree of contamination of the treated water, the size of the flocs generated by the electro-coagulation unit, etc.

[0081] For example, if the flocs are grown sufficiently large by adjusting the electrocoagulation conditions, the capture effect can be maintained even if pores exceeding 500 micrometers are applied, and conversely, if the capture of ultrafine particles is particularly required, pores of less than 10 micrometers may be applied.

[0082] The overall shape of the filter part is not particularly limited and can be implemented in various shapes such as cylindrical, rectangular, spherical, hemispherical, conical, and polygonal prism.

[0083] In the case of a cylindrical shape, it is advantageous to arrange the electrodes of the electrocoagulation unit concentrically inside, while in the case of a rectangular shape, it is advantageous to place them in close contact with the inner wall of the water tank to increase space efficiency.

[0084] In addition, the filter section may be formed as a tubular structure with both ends open to allow the treated water to pass through in one direction, or it may be formed as an enclosure structure with all sides closed to allow the treated water to flow in and out only through the pores.

[0085] According to one embodiment of the present invention, the filter portion may be formed such that the diameter of the pores on the inner surface is larger than the diameter of the pores on the outer surface, so as to prevent fine particles introduced from the water tank portion into the interior of the filter portion from being discharged to the outside of the filter portion.

[0086] In this way, by adopting a gradient structure in which the pore diameter gradually decreases from the inner surface to the outer surface of the filter section, it is possible to physically block fine particles adsorbed and aggregated by electro-coagulation inside the filter section from passing through the walls of the filter section and escaping to the outside.

[0087] Specifically, since the pore diameter of the inner surface is relatively large, it allows fine particles contained in the treated water of the tank to flow into the filter section, while since the pore diameter of the outer surface is relatively small, it can effectively prevent aggregated particles or flocs from flowing out in the reverse direction.

[0088] Such a gradient of pore diameters may be formed continuously or in stages. In the case of a continuous gradient, the pore diameter changes gradually along the thickness direction of the filter section, which can be achieved, for example, by controlling the particle size distribution during the sintering process of porous ceramics.

[0089] In the case of a step gradient, it can be formed by stacking multiple porous layers having different pore diameters, for example, by placing a mesh layer with a pore diameter of 200 micrometers on the inside and a nonwoven fabric layer with a pore diameter of 50 micrometers on the outside.

[0090] The electrocoagulation unit according to the present invention is disposed inside the filter unit and is a component that generates metal hydroxide flocs by electrochemical leaching of a sacrificial electrode.

[0091] The above electrocoagulation unit includes at least one pair of electrodes, each consisting of an anode and a cathode spaced apart from each other within the filter unit.

[0092] At least one of the above anode and cathode is a sacrificial electrode comprising at least one of aluminum, iron, zinc, and magnesium.

[0093] Specifically, when aluminum is used as a sacrificial electrode, aluminum ions are electrochemically eluted from the anode and react with hydroxide ions in the treated water, thereby forming a floc in the form of an amorphous hydroxide gel containing aluminum hydroxide.

[0094] When iron is used as a sacrificial electrode, iron ions are leached from the anode, forming a floc in the form of an amorphous hydroxide gel containing iron hydroxide.

[0095] When zinc is used as a sacrificial electrode, zinc hydroxide floc is formed, and when magnesium is used as a sacrificial electrode, magnesium hydroxide floc may be formed.

[0096] In addition, the sacrificial electrode is not limited to being formed from a single metal, but may be formed by alloying multiple metals, such as an alloy of aluminum and iron or an alloy of aluminum and magnesium. When using an alloy electrode, multiple types of metal hydroxides are generated simultaneously, which can improve the adsorption efficiency for fine particles.

[0097] The above electrode pair can be formed in any one of the following shapes: flat plate, rod, mesh, and cylindrical.

[0098] In the case of planar electrodes, multiple electrode plates are arranged facing each other in parallel, so that adjacent electrodes alternately function as positive and negative electrodes. Due to this alternating arrangement structure, a uniform electric field is formed in each gap between adjacent electrodes, and flocs are efficiently generated in each gap.

[0099] Meanwhile, the shape and arrangement of the electrode pair are not limited to the above embodiments, and various shapes capable of increasing the surface area of ​​the electrodes may be applied, such as spirally wound coil-type electrodes, corrugated wavy electrodes, or pin-type electrodes with multiple protruding pins. Furthermore, the arrangement of the electrodes is not limited to parallel or concentric arrangements, and various arrangement methods suitable for the internal shape of the filter section may be applied, such as radial arrangement, grid arrangement, or asymmetric arrangement.

[0100] The metal hydroxide floc according to the present invention adsorbs the microparticles by the simultaneous action of at least two mechanisms among electrostatic adsorption, ligand exchange, co-precipitation, physical capture, and bridge bonding.

[0101] Electrostatic adsorption is a mechanism in which negatively charged microparticles, such as colloidal organic matter, bacteria, and microalgae, are attached to the surface of metal hydroxide flocs by electrostatic attraction under conditions where the surface of the metal hydroxide flocs is positively charged.

[0102] Ligand exchange is a mechanism by which microparticles are adsorbed onto the flocs by forming coordination bonds between the hydroxyl groups on the surface of the metal hydroxide flocs and anionic pollutants such as phosphates and silicates in the treated water.

[0103] Co-precipitation is a mechanism in which dissolved organic carbon, metal ions, etc. in the treated water are captured within the gel structure and precipitated together during the process in which metal hydroxide precipitates in the form of an amorphous gel.

[0104] Physical capture is a mechanism in which fine particles are physically trapped in the pore structure formed inside the metal hydroxide floc as it grows.

[0105] Bridge bonding is a mechanism in which high molecular weight metal hydroxide chains cross-link multiple microparticles, causing individually fine particles to bond together and grow into larger aggregates.

[0106] By having multiple such adsorption mechanisms operate simultaneously, the water treatment device according to the present invention can comprehensively adsorb and capture various types of microparticles with different charge characteristics or chemical compositions.

[0107] It is preferable that the above floc grow to a size of 100 micrometers to 500 micrometers by adsorption of fine particles. When the floc grows to a size within the above range, it exceeds the pore size of the filter section, so the floc and the fine particles adsorbed thereon are physically blocked from flowing out through the pores of the filter section, and accordingly, the re-diffusion of fine particles into the water tank section is prevented.

[0108] However, the growth size of the floc may vary depending on the electrocoagulation conditions, the water quality characteristics of the treated water, the concentration of fine particles, etc., and it is possible to grow it to a size exceeding 500 micrometers by increasing the current density or extending the coagulation time. In addition, even if the floc size is less than 100 micrometers, the capture effect can be maintained if the pore size of the filter part is set to be smaller than this.

[0109] The microparticles to be treated in the present invention include at least one of dissolved organic carbon, phosphate, silicate, colloidal organic matter, bacteria, microalgae, algae spores, biofilm fragments, metal ions, and fine suspended particles.

[0110] Specifically, dissolved organic carbon is a water-soluble organic substance derived from metabolic products of organisms in the tank, decomposition products of feed, etc., and causes a yellowish-brown tint to the water in the tank, thereby reducing transparency.

[0111] Phosphates and silicates are nutrients derived from animal feed, substrates, tap water, etc., and when present in excessive amounts in water, they induce abnormal proliferation of microalgae, thereby promoting algal blooms. Colloidal organic matter consists of proteins, humic acid, fulvic acid, etc., dispersed in a colloidal state in water; due to the extremely fine particle size, it is virtually impossible to remove them using conventional physical filters.

[0112] Bacteria, such as nitrifying bacteria and heterotrophic bacteria, rapidly multiply within the tank and float in the water, serving as the main cause of the so-called turbidity.

[0113] Microalgae and algae spores float in the water and cause it to turn green, while biofilm fragments are biofilms formed on the inner walls of aquariums or the surfaces of decorations that detach and float in the water.

[0114] Metal ions include heavy metal ions such as copper, zinc, and iron contained in tap water, or metal components leached from flooring materials. Fine suspended matter is a collective term for fine suspended particles of other organic and inorganic components not included in the above classification.

[0115] At least some of the above fine particles are smaller in size than the pores of the filter section, and after passing through the filter section and entering the interior, they are adsorbed onto the metal hydroxide floc and captured.

[0116] In other words, fine particles smaller than the pores of the filter naturally flow into the filter due to the flow of the treated water, and are adsorbed onto flocs generated by the electrocoagulation unit inside. As they grow larger than the pore size, they are captured within the filter without being re-emitted to the outside.

[0117] A water treatment device according to one embodiment of the present invention may further include a power supply unit that supplies power to the electro-coagulation unit.

[0118] The power supply unit controls at least one of the current density, operating time, and polarity switching of the positive and negative poles of the electro-coagulation unit.

[0119] Controlling the current density involves adjusting the magnitude of the current applied to the electrocoagulation unit. As the current density increases, the amount of metal ions leached from the sacrificial electrode increases, leading to an increase in floc formation, but the rate of electrode consumption also increases. Therefore, it is desirable to set an appropriate current density by considering the capacity of the water tank, the degree of contamination of the treated water, etc.

[0120] Control of the operating time involves adjusting the time for supplying power to the electro-coagulation unit, and a method of supplying power continuously or intermittently may be applied. For example, by applying an intermittent operation mode that operates for 10 minutes and then stops for 2 hours, sufficient floc generation can be maintained while suppressing electrode consumption, and in cases where the turbidity of the treated water is particularly high, a continuous operation mode may be applied to generate flocs intensively.

[0121] The above polarity switching is performed at predetermined intervals to suppress scale formation on the electrode surface and extend the electrode life.

[0122] In the electrocoagulation process, scale such as oxides, hydroxides, or carbonates may form on the surface of the electrode functioning as the anode, which can lead to a decrease in electrode surface conductivity and reduced floc generation efficiency.

[0123] To prevent this, the polarity of the anode and cathode is switched at a predetermined interval. This allows the electrode where scale has begun to form to be switched to the cathode to remove the scale through an electrochemical reduction reaction, while the opposite electrode functions as the anode to continue floc formation. Additionally, since the consumption of both electrodes is evenly distributed due to the polarity switching, the overall service life of the electrode is extended.

[0124] The cycle of the polarity switching mentioned above is not particularly limited, but, for example, it is preferable to switch the polarity in units of 10 to 60 minutes, and in environments where the hardness of the treated water is high and the scale formation rate is fast, it is advantageous to switch the polarity at a shorter cycle.

[0125] Meanwhile, the above power supply unit may further include a timer function, a current limiting function, a low voltage alarm function, etc., and may be configured as an integral part of the existing power system of the external filter for the water tank or as a separate independent module.

[0126] In addition, while the power supply unit generally supplies DC power, a method of supplying pulsed DC power can also be applied, and when pulsed power is used, bubble generation on the electrode surface is promoted, which can improve the effect of suppressing scale formation.

[0127] According to one embodiment of the present invention, the metal hydroxide floc settles to the lower part of the filter section by gravity, and the filter section includes a replacement section on which the settled metal hydroxide floc is loaded and which is separable from the water tank section. The replacement section can be selectively detached and replaced when saturated.

[0128] Specifically, the metal hydroxide flocs generated by the electrocoagulation unit gradually settle and accumulate at the bottom of the filter unit due to gravity while adsorbing fine particles.

[0129] As time passes, the amount of floc accumulated in the replacement unit increases, and when the capacity of the replacement unit reaches saturation, the user can separate the replacement unit from the filter unit or water tank unit to wash it or replace it with a new replacement unit.

[0130] The above replacement part may be configured in the form of a detachable tray, drawer, cartridge, or cap at the bottom of the filter part.

[0131] In the case of a tray type, it can be configured to be inserted and withdrawn in a sliding manner at the bottom of the filter section, and in the case of a cartridge type, it can be detachably mounted to the filter section by means of screw coupling, snap coupling, or magnetic coupling.

[0132] In addition, a separate shielding structure may be provided in the replacement section to prevent settled flocs from leaking out of the replacement section. For example, a fine mesh may be installed on the upper surface of the replacement section to prevent the loaded flocs from refloating, or an uneven structure may be formed on the inner surface of the replacement section to improve the adhesion of the settled flocs.

[0133] Meanwhile, to allow the user to visually check whether the replacement part is saturated, the replacement part may be formed of a transparent or translucent material, or a viewing window may be provided on one side of the replacement part.

[0134] Furthermore, it may additionally include a configuration that installs a sensor to detect changes in weight or water level of the replacement part, automatically detects the point of saturation of the replacement part, and generates an alarm to the user.

[0135] A water treatment device according to one embodiment of the present invention may further include a pump unit that forms a circulating flow so that the treated water passes through the interior of the filter unit. The pump unit forms a side stream flow path that guides a portion of the treated water in the water tank unit to the filter unit.

[0136] Specifically, the pump section operates in a side-stream manner, diverting only a portion of the treated water to the filter section rather than directing the entire treated water within the tank section to the filter section. Accordingly, sufficient treated water flow for the electrocoagulation reaction within the filter section can be secured while minimizing the impact on the overall water flow within the tank section.

[0137] The above pump unit may utilize various types of pumps, such as small submersible pumps, external inline pumps, and airlift pumps.

[0138] A small submersible pump is placed submerged within the tank section to directly transfer treated water to the filter section, while an external inline pump is installed along the piping path outside the tank section to transfer the treated water.

[0139] The airlift pump transports treated water by utilizing the upward force of bubbles generated in an aeration device. It has the advantages of a simple structure and low power consumption, as it can form a circulating flow of treated water without the need for a separate mechanical pump.

[0140] In addition, it is desirable to set the flow rate of the pump section appropriately according to the capacity of the water tank section, for example, by operating at an hourly flow rate corresponding to 2 to 5 times the total volume of the water tank section, so that the treated water in the water tank section can be circulated through the filter section within a few hours.

[0141] Furthermore, the pump unit can be controlled in conjunction with the electrocoagulation unit of the filter unit. For example, by controlling the pump unit in conjunction so that it starts operating when power is supplied to the electrocoagulation unit and stops operating when the power to the electrocoagulation unit is cut off, energy waste caused by unnecessary pump operation can be prevented.

[0142] The overall operating principle of the water treatment device according to the present invention is described below.

[0143] First, the treated water contained in the tank section contains various microparticles generated during the fish rearing process, and among these microparticles, those smaller than the pores of the filter section pass through the pores and enter the filter section through the natural flow of the treated water or forced flow by the pump section.

[0144] Fine particles introduced into the filter section are adsorbed by metal hydroxide flocs electrochemically generated at the sacrificial electrode of the electrocoagulation section.

[0145] At this time, multiple adsorption mechanisms such as electrostatic adsorption, ligand exchange, co-precipitation, physical capture, and bridge bonding act simultaneously to comprehensively capture various types of microparticles.

[0146] Fine particles adsorbed onto flocs gradually grow in size along with the flocs, eventually exceeding the pore size of the filter section; consequently, their leakage to the outside through the porous baffles of the filter section is physically blocked. In particular, when the pore diameter on the inner surface of the filter section is larger than the pore diameter on the outer surface, the fine particles and flocs are doubly blocked by the pores that gradually narrow as they move toward the outer surface, thereby further enhancing the capture efficiency.

[0147] Sufficiently grown flocs gradually settle and accumulate in the replacement section at the bottom of the filter unit due to their own weight, and when the replacement section becomes saturated, the user can continuously maintain the collection performance of the water treatment device by separating and cleaning the replacement section or replacing it with a new one.

[0148] Meanwhile, since the current density, operating time, and polarity switching are controlled by the power supply unit, optimal operating conditions are set according to the capacity and contamination level of the water tank, and scale formation on the electrode surface is suppressed, enabling stable operation for a long period.

[0149] The electrolysis unit according to the present invention is arranged to come into contact with the treated water and is a component that generates hypochlorous acid by electrolysis.

[0150] While the above electrocoagulation unit performs the function of physically capturing and removing particulate pollutants by generating metal hydroxide flocs through the electrochemical leaching of a sacrificial electrode, the above electrolysis unit performs the function of oxidatively sterilizing and inactivating microbial pollutants, including bacteria, viruses, fungi, and algae, and oxidizing and decomposing dissolved organic carbon in the treated water by generating hypochlorous acid through the electrolysis of chloride ions dissolved in the treated water.

[0151] In other words, the electrocoagulation unit and the electrolysis unit each have different removal targets and operating mechanisms; the electrocoagulation unit is specialized for the adsorption and capture of particulate pollutants such as fine particles, colloidal organic matter, suspended solids, and phosphates, while the electrolysis unit is specialized for the sterilization of microbial pollutants and the oxidative decomposition of dissolved organic carbon. By working complementarily, the two achieve a comprehensive water purification effect that is difficult to attain with a single mechanism alone.

[0152] In particular, for dissolved organic carbon, a dual removal mechanism involving co-precipitation by the electro-coagulation unit and oxidative decomposition by the electrolysis unit acts simultaneously.

[0153] Specifically, some of the dissolved organic carbon is co-precipitated and physically captured within the amorphous gel structure of the metal hydroxide floc generated in the electrocoagulation section, and at the same time, the organic molecular bonds of the remaining dissolved organic carbon are broken by the oxidizing power of the hypochlorous acid generated in the electrolysis section and decomposed into low-molecular-weight compounds or carbon dioxide.

[0154] Accordingly, high concentrations of dissolved organic carbon that are not completely removed by capture alone through co-precipitation can be additionally removed by oxidative decomposition, thereby more effectively preventing the imparting of a yellowish-brown tint and a decrease in transparency of the treated water.

[0155] The electrolysis unit comprises at least one pair of electrolytic electrodes that electrolyze chloride ions dissolved in the treated water to produce hypochlorous acid.

[0156] Chloride ions are oxidized on the anode surface of the above electrolytic electrode pair to generate chlorine gas, and the chlorine gas reacts with the treated water to produce hypochlorous acid and hydrochloric acid.

[0157] In this case, when the hydrogen ion concentration of the treated water is in the neutral to weakly acidic range, the proportion of hypochlorous acid is relatively higher than that of hypochlorite ions, and hypochlorous acid is known to have significantly superior bactericidal power compared to hypochlorite ions.

[0158] Since the treated water in a typical household water tank is maintained at a hydrogen ion concentration of 6.5 to 7.5, the proportion of hypochlorous acid among the chlorine chemical species generated in the electrolysis unit according to the present invention becomes dominant.

[0159] At least one electrode among the above electrolytic electrode pair is composed of an insoluble electrode comprising at least one of titanium, platinum, iridium oxide, and ruthenium oxide.

[0160] Here, an insoluble electrode refers to an electrode that, unlike a sacrificial electrode used in the electrocoagulation unit, is not electrochemically leached out during the electrolysis process.

[0161] The sacrificial electrode of the electrocoagulation section is intended to form flocs by intentionally leaching metal ions through anodic oxidation, whereas the insoluble electrode of the electrolysis section is intended to generate chlorine gas by oxidizing chloride ions in the treated water without the leaching of the electrode itself.

[0162] According to one embodiment of the present invention, the anode of the electrolytic electrode pair may be composed of a dimensionally stable anode electrode having iridium oxide or ruthenium oxide coated on the surface of a titanium substrate.

[0163] The dimensionally stable anode electrode has excellent dimensional stability during the electrolysis process, so the shape change of the electrode is extremely minimal, and the chlorine generation overpotential is low, allowing for higher chlorine generation efficiency at the same current density. It also has excellent corrosion resistance, so it has the advantage of being able to be used stably for a long time in various chemical environments in treated water.

[0164] Meanwhile, the cathode of the above-mentioned electrolytic electrode pair may be formed from a material such as stainless steel, titanium, or graphite. At the cathode, hydrogen ions in the treated water are reduced to generate hydrogen gas, and during this process, the hydrogen ion concentration near the surface of the cathode increases locally.

[0165] The above electrolytic electrode pair can be formed in any one of the following shapes: flat plate, mesh, and concentric cylinder.

[0166] In the case of the flat plate type, the positive and negative plates are arranged parallel to each other, forming a uniform electric field in the gap between the electrodes, while the mesh type has the advantage of improving chlorine gas generation efficiency by increasing the electrode surface area.

[0167] In the case of a concentric cylinder, the inner electrode and the outer electrode are arranged concentrically, allowing the treated water to efficiently come into contact with chlorine gas as it passes through the annular gap between the electrodes.

[0168] Preferably, the distance between the electrodes of the above electrolytic electrode pair is 1 millimeter to 10 millimeters. If the distance between the electrodes is less than 1 millimeter, the risk of short circuit between the electrodes increases and the flow resistance of the treated water may become excessive, and if it exceeds 10 millimeters, the electrical resistance between the electrodes increases and power efficiency may decrease.

[0169] According to one embodiment of the present invention, the electrolysis unit is positioned outside the filter unit, so that floc generation by the electro-coagulation unit and hypochlorous acid generation by the electrolysis unit are performed spatially independently and separately.

[0170] Placing the electrolysis unit outside the filter unit in this manner is intended to prevent the hypochlorous acid generated in the electrolysis unit from affecting the aggregation characteristics of the metal hydroxide flocs generated in the electro-coagulation unit.

[0171] Specifically, hypochlorous acid is a strong oxidizing agent that may oxidatively alter the gel structure of metal hydroxide flocs or oxidatively decompose organic matter adsorbed on the flocs, causing it to detach from the flocs.

[0172] Therefore, it is desirable to spatially separate the electrocoagulation unit and the electrolysis unit so that each electrochemical reaction can be performed independently without mutual interference.

[0173] However, the placement location of the electrolysis unit is not limited to the above embodiments, and it is also possible to place the electrolysis unit inside the filter unit together with the electro-coagulation unit or place it directly inside the water tank unit.

[0174] According to one embodiment of the present invention, the electrolysis unit is positioned on a circulation path that fluidly communicates with the water tank unit and the filter unit, so that as the treated water passes through the electrolysis unit, hypochlorous acid is generated and then recirculated to the filter unit or the water tank unit.

[0175] For example, the treated water drawn from the water tank by the pump section can be configured to first pass through the electrolysis section along the circulation path and then flow into the filter section.

[0176] In this case, hypochlorous acid generated in the electrolysis unit flows into the filter unit while dissolved in the treated water, allowing for sequential floc collection by the electrocoagulation unit and sterilization by hypochlorous acid to occur inside the filter unit.

[0177] Alternatively, the system may be configured so that the treated water first passes through the filter section for capture treatment by the electro-coagulation section, and then the treated water exiting the filter section passes through the electrolysis section for sterilization treatment with hypochlorous acid, and the sterilized treated water is recirculated to the water tank section.

[0178] Furthermore, by configuring the system so that a portion of the treated water passes through the electrolysis unit and the remainder bypasses it and flows directly into the filter unit, it is also possible to indirectly control the amount of hypochlorous acid generated through the flow path distribution ratio.

[0179] The power supply unit according to the present invention supplies power to the electrocoagulation unit and the electrolysis unit, and independently controls the current density, operating time, and operating mode of each.

[0180] Since the electrocoagulation unit and the electrolysis unit each have different electrode materials, different electrochemical reactions, and different optimal current densities, driving both under a single, identical power supply condition is not suitable for achieving their respective optimal performance.

[0181] Therefore, the power supply unit independently controls the operating conditions of the electrocoagulation unit and the electrolysis unit, thereby enabling each component to operate under optimal electrochemical conditions.

[0182] According to one embodiment of the present invention, the power supply unit includes a cross-operation mode in which the electrocoagulant unit and the electrolysis unit are driven alternately in time.

[0183] In the above cross-operation mode, the electro-coagulation unit is driven for a predetermined first time to generate metal hydroxide flocs, and then the electrolysis unit is driven for a subsequent predetermined second time to generate hypochlorous acid.

[0184] For example, the first time can be set to 15 minutes and the second time to 10 minutes, and the electrocoagulation unit can be operated for 15 minutes to generate a sufficient amount of floc and to adsorb and capture fine particles, and then the electrolysis unit can be operated for 10 minutes to sterilize residual microorganisms in the treated water and oxidatively decompose dissolved organic carbon.

[0185] This cross-operation mode has the advantage of dispersing the concentration of power consumption that may occur when the electrocoagulation unit and the electrolysis unit are operated simultaneously, and maximizing the efficiency of each electrochemical reaction by temporally separating the effect of hypochlorous acid on floc formation in the electrocoagulation unit.

[0186] According to one embodiment of the present invention, a predetermined rest time may be interposed between the operation of the electrocoagulation unit and the operation of the electrolysis unit in the cross-operation mode.

[0187] The above rest time is intended to secure sufficient reaction time for the flocs generated by the electrocoagulation unit to adsorb and grow fine particles. Since floc generation is complete immediately after the operation of the electrocoagulation unit ends, but the adsorption of fine particles and floc growth may still be in progress, the collection efficiency by flocs can be improved by operating the electrolysis unit after a predetermined rest time has been provided and the flocs have grown sufficiently.

[0188] The above resting time is not specifically limited, but can be set to, for example, 5 to 30 minutes, and it is preferable to apply a shorter resting time when the adsorption reaction proceeds rapidly due to a high concentration of fine particles in the treated water, and a longer resting time when the concentration of fine particles is low.

[0189] According to one embodiment of the present invention, the power supply unit may further include a simultaneous operation mode that simultaneously drives the electrocoagulation unit and the electrolysis unit.

[0190] In the above simultaneous operation mode, the current density applied to the electrocoagulation unit and the current density applied to the electrolysis unit are each set independently. For example, a current density of 5 to 20 milliamperes per square centimeter can be independently applied to the electrocoagulation unit, and a current density of 10 to 50 milliamperes per square centimeter can be independently applied to the electrolysis unit. The simultaneous operation mode can be applied when the degree of contamination of the treated water is severe and it is necessary to simultaneously perform the capture of particulate contaminants and the sterilization of microorganisms.

[0191] In addition, the power supply unit can variably adjust the driving ratio of the electrocoagulation unit and the driving ratio of the electrolysis unit according to the water quality status of the treated water. Specifically, if the turbidity of the treated water exceeds a standard value, it is determined that the concentration of particulate pollutants is high, and thus the driving ratio of the electrocoagulation unit is relatively increased; and if the number of bacteria or the concentration of dissolved organic carbon exceeds a standard value, it is determined that microbial contamination or organic contamination is severe, and thus the driving ratio of the electrolysis unit is relatively increased.

[0192] Here, the driving ratio refers to at least one of the relative ratio of current density or the relative ratio of driving time within a unit time.

[0193] According to one embodiment of the present invention, the water treatment device may further include at least one of a turbidity sensor for measuring the turbidity of the treated water and a residual chlorine sensor for measuring the residual chlorine concentration of the treated water.

[0194] The above power supply unit feedback controls the operation of the electrocoagulation unit and the electrolysis unit based on the measurement value of at least one of the turbidity sensor and the residual chlorine sensor.

[0195] Specifically, if the measured value of the turbidity sensor is greater than or equal to the first reference value, it is determined that the concentration of fine particles in the treated water is high, and the current density of the electrocoagulation unit is increased or the operating time is extended; and if the measured value of the residual chlorine sensor is less than the second reference value, it is determined that the sterilization power is insufficient, and the current density of the electrolysis unit is increased or the operating time is extended.

[0196] Meanwhile, if the measured value of the residual chlorine sensor exceeds the third threshold value, it is determined that the residual chlorine concentration in the treated water has reached a level capable of causing toxicity to fish and aquatic organisms in the tank, and the current density of the electrolysis unit is reduced or operation is stopped. Accordingly, damage to aquatic organisms caused by excess chlorine can be prevented while maintaining water treatment efficiency.

[0197] The above first, second, and third reference values ​​may be set by the user considering the capacity of the tank, the type and sensitivity of the organism being raised, etc., or default values ​​pre-stored in the power supply unit may be applied.

[0198] According to one embodiment of the present invention, the water treatment device may further include at least one of a dissolved organic carbon sensor for measuring the dissolved organic carbon concentration of the treated water or a redox potential sensor for measuring the redox potential of the treated water.

[0199] The above power supply unit monitors the oxidative decomposition efficiency of dissolved organic carbon in the electrolysis unit based on the measurement value of the dissolved organic carbon sensor or the redox potential sensor, and adjusts the driving intensity of the electrolysis unit.

[0200] Specifically, if the measured value of the dissolved organic carbon sensor is high, it is determined that the concentration of dissolved organic carbon is high and there is a great need for oxidative decomposition, so the driving intensity of the electrolysis unit is increased; if the measured value of the dissolved organic carbon sensor decreases to within the standard range, the driving intensity of the electrolysis unit is lowered or operation is stopped. When using an oxidation-reduction potential sensor, since a higher oxidation-reduction potential indicates a higher oxidizing power of the treated water, the driving intensity of the electrolysis unit can be adjusted based on whether the oxidation-reduction potential value has reached the target range.

[0201] In addition, the power supply unit may include at least two operating modes among a normal mode, an intensive aggregation mode, and an intensive sterilization mode.

[0202] In normal mode, the driving intensity of the electrocoagulation unit is set to the first intensity and the driving intensity of the electrolysis unit is set to the second intensity, respectively, so that standard operation for daily water quality maintenance is performed.

[0203] In the intensive coagulation mode, the driving intensity of the electro-coagulation unit is increased to a third intensity, which is higher than the first intensity. This mode may be applied in cases where turbidity rises rapidly due to substrate dust during the initial tank setup phase, or when the concentration of fine particles temporarily increases due to excessive feed administration.

[0204] In intensive sterilization mode, the driving intensity of the electrolysis unit is increased to a fourth intensity, which is higher than the second intensity. This mode can be applied in cases where turbidity occurs due to bacterial bloom, or where an algal bloom occurs due to the rapid proliferation of microalgae.

[0205] Switching between the above operating modes can be performed by manual input from the user or automatically based on the measurements of the turbidity sensor, residual chlorine sensor, dissolved organic carbon sensor, or redox potential sensor described above.

[0206] According to one embodiment of the present invention, the electrolysis unit can be controlled in conjunction with the polarity switching cycle of the electro-coagulation unit.

[0207] At the moment the polarity of the electrocoagulation unit is switched, the positive and negative electrodes are reversed, which may cause temporary current fluctuations and transient phenomena. If the electrocoagulation unit and the electrolysis unit receive power from the same power supply, these transient phenomena may affect the current applied to the electrolytic electrode pair of the electrolysis unit, causing the amount of hypochlorous acid produced to become temporarily unstable.

[0208] To prevent this, the operation of the electrolysis unit is temporarily suspended or the current density is reduced while the polarity of the electrocoagulation unit is being switched. For example, by temporarily cutting off the current supply to the electrolysis unit or reducing the current density to less than half of that during normal operation in intervals of 2 to 10 seconds before and after the polarity switching point, the effect of the transient phenomenon caused by the polarity switching on the generation of hypochlorous acid can be minimized.

[0209] Meanwhile, it is confirmed that in an environment where the water quality in a tank to which the water treatment device according to the present invention is applied is properly managed, lesions such as depressions and tissue loss occurring on the body surface of fish recover naturally without the administration of drugs.

[0210] Specifically, in a state where water quality management is not performed, multiple depressions form on the body surface of fish and their body color darkens, indicating a state of stress and disease; however, in an environment where water quality is maintained stably, the depressions gradually decrease and the original body color is restored, and ultimately, the depressions completely disappear, restoring normal skin condition and natural color.

[0211] This means that as microbial contaminants and factors causing water quality deterioration within the tanks have been effectively removed, a healthy rearing environment has been established where fish are not susceptible to disease.

[0212] This embodiment is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations of this embodiment within the scope of the essential characteristics of the present invention.

[0213] This embodiment is intended to explain, not limit, the technical concept of the present invention, and therefore, the scope of the rights of the present invention is not limited by this embodiment.

[0214] The scope of protection of the present invention shall be interpreted by the claims, and all technical ideas recognized as equivalent or equivalent thereto shall be interpreted as being included in the scope of rights of the present invention. Explanation of the symbols

[0215] 10 - Water tank section 20 - Filter section 21 - Replacement part 30 - Electrocoagulation part 40 - Electrolysis section P - fine particles F-floc

Claims

Claim 1 A tank section in which fish and aquatic organisms are reared and treated water to be treated is received; a filter section disposed within the tank section or at a location fluidly connected to the tank section, formed by a porous partition having a predetermined pore, allowing fine particles contained in the treated water to flow into the interior through the pore, while blocking particles that have grown to a size larger than a predetermined size from flowing out to the exterior; and an electrocoagulation section disposed within the filter section, which generates metal hydroxide flocs by electrochemical leaching of a sacrificial electrode. A water treatment device comprising: an electrolysis unit positioned to contact the above-mentioned treated water and generating hypochlorous acid (HOCl) by electrolysis; wherein the metal hydroxide floc generated in the electrocoagulation unit adsorbs fine particles introduced into the filter unit and grows to a size greater than that of the pores, thereby preventing the fine particles from re-diffusing to the outside of the filter unit and capturing them within the filter unit; wherein the electrocoagulation unit physically captures and removes particulate pollutants including fine particles, colloidal organic matter, suspended matter, and phosphates in the above-mentioned treated water by adsorbing them onto the floc; wherein the electrolysis unit sterilizes and inactivates microbial pollutants including bacteria, viruses, fungi, and algae in the above-mentioned treated water by the oxidizing power of the hypochlorous acid, and oxidizes and decomposes dissolved organic carbon in the above-mentioned treated water by the oxidizing power of the hypochlorous acid; and wherein the electrolysis unit is positioned outside the filter unit, so that floc generation by the electrocoagulation unit and hypochlorous acid generation by the electrolysis unit are performed spatially independently and separately. Claim 2 delete Claim 3 A water treatment device according to claim 1, wherein the electrolysis unit comprises at least one pair of electrolytic electrodes that electrolyze chloride ions dissolved in the treated water to produce hypochlorous acid, and at least one electrode among the pair of electrolytic electrodes is composed of an insoluble electrode comprising at least one of titanium, platinum, iridium oxide, and ruthenium oxide. Claim 4 A water treatment device according to claim 3, wherein the anode of the electrolytic electrode pair is composed of a DSA (Dimensionally Stable Anode) electrode having an iridium oxide or ruthenium oxide coated on the surface of a titanium substrate. Claim 5 A water treatment device according to claim 1, wherein the electrolysis unit is disposed on a circulation path that fluidly communicates with the water tank unit and the filter unit, and the treated water passes through the electrolysis unit to generate hypochlorous acid, after which it is recirculated to the filter unit or the water tank unit. Claim 6 A water treatment device according to claim 1, further comprising a power supply unit that supplies power to the electrocoagulation unit and the electrolysis unit, wherein the power supply unit independently controls the current density, operating time, and operating mode of each of the electrocoagulation unit and the electrolysis unit, and wherein the power supply unit includes a cross-operation mode that alternately drives the electrocoagulation unit and the electrolysis unit in time, wherein in the cross-operation mode, the electrocoagulation unit is driven for a predetermined first time period to generate flocs, and then the electrolysis unit is driven for a subsequent predetermined second time period to generate hypochlorous acid. Claim 7 A water treatment device according to claim 6, characterized in that, in the above-mentioned cross-operation mode, a predetermined rest time is interposed between the operation of the electrocoagulation unit and the operation of the electrolysis unit, thereby securing a reaction time for the floc generated by the electrocoagulation unit to adsorb and grow fine particles, after which the electrolysis unit is operated. Claim 8 A water treatment device according to claim 6, wherein the power supply unit further includes a simultaneous operation mode for driving the electrocoagulation unit and the electrolysis unit simultaneously, wherein in the simultaneous operation mode, the current density applied to the electrocoagulation unit and the current density applied to the electrolysis unit are each independently set, and the power supply unit variably adjusts the driving ratio of the electrocoagulation unit and the driving ratio of the electrolysis unit according to the water quality state of the treated water, wherein the driving ratio of the electrocoagulation unit is relatively increased when the turbidity is above a reference value, and the driving ratio of the electrolysis unit is relatively increased when the number of bacteria or the dissolved organic carbon concentration is above a reference value. Claim 9 A water treatment device according to claim 8, further comprising at least one of a turbidity sensor for measuring the turbidity of the treated water and a residual chlorine sensor for measuring the residual chlorine concentration of the treated water, wherein the power supply unit feedback-controls the operation of the electrocoagulation unit and the electrolysis unit based on the measurement value of at least one of the turbidity sensor and the residual chlorine sensor, and wherein the power supply unit increases the current density of the electrocoagulation unit or extends the operating time when the measurement value of the turbidity sensor is greater than or equal to a first reference value, increases the current density of the electrolysis unit or extends the operating time when the measurement value of the residual chlorine sensor is less than a second reference value, and decreases the current density of the electrolysis unit or stops the operation when the measurement value of the residual chlorine sensor exceeds a third reference value, thereby preventing excessive chlorine exposure to aquatic organisms in the water tank. Claim 10 A water treatment device according to claim 6, further comprising at least one of a DOC sensor for measuring the dissolved organic carbon concentration of the treated water; or an ORP sensor for measuring the oxidation-reduction potential (ORP) of the treated water; wherein the power supply unit monitors the oxidative decomposition efficiency of the electrolysis unit based on the measurement value of the DOC sensor or the ORP sensor and adjusts the driving intensity of the electrolysis unit, and the power supply unit comprises at least two of the following: a normal mode in which the driving intensity of the electro-coagulation unit is set to a first intensity and the driving intensity of the electrolysis unit is set to a second intensity; an intensive coagulation mode in which the driving intensity of the electro-coagulation unit is increased to a third intensity higher than the first intensity; and an intensive sterilization mode in which the driving intensity of the electrolysis unit is increased to a fourth intensity higher than the second intensity; and wherein switching between the modes is performed based on user input or sensor measurement value. Claim 11 A water treatment device according to claim 1, wherein the electrolysis unit is linked to the polarity switching cycle of the electrocoagulation unit, so that the operation of the electrolysis unit is temporarily suspended or the current density is reduced while the polarity switching of the electrocoagulation unit is performed, thereby preventing temporary current fluctuations occurring during polarity switching from affecting the production of hypochlorous acid by the electrolysis unit.

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