System and method for treating high-concentration salt wastewater of secondary battery precursor manufacturing process

Abstract

A salt wastewater treatment system for treating high-concentration salt wastewater, according to an embodiment of the present invention, comprises: a first pretreatment part having a first oxidation-reduction part for decomposing and removing, by means of an oxidation-reduction reaction using an oxidizing agent and a reducing agent, at least a part of organic matter and inorganic salts contained in high-concentration salt wastewater when the high-concentration salt wastewater flows therein; a second pretreatment part into which primarily pretreated water pretreated in the first pretreatment part flows, and which has a second oxidation-reduction part that performs the additional decomposition of the organic matter and inorganic salts of the primarily pretreated water by means of a secondary oxidation-reduction reaction, and a water-softening part that removes hardness components by spraying radical water; and a main treatment part which has a desalination part for continuously performing reverse electrodialysis and bipolar electrodialysis, and into which secondarily pretreated water pretreated in the second pretreatment part flows so that secondarily pretreated water is desalinated in a non-evaporative manner, wherein the first and second oxidation-reduction parts each include an oxidation-reduction process part in which an oxidation reaction using the oxidizing agent and a reduction reaction using the reducing agent are simultaneously performed.

Description

High-concentration saline wastewater treatment system and method for secondary battery precursor manufacturing process

[0001] The present invention relates to a salt wastewater treatment system and method for treating high-concentration salt wastewater generated in processes such as the manufacturing of secondary battery precursors.

[0002] With the recent surge in demand for electric vehicles and energy storage systems (ESS), the secondary battery industry is experiencing rapid growth. Consequently, the treatment of wastewater generated during the secondary battery manufacturing process, particularly in the precursor manufacturing process, is emerging as a critical environmental issue. Secondary battery precursors are manufactured using metal compounds such as nickel (Ni), cobalt (Co), and manganese (Mn) as raw materials through chemical processes including hydrothermal synthesis, coprecipitation, and calcination. During this process, a large amount of process wastewater is generated at stages such as washing, neutralization, filtration, and drying. This wastewater (hereinafter referred to as precursor salt wastewater) is discharged in a mixed form containing reaction byproducts, unreacted raw materials, cleaning solutions, and neutralizing agents; on-site, it is primarily generated from washing tanks, filtration systems, neutralization tanks, and reactor discharge lines.

[0003] Unlike general inorganic industrial wastewater, precursor salt wastewater contains sodium ions (Na + ) and sulfate ions (SO4 2- It contains high concentrations of ), and in particular, sodium sulfate (Na2SO₄) accounts for a high proportion of about 15% in the wastewater. Generally, precursor salt wastewater has a pH of neutral to slightly alkaline and contains salts (Na2SO₄, NaCl, etc.), ammonia nitrogen (NH₃-N), and heavy metal ions (Ni 2+ , Co 2+ , Mn 2+Substances such as organic complexing agents and dispersants, as well as fine solids (SS), coexist. Furthermore, precursor salt wastewater is characterized by high levels of inorganic matter and inorganic compounds, while having relatively low levels of organic matter. Residual ammoniacal nitrogen and sulfates cause water quality deterioration upon discharge and lead to problems such as scaling, clogging, and corrosion in subsequent treatment processes. In particular, high concentrations of salts in precursor wastewater are unsuitable for biological treatment and are identified as a major cause of scaling and membrane fouling in physical treatment facilities, such as Mechanical Vapor Recompression (MVR) or Reverse Osmosis (RO).

[0004] Meanwhile, industrial sites generally adopt Advanced Oxidation Process (AOP)-based systems as a treatment technology for wastewater containing high concentrations of recalcitrant organic matter and high salinity (e.g., precursor salt wastewater). For example, oxidizing and decomposing organic amines and residual pollutants are attempted using oxidizing agents such as ozone (O3), hydrogen peroxide (H2O₂), UV, and photocatalysts. In subsequent stages, a flow equalization tank, an aeration tank, and a coagulation and sedimentation tank are connected, and the oxidative decomposition of organic matter proceeds by powerful oxidizing radicals in the AOP reaction tank. Related prior art includes Korean Registered Patents No. 10-1234567 and No. 10-2345678.

[0005] However, even in the case of the AOP process, high concentrations of sulfate ions (SO4) 2- ), sodium ions (Na +Oxidation efficiency drops sharply in precursor salt wastewater where sulfate, ammoniacal nitrogen (NH3-N), heavy metal ions, and fine solids are simultaneously present. Even when utilizing strong oxidative radicals, sodium sulfate, an inorganic salt, is not decomposed by oxidation reactions alone; instead, it causes scaling, membrane fouling, and fouling in subsequent treatment facilities such as MVR or EDR, thereby impairing the treatment efficiency and maintenance stability of the entire system. In particular, sulfate ions (SO4 2- ) can be converted into hydrogen sulfide (H2S) and degassed through a reduction reaction, but existing AOP processes have a technical limitation in that they cannot perform such a reduction reaction because they rely only on an oxidation reaction.

[0006] In addition, in conventional water softening processes, chemicals such as calcium hydroxide (Ca(OH)2) and sodium carbonate (Na2CO₃) are added to [reduce] calcium ions (Ca₂), which are hardness components. 2+ ) and magnesium ions (Mg 2+ Although the sodium ions were removed by precipitating them in the form of calcium carbonate (CaCO3) and magnesium hydroxide (Mg(OH)2), this resulted in a large amount of byproduct sludge and additional chemical and sludge treatment costs. Furthermore, there was a limitation in that the adverse effect of increasing sodium ions and sulfate ions during the chemical addition process increased the load on the downstream desalination process.

[0007] Therefore, precursor salt wastewater is a complex form of wastewater containing high concentrations of inorganic salts and recalcitrant pollutants; it is difficult to treat sufficiently using only existing industrial wastewater treatment or AOP-based advanced treatment technologies, and a new technological approach is required to effectively address these characteristics.

[0008]

[0009] The present invention aims to solve the problem that ammoniacal nitrogen, organic matter, and inorganic salts contained in high-concentration saline wastewater generated in processes such as the manufacturing of secondary battery precursors are not sufficiently decomposed or removed in existing wastewater treatment processes.

[0010] In addition, the present invention aims to treat high-concentration saline wastewater in an eco-friendly manner that enables simultaneous resource recovery and nitrogen reduction.

[0011] A salt wastewater treatment system for treating high-concentration salt wastewater according to an embodiment of the present invention comprises: a first pretreatment unit provided with a first oxidation-reduction unit that decomposes and removes at least a portion of organic matter and inorganic salts contained in the high-concentration salt wastewater through an oxidation-reduction reaction utilizing an oxidizing agent and a reducing agent when the high-concentration salt wastewater is introduced; and a second pretreatment unit provided with a second oxidation-reduction unit that performs additional decomposition of organic matter and inorganic salts in the first pretreatment water through a secondary oxidation-reduction reaction and a water softening unit that removes hardness components by spraying radical water, into which the primary pretreatment water pretreated in the first pretreatment unit is introduced. A desalination unit is provided to continuously perform reverse electrodialysis and bipolar electrodialysis, and a main treatment unit is provided to which secondary pre-treated water pre-treated in the second pre-treatment unit is introduced to perform desalination treatment of the secondary pre-treated water in a non-evaporative manner; wherein the first and second oxidation-reduction units include an oxidation-reduction process unit in which an oxidation reaction by the oxidizing agent and a reduction reaction by the reducing agent proceed simultaneously.

[0012] In one embodiment, the second pretreatment unit may further include a tank (T3) into which the first pretreatment water is introduced; and a first reverse electrodialysis unit (EDR) for separating and removing salt contained in the first treatment water into cations and anions.

[0013] In one embodiment, the second oxidation-reduction unit receives the first pre-treated water from the tank (T3), additionally decomposes organic matter and inorganic salts in the first pre-treated water through a secondary oxidation-reduction reaction, and then returns it to the tank (T3); the first reverse electrodialysis unit receives the first pre-treated water from the tank (T3), separates and removes salts contained in the first pre-treated water into cations and anions, and then returns it to the tank (T3); the tank (T3) forms a flow path that communicates in parallel with the second oxidation-reduction unit and the first reverse electrodialysis unit, so that the oxidation-reduction reaction of the second oxidation-reduction unit and the desalination reaction of the first reverse electrodialysis unit can be performed in parallel.

[0014] In one embodiment, the tank (T3) forms a flow path that communicates in parallel with the second oxidation-reduction unit, the first reverse electrodialysis unit, and the softening unit, so that the primary pretreated water, which has undergone oxidation-reduction and desalination treatment in the second oxidation-reduction unit and the first reverse electrodialysis unit, is softened through the softening unit and then flows back into the second oxidation-reduction unit and the first reverse electrodialysis unit through the tank (T3), thereby allowing the oxidation-reduction reaction, the desalination reaction, and the softening reaction to be performed in parallel on the tank (T3).

[0015] In one embodiment, the second pretreatment unit further comprises: a cooling unit that cools the primary pretreatment water introduced from the tank (T3); and a second nanobubble generating unit (NBG3) that generates a reaction gas in the form of nanobubbles required for a water softening reaction from an externally supplied gas and supplies it to the primary pretreatment water cooled by the cooling unit; and the water softening unit may receive the primary pretreatment water containing the reaction gas in the form of nanobubbles, spray radical water to remove hardness components, and then introduce it back into the tank (T3).

[0016] In one embodiment, the first pretreatment unit is further provided with a tank (T2) into which the high-concentration salt wastewater is introduced; and the first oxidation-reduction unit receives the high-concentration salt wastewater from the tank (T2), decomposes and removes at least a portion of the organic matter and inorganic salts of the high-concentration salt wastewater through an oxidation-reduction reaction, and then introduces it back into the tank (T2), and the high-concentration salt wastewater can be discharged from the tank (T2) and introduced into the second pretreatment unit.

[0017] In one embodiment, the filtration unit that filters fine particles is further included to which the primary pretreated water pretreated in the first pretreatment unit is introduced, and the primary pretreated water filtered in the filtration unit may be introduced into the second pretreatment unit.

[0018] In one embodiment, the system further includes an ammonia stripping unit that performs an ammonia stripping process on the high-concentration salt wastewater to remove at least a portion of the nitrogen components, and the high-concentration salt wastewater from which the nitrogen components have been removed in the ammonia stripping unit may be introduced into the first pretreatment unit.

[0019] In one embodiment, the ammonia stripping unit is provided with a tank (T1) into which the high-concentration salt wastewater is introduced; and an ammonia stripper that receives the high-concentration salt wastewater from the tank (T1), performs an ammonia stripping reaction, transfers the vaporized ammonia to a first deodorizing unit, and introduces the high-concentration salt wastewater from which ammonia has been removed back into the tank (T1); and the tank (T1) and the ammonia stripper may each be configured with two or more units in parallel.

[0020] In one embodiment, the ammonia stripping unit further comprises: a first nanobubble generating unit (NBG1) that generates a reaction gas in the form of nanobubbles required for an ammonia stripping reaction from an externally supplied gas and supplies it to the high-concentration salt wastewater; and a heating unit that raises the temperature of the high-concentration salt wastewater containing the reaction gas in the form of nanobubbles to increase the vaporization efficiency of ammonia in the high-concentration salt wastewater, and the ammonia stripper can receive the high-concentration salt wastewater whose temperature has been raised by the heating unit.

[0021] The present invention relates to a method performed in a brine wastewater treatment system for treating high-concentration brine wastewater according to the present embodiment, comprising: a first pretreatment step of receiving high-concentration brine wastewater into a first oxidation-reduction unit and decomposing and removing at least a portion of organic matter and inorganic salts contained in the high-concentration brine wastewater through an oxidation-reduction reaction utilizing an oxidizing agent and a reducing agent; and a second pretreatment step of receiving primary pretreated water pretreated in the first pretreatment step into a second oxidation-reduction unit, further decomposing organic matter and inorganic salts of the primary pretreated water through a secondary oxidation-reduction reaction, and removing hardness components by spraying radical water in a softening unit. and a main treatment step in which the secondary pretreated water pretreated in the second pretreatment step is introduced, and reverse electrodialysis and bipolar electrodialysis are continuously performed to perform desalination treatment of the secondary pretreated water without evaporation; wherein the first and second oxidation-reduction units are further characterized by performing an oxidation-reduction step in which an oxidation reaction by the oxidizing agent and a reduction reaction by the reducing agent proceed simultaneously.

[0022] According to the present invention, it is possible to simultaneously decompose and remove ammoniacal nitrogen, organic matter, and inorganic salts in high-concentration brine wastewater, thereby providing the advantage of efficiently reducing difficult-to-decompose pollutants that could not be resolved by existing wastewater treatment processes.

[0023] In addition, the present invention has the advantage of minimizing energy consumption and secondary pollution through a non-evaporative, resource-recycling, eco-friendly process.

[0024] FIG. 1 is a schematic diagram of a salt wastewater treatment system that treats high-concentration salt wastewater according to an embodiment of the present invention.

[0025] Figure 2 is data analyzing the concentration of each item constituting high-concentration salt wastewater according to an embodiment of the present invention.

[0026] FIG. 3 is a schematic diagram of an ammonia stripping section according to an embodiment of the present invention.

[0027] FIG. 4 is a schematic diagram of the first preprocessing unit according to an embodiment of the present invention.

[0028] FIG. 5 is a schematic diagram of an oxidation-reduction section according to an embodiment of the present invention.

[0029] FIG. 6 is a diagram illustrating the generation of an oxidizing agent according to an embodiment of the present invention.

[0030] FIG. 7 is a diagram illustrating the generation of a reducing agent according to an embodiment of the present invention.

[0031] FIG. 8 is a schematic diagram of a second preprocessing unit according to an embodiment of the present invention.

[0032] FIG. 9 is a schematic diagram of a first reverse electrodialysis unit according to an embodiment of the present invention.

[0033] FIG. 10 is a diagram illustrating the reverse electrodialysis process of the first reverse electrodialysis unit according to an embodiment of the present invention.

[0034] FIG. 11 is a conceptual diagram showing the packaging configuration of a desalination unit according to an embodiment of the present invention.

[0035] The various embodiments described in this document are illustrative for the purpose of clearly explaining the technical concept of the invention and disclosure, and are not intended to limit them to specific embodiments. The technical concept of the invention and disclosure includes various modifications, equivalents, alternatives, and embodiments selectively combined from all or part of each embodiment described in this document. Furthermore, the scope of rights of the technical concept of the invention and disclosure is not limited to the embodiments presented below or the specific descriptions thereof.

[0036] Terms used in this document, including technical or scientific terms, may have the meaning generally understood by those skilled in the art to which the invention and disclosure pertain.

[0037] Expressions used in this document, such as "includes," "may include," "is equipped," "may be equipped," "has," and "may have," imply that functions, operations, or components exist as the subject feature and do not exclude the existence of other additional features. In other words, such expressions should be understood as open-ended terms implying the possibility of including other embodiments.

[0038] Singular expressions used in this document may include the meaning of the plural form unless the context otherwise indicates, and this applies likewise to singular expressions described in the claims.

[0039] Expressions used in this document such as “A, B, and C,” “A, B, or C,” “A, B, and / or C,” or “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one of A, B, and / or C,” “at least one selected from A, B, and C,” “at least one selected from A, B, or C,” “at least one selected from A, B, and / or C,” etc., may mean each of the listed items or all possible combinations of the listed items. For example, “at least one selected from A and B” may refer to (1) A, (2) at least one of A, (3) B, (4) at least one of B, (5) at least one of A and at least one of B, (6) at least one of A and B, (7) at least one of B and A, and (8) all of A and B.

[0040] The expression "based on" as used in this document is used to describe one or more factors affecting an act or action of a decision or judgment described in the phrase or sentence containing such expression, and this expression does not exclude additional factors affecting said act or action of a decision or judgment.

[0041] As used in this document, the expression that a certain component (e.g., a first component) is "connected" or "connected" to another component (e.g., a second component) may mean not only that the said certain component is directly connected or connected to the said other component, but also that it is connected or connected through a new other component (e.g., a third component).

[0042] The expression "configured to" as used in this document may have meanings such as "set to," "capable of," "modified to," "made to," or "able to," depending on the context, and is distinguished from the meaning of "consist."

[0043] Various embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the accompanying drawings and the description thereof, identical or substantially equivalent components may be given the same reference numerals. Furthermore, in the description of the various embodiments below, the description of identical or corresponding components may be omitted, but this does not mean that such components are not included in the embodiments.

[0044] FIG. 1 is a schematic diagram of a salt wastewater treatment system (1) for treating high-concentration salt wastewater according to an embodiment of the present invention. Referring to FIG. 1, the salt wastewater treatment system (1) may include an ammonia stripping unit (10), a first pretreatment unit (20), a second pretreatment unit (30), a filtration unit (221), and a main treatment unit (40).

[0045] The salt wastewater treatment system (1) according to an embodiment of the present invention provides a process capable of effectively decomposing organic pollutants, removing suspended solids, and concentrating and separating salts through a combination of chemical and physical processes (oxidation-reduction reaction, radical water injection, nanobubble injection, electrodialysis desalination, etc.), even though the composition of the high-concentration salt wastewater generated in processes such as secondary battery precursor manufacturing is difficult to treat biologically due to ammoniacal nitrogen, non-biodegradable organic matter, and high concentration inorganic salts contained therein. In particular, the treated water produced by the salt wastewater treatment system (1) according to this embodiment has significantly reduced concentrations of ammoniacal nitrogen, salts, and other pollutants, and can be treated to a level where it can finally be mixed into or reused in a low-concentration wastewater treatment system within the factory. This can improve the continuity of wastewater management, resource circularity, and environmental efficiency within the workplace. The salt wastewater treatment system (1) is an eco-friendly process that strengthens the ESG management system and complies with environmental regulations. It can fundamentally solve the problems of salt effect and non-biodegradable organic matter in wastewater, while simultaneously providing a sustainable wastewater treatment solution that satisfies energy saving, resource recycling, and environmental friendliness.

[0046] In addition, when systematically establishing processes such as pretreatment (oxidation-reduction), water softening, desalination, and resource recovery considering the characteristics of high-concentration brine wastewater, each stage can be modularized, enabling stable operation and high-efficiency separation and recovery of contaminants even with changes in water quality and influent. Furthermore, this system enables real-time process monitoring and integrated control through an instrumentation and control system composed of a PLC (Programmable Logic Controller), HUB, SCADA (Supervisory Control And Data Acquisition), HMI (Human Machine Interface), and MCP (Control Panel), allowing key process variables such as flow rate, pressure, electrical conductivity, pH, and level to be acquired and managed in real-time as digital and analog signals, and enabling the recording and storage of operational data in mobile and remote environments.

[0047] FIG. 2 is data analyzing the concentrations of each component constituting high-concentration saline wastewater according to an embodiment of the present invention. Referring to FIG. 2, pH, TDS, salinity, and Na were analyzed for high-concentration saline wastewater generated in a secondary battery precursor manufacturing process. + , SO4 2- , Cl - This shows the results of the analysis on major items such as TN, NH3-N, and TOC. As confirmed in Figure 2, high-concentration salt wastewater is characterized by very high concentrations of sodium ions and sulfate ions, and accordingly, the concentration of inorganic salts accounts for most of the total pollution load. On the other hand, the content of organic matter (TOC, BOD) is relatively low, indicating that it is high-salinity, high-concentration complex wastewater that requires chemical and physical treatments in combination, as sufficient decomposition is difficult with biological treatment alone.

[0048] Such high-concentration salt wastewater contains inorganic ions (especially Na₂). + , SO4 2-Because efficient treatment is difficult with a single process due to the high concentration accumulation of ) and the presence of non-biodegradable organic matter, a pretreatment step combining processes such as oxidation-reduction, radical reaction, and electrodialysis in stages is essential depending on the characteristics of each contaminant component.

[0049] Hereinafter, each component of the salt wastewater treatment system (1) will be described in detail with reference to FIG. 1.

[0050] The ammonia stripping unit (10) may include a tank (T1) and an ammonia stripper (11). The ammonia stripping unit (10) is a dedicated treatment unit for efficiently removing ammoniacal nitrogen compounds contained in high-concentration salt wastewater generated during the secondary battery precursor manufacturing process. In an embodiment of the present invention, the ammonia stripping unit (10) is composed of an integrated system in which multiple components are organically linked, rather than a simple single piece of equipment, thereby ensuring improved treatment efficiency and stability compared to a conventional simple stripping process.

[0051] The ammonia stripping unit (10) can remove at least a portion of the nitrogen components by performing an ammonia stripping process on high-concentration salt wastewater. The high-concentration salt wastewater from which nitrogen components have been removed in the ammonia stripping unit (10) can be introduced into the first pretreatment unit (20). Here, the nitrogen component is ammoniacal nitrogen (NH4 + It may include -N), free ammonia (NH3-N), organic nitrogen compounds, and complexes thereof. The ammonia stripping process is a physicochemical treatment process that adjusts the pH of high-concentration salt wastewater to convert ammoniacal nitrogen into the form of free ammonia, and then removes the ammonia by transferring it to the gas phase through gas-liquid contact.

[0052] In an embodiment of the present invention, the ammonia stripping unit (10), unlike a conventional single-evaporation treatment process, applies a combination of nanobubble technology and temperature increase technology to reduce energy consumption and stably remove nitrogen components in wastewater. Additionally, since the process has a completely sealed structure, it can fundamentally prevent ammonia gas leakage or the generation of odors. Furthermore, the ammonia stripping unit (10) removes ammonia into the gaseous phase using only pH adjustment, nanobubble injection, and temperature control, without using chemical reactants. Consequently, by-products such as ammonium sulfate [(NH4)2SO4], which are generated in conventional acid-base reaction denitrification processes, are not produced. Accordingly, the ammonia stripping unit (10) does not require a separate sludge treatment or salt recovery process, and has an eco-friendly effect in that factors causing secondary pollution and increased operating costs are eliminated.

[0053] FIG. 3 is a schematic diagram of an ammonia stripping unit (10) according to an embodiment of the present invention.

[0054] Referring to FIG. 3, the ammonia stripping unit (10) comprises, in detail, a tank (T1) (collection tank A, collection tank B), an ammonia stripper (11(a), 11(b)), a first nanobubble generating unit (NBG1) (12(a), 12(b)), a heating unit (13(a), 13(b)), and a first deodorizing unit (14), and each component is connected continuously and cyclically to perform a degassing and deodorizing process to convert and remove ammoniacal nitrogen in high-concentration salt wastewater into gaseous ammonia (NH3).

[0055] High-concentration salt wastewater may be introduced into the tank (T1). The ammonia stripper (11) receives high-concentration salt wastewater from the tank (T1), performs an ammonia stripping reaction, transfers the vaporized ammonia to the first deodorizing unit (14), and can introduce the high-concentration salt wastewater from which ammonia has been removed back into the tank (T1).

[0056] The first nanobubble generating unit (NBG1) (12) can generate a reaction gas in the form of nanobubbles required for an ammonia stripping reaction from an externally supplied gas and supply it to high-concentration salt wastewater. The first nanobubble generating unit (NBG1) (12) can inject the reaction gas in the form of nanobubbles into the high-concentration salt wastewater to significantly increase the gas diffusion area within the wastewater, thereby improving the reaction rate.

[0057] The heating unit (13) can increase the temperature of the high-concentration salt wastewater containing nanobubble-shaped reaction gas to increase the vaporization efficiency of ammonia in the high-concentration salt wastewater. The heating unit (13) can be composed of a heating device such as a heat exchanger, an electric heater, a steam heater, or a heat pump, and can raise the temperature of the wastewater to a range of 40°C to 80°C.

[0058] The heating unit (13) can increase the temperature of the wastewater to shift the gas-liquid equilibrium of ammonia toward the gas phase according to Henry's law, thereby improving stripping efficiency. Additionally, the heating unit (13) can lower the viscosity of the wastewater to expand the diffusion and gas-liquid contact area of ​​the nanobubbles, thereby simultaneously improving the overall nitrogen removal rate and energy efficiency of the stripping reaction.

[0059] The ammonia stripper (11) can receive high-concentration salt wastewater whose temperature has been raised by the heating unit (13). The high-concentration salt wastewater heated in the heating unit (13) can be supplied to the upper part of the ammonia stripper (11) through a pipe. The heated high-concentration salt wastewater can promote an ammonia removal reaction by coming into contact with the stripping gas inside the ammonia stripper (11), and the higher the temperature, the greater the volatility of the ammonia, thereby improving the removal efficiency.

[0060] The temperature of the wastewater flowing into the ammonia stripper (11) can be monitored in real time, and the temperature can be automatically controlled for optimal stripping efficiency. In addition, multiple temperature sensors can be installed to maintain a uniform temperature distribution inside the stripper.

[0061] The first deodorizing unit (14) receives ammonia gas (NH3) vaporized from an ammonia stripper (11), removes odors, and performs detoxification treatment when discharged into the atmosphere. For example, the first deodorizing unit (14) may adopt one or more of the following: a wet deodorizing method using weakly acidic washing water, an adsorption deodorizing method using activated carbon or zeolite adsorbent, or an oxidation deodorizing method that converts NH3 into nitrogen (N2) and water vapor (H2O) using a catalytic oxidation reaction. In one embodiment, the first deodorizing unit (14) may be configured with a multi-stage wet washing layer and an adsorption layer in series to purify the vaporized ammonia step by step, thereby minimizing the emission of odors and harmful gases. The first deodorizing unit (14) configured in this way does not generate by-products and can prevent air pollution by treating the degassed ammonia in an environmentally friendly manner.

[0062] In the embodiment illustrated in FIG. 3, two or more tanks (T1) and ammonia strippers may each be configured in parallel. The ammonia stripping unit (10) may be a Dual Package module in which a first ammonia stripper (11(a)) and a second ammonia stripper (11(b)) are provided in parallel. The tank (T1) may be composed of a collection tank A and a collection tank B, and each collection tank may be connected to a corresponding stripping equipment via a communication structure. Specifically, collection tank A is connected to the first nanobubble generating unit (12(a)), the first heating unit (13(a)), and the first ammonia stripper (11(a)) to form a single module, and collection tank B is connected to the second nanobubble generating unit (12(b)), the second heating unit (13(b)), and the second ammonia stripper (11(b)) to form a single module, so that the two modules can be configured in parallel. High-concentration salt wastewater from which ammonia has been removed, which flows into each collection tank, can be introduced into the first pretreatment unit (20). Through this parallel configuration, each line can be operated alternately or simultaneously, allowing for continuous operation even during maintenance, improving stability against fluctuations in influent load, and increasing the processing capacity and reliability of the entire system.

[0063] The first pretreatment unit (20) may include a first oxidation-reduction unit (21), a tank (T1), and a sedimentation unit (22). The first pretreatment unit (20) may be designed to control decomposition and removal conditions suitable for each contaminant characteristic based on real-time measurement of various items. This is a very important factor for the rapid and stable treatment of high-concentration saline wastewater, which is difficult to treat biologically, particularly due to ammoniacal nitrogen, recalcitrant organic matter, and high concentrations of inorganic salts.

[0064] FIG. 4 is a schematic diagram of the first preprocessing unit (20) according to an embodiment of the present invention.

[0065] Referring to FIG. 4, the operational relationship of the configuration in which the detailed configurations of the first oxidation-reduction unit (21(a), 21(b)) and the precipitation unit (22) are linked can be confirmed. In this embodiment, the first oxidation-reduction unit (21) can be provided as an ARP, which is a device for the Advanced Redox Process.

[0066] The oxidation-reduction unit (ARP) according to the present embodiment applies advanced oxidation and reduction treatment technology and utilizes electrochemical and physical reactors to remove recalcitrant organic matter in high-concentration saline wastewater, and additionally enables the removal of salts such as Na2SO4. Here, the oxidation-reduction unit (ARP) simultaneously utilizes an oxidizing agent and a reducing agent, and SO4 2- Anions such as those mentioned above can be reduced and gasified for removal. For example, organic matter can be decomposed by powerful oxidizing agents such as hydroxyl radicals, and SO4 can be removed by highly active reducing agents such as hydrated electrons (e-aq). 2- The negative ions of the back can be gasified into H2S, etc. and discharged to the outside.

[0067] These oxidation and reduction processes can be performed simultaneously and continuously, and a continuous cyclic reaction can occur. For example, in wastewater where organic matter and salts have been significantly decomposed by oxidation, a certain amount of salts can be removed through reduction, and oxidation and reduction reactions can then occur continuously.

[0068] Compared to conventional AOPs, this oxidation-reduction unit (ARP) performs oxidation and reduction processes simultaneously, thereby significantly improving the removal of organic matter and salts, enhancing removal efficiency, and ensuring superior economic feasibility. Furthermore, since Na2SO4, the primary cause of scaling, can be minimized, the long-term reliability and stability of the process can be secured.

[0069] In the embodiment illustrated in FIG. 4, the first oxidation-reduction unit (21) for pretreatment of high-concentration salt wastewater may be a Dual Package module in which a first-1 oxidation-reduction unit (21(a)) and a first-2 oxidation-reduction unit (21(b)) are provided in parallel. The tank (T2) may be composed of a collection tank C and a collection tank D, and each collection tank may be connected to a corresponding ARP equipment in a communication structure. The first oxidation-reduction unit (21) is composed of two ARPs (21(a), 21(b)), and each ARP may communicate with collection tank C or collection tank D to perform parallel and cyclic organic decomposition operations.

[0070] The ARP equipment (21(a), 21(b)) is a facility in which oxidation and reduction functions are combined, and is referred to as HN-ARP. The HN-ARP can be configured to allow wastewater to be introduced and discharged bidirectionally from the tank (T1), and the ARP equipment (21(a), 21(b)) is not directly connected to the sedimentation unit (12), but can instead cyclically repeat feedback recovery and re-decomposition within the tank (T2) first.

[0071] This equipment connection structure for cyclic feedback recovery and re-decomposition ensures that the ARP equipment is not directly connected to the sedimentation unit (22), thereby preventing membrane fouling and ensuring stable operation of the equipment, as well as ease of maintenance such as replacement. In particular, the HN-ARP structure allows for the customization of the treatment performance of high-concentration salt wastewater by adjusting the operating time and decomposition intensity of the ARP through a cyclic connection with the tank (T2). That is, the HN-ARP is separated from the sedimentation unit (22) following the cyclic cycle in relation to the tank (T2), and this allows for the pretreatment performance to be secured according to the concentration of the high-concentration salt wastewater through the convenience of time control, which is the operating time of the ARP in the cyclic cycle.

[0072] As an example of ARP, the first oxidation-reduction unit (21) can decompose and remove at least some of the organic matter and inorganic salts contained in the high-concentration salt wastewater through an oxidation-reduction reaction using an oxidizing agent and a reducing agent when high-concentration salt wastewater is introduced.

[0073] FIG. 5 is a schematic diagram of an oxidation-reduction unit (21) according to an embodiment of the present invention.

[0074] The first oxidation-reduction unit (21) may include an oxidizing agent generating unit (212), a reducing agent generating unit (213), and an oxidation-reduction process unit (211). The oxidation-reduction process unit (211) is a configuration of equipment for simultaneously performing an oxidation reaction by an oxidizing agent and a reduction reaction by a reducing agent.

[0075] The oxidizing agent generating unit (212) can generate an oxidizing agent containing one or more types of radicals. In this embodiment, one or more types of radicals may include one or more of hydroxy radicals or superoxide anion radicals.

[0076] The oxidizing agent generating unit (212) can generate an oxidizing agent such as -OH, O2- and supply it to the oxidation-reduction process unit (211), and the reducing agent generating unit (213) can generate a reducing agent such as H2, H+, eaq and supply it to the oxidation-reduction process unit (211). The oxidation-reduction process unit (211) can receive the oxidizing agent and the reducing agent in parallel through separate pipes from the oxidizing agent generating unit (212) and the reducing agent generating unit (213), respectively. That is, the oxidation-reduction process unit (211) can be connected in parallel to the oxidizing agent generating unit (212) and the reducing agent generating unit (213). The oxidation-reduction process unit (211) is connected to the tank (T2) and can send the high-concentration salt wastewater treated in the oxidation-reduction process to the tank (T2). The structure in which the oxidation-reduction process section (211) is connected in parallel means a conduit configuration in which the oxidizing agent and the reducing agent can be efficiently supplied and reacted simultaneously.

[0077] FIG. 6 is a diagram illustrating the generation of an oxidizing agent according to an embodiment of the present invention. Referring to FIG. 6, the oxidizing agent generation unit (212) may include a coating electrode (2121), a UV lamp (2123), and an ozone generator (2122).

[0078] An active oxidizing agent may be generated in the oxidizing agent generating section (212). For example, the generated oxidizing agent may include a hydroxy radical (·OH), a superoxide anion radical (O2-), etc. These hydroxy radicals or superoxide anion radicals are powerful oxidizing agents with very high reactivity and can oxidize and decompose organic matter.

[0079] The coating electrode (2121) can generate hydroxyl radicals (·OH) by electrolyzing water contained in amine wastewater containing organic pollutants.

[0080] In this embodiment, the coated electrode (2121) may be an electrode coated with one or more selected from the group consisting of boron-doped diamond (BDD), platinum (Pt), ruthenium (Ru), iridium (Ir), RuO2, and IrO2. The UV lamp (2123) and the ozone generator (2122) may electrochemically generate an active oxidizing agent. For example, the active oxidizing agent may be generated in an ozone-based process by ultraviolet (UV) irradiation by the UV lamp (2123) and by the ozone (O3) generator (2122).

[0081] To summarize an example of an oxidizing agent generating unit (212), the oxidizing agent generating unit (212) may be an electrochemical reactor. The oxidizing agent generating unit (212) may include an electrode (2121) coated with a nanocatalyst, an ozone generator (2122), and a UV lamp (2123).

[0082] The nanocatalyst coated on the surface of the electrode (2121) has a structure in which nanoparticles are supported on a support. The support may be any one of zeolite, activated carbon, ceramic, or magnesium oxide, and the nanoparticles may be one or more of ruthenium (Ru), platinum (Pt), iridium (Ir), palladium (Pd), TiO2, RuO2, SiO2, MnO2, FeO(OH), MgO, and Ca(OH)2.

[0083] Ozone is generated in an ozone (O3) generator (2122), and a UV lamp (2123) that irradiates UV and an electrode (221) coated with a nanocatalyst on its surface is involved, and hydroxyl radicals and superoxide anion radicals can be generated according to reaction equations 1 to 5 below.

[0084] [Reaction Equation 1]

[0085] O3 + H2O + hv -> O2 + H2O2

[0086] [Reaction Equation 2]

[0087] H2O2+ hv -> ·OH + ·OH

[0088] [Reaction Equation 3]

[0089] H2O2+ e - aq ->·OH + ·OH

[0090] [Reaction Equation 4]

[0091] H2O + hv -> ·OH + H +

[0092] [Reaction Equation 5]

[0093] O2+ e - aq -> O2 ·-

[0094] The hydrogen ion (H), which is the product of the above reaction equation 4. + ) can be utilized when a reduction reaction occurs in the reducing agent generating unit (213), and hydrated electrons, which are reactants of reaction formulas 3 and 5, may also be generated in the reducing agent generating unit (213).

[0095] The reducing agent generating section (213) consists of hydrogen ions and hydrated electrons (e - aq A reducing agent including ). FIG. 7 is a diagram illustrating the generation of a reducing agent according to an embodiment of the present invention. Referring to FIG. 7, the reducing agent generating unit (213) may include a hydrogen gas storage unit (2131), a nanobubble generating unit (NBG2) (2132), a reducing agent generating unit (2133), and a plasma generating unit (2134).

[0096] The hydrogen gas storage unit (2131) supplies hydrogen gas (H2) to the reducing agent generating unit (2133).

[0097] The nanobubble generating unit (NBG2) (2132) can generate a reaction gas in the form of nanobubbles required for an oxidation-reduction reaction from an externally supplied gas and supply it to high-concentration salt wastewater. In this embodiment, the externally supplied gas may consist of one or more selected from the group consisting of ozone (O3), liquid carbon dioxide (L-CO2), liquid ammonia (L-NH3), hydrogen (H2), and oxygen (O2).

[0098] The reducing agent generating unit (2133) can generate a reducing agent. The plasma generating unit (2134) can induce the generation of a reducing agent by applying plasma to nanobubbled hydrogen gas.

[0099] Referring to FIG. 7, an example of a reducing agent generating unit (213) is described as follows: hydrogen gas (H2) is supplied from a hydrogen gas storage unit (2131) to a reducing agent generating unit (2133), and at this time, the hydrogen gas is supplied after being nanobubbled through a nanobubble generating unit (2132). In the reducing agent generating unit (2133), underwater plasma generated through a plasma generator (2134) or ultrasound generated by an ultrasound generator (not shown) is applied to the nanobubbled hydrogen gas, thereby producing hydrogen ions (H + ) and hydrated electrons (e - aqReducing agents such as ) can be generated. The generation of reducing agents can be achieved by the following reaction scheme 6.

[0100] [Reaction Equation 6]

[0101] H2O + plasma -> H + + OH - + e - aq

[0102] These reducing agents are highly active reducing agents, such as SO4 2- It can remove ions such as and decompose organic matter in an oxidized state.

[0103] In the oxidation-reduction process section (211), oxidizing agents can decompose at least a portion of the organic matter contained in the incoming wastewater. Additionally, in the oxidation-reduction process section (211), reducing agents can degas and remove at least a portion of the salt contained in the wastewater, or decompose at least a portion of the organic matter in an oxidized state.

[0104] For example, SO4 from Na2SO4 contained in wastewater 2- The ions can be removed by degassing by being converted into hydrogen sulfide (H2S) by the following reaction equation 7.

[0105] [Reaction Equation 7]

[0106] SO4 2- + 10H + + 8e - aq -> H2S + 4H2O

[0107] The reaction occurring in the oxidation-reduction process section (211) is an oxidation-reduction reaction in which an oxidation reaction by the generated oxidizing agent and a reduction reaction by the generated reducing agent proceed simultaneously. In the oxidation-reduction reaction, the oxidation reaction and the reduction reaction occur simultaneously and proceed continuously. In this process, the oxidizing agent and the reducing agent are repeatedly generated and destroyed.

[0108] Due to these oxidation-reduction reactions, some organic matter or salts are decomposed, which can improve the efficiency of subsequent processes. Additionally, the permanent removal of some organic matter or salts can further enhance the efficiency of subsequent processes and reduce costs. Furthermore, the removal of Na2SO4 can minimize scaling phenomena that cause problems for processes and equipment.

[0109] The oxidation-reduction process section (211) uses hydroxyl radicals (-OH), superoxide anions (O2-), etc. supplied from the oxidizing agent generating section (212) and hydrated electrons (e) supplied from the reducing agent generating section (113). aq ), hydrogen ion (H + Oxidation-reduction reactions can be performed by simultaneously utilizing reducing agents such as ), hydrogen (H2), etc. Among the components of raw water contained in industrial water, TOC, TP, TN, SO4 2- Non-biodegradable organic matter and salts such as can be decomposed by an oxidizing agent, and anions can be reduced by a reducing agent and discharged as gas.

[0110] In particular, in the oxidation-reduction process section (211), oxidation and reduction reactions proceed simultaneously, so that TOC (Total Organic Carbon) can be rapidly and effectively reduced, and TP (Total Phosphorus), TN (Total Nitrogen), SO4 2 Major contaminants such as sulfate ions can be significantly removed. pH, TDS, and Cl contained in the raw water components - Various items such as SS can also be appropriately treated through oxidation-reduction reactions.

[0111] The oxidation-reduction process unit (211), which is the ARP device of this embodiment, has the characteristic of continuously repeating advanced oxidation and reduction treatments, thereby significantly improving the efficiency of removing organic matter and salts compared to conventional AOPs. As a result, SO4, which causes scaling problems in amine wastewater 2- , Na+, etc. can be effectively reduced.

[0112] Referring again to FIGS. 1 and FIGS. 5, high-concentration salt wastewater is introduced into the tank (T2). The first oxidation-reduction unit (21) receives high-concentration salt wastewater from the tank (T2), decomposes and removes at least some of the organic matter and inorganic salts of the high-concentration salt wastewater through an oxidation-reduction reaction, and then introduces it back into the tank (T2).

[0113] The sedimentation unit (22) receives high-concentration salt wastewater in which organic matter and inorganic salts have been decomposed in the tank (T2) and can precipitate and remove suspended solids or decomposed organic matter and inorganic salts. The sedimentation unit (22) can be controlled to remove solids (SS) and heavy metal ions in the wastewater and to maintain an appropriate pH for the stable production of crystalline salts (BaSO4, etc.). In this embodiment, pH adjustment can be performed by injecting liquid carbon dioxide (L-CO2), and the settling of suspended solids and the aggregation of fine particles can be promoted by electro-coagulation (electro-coagulant) or chemical coagulation (PAC injection). The precipitated solids are concentrated in the form of sludge in a concentration tank, then dewatered by a filter press to be separated into solid sludge, and the dewatered solids can be stored in a ton bag or a roll-off box. The supernatant generated after dehydration can be recirculated to a resource recovery process to recover valuable metals (e.g., Ni, Co, Mn, etc.) or transferred to a subsequent processing stage.

[0114] The sedimentation section (22) may include a sedimentation tank (222) and a coagulation-dewatering tank (223).

[0115] The sedimentation tank (222) receives high-concentration salt wastewater filtered through the filtration unit (221), separates and settles suspended solids, and can discharge the high-concentration salt wastewater from which suspended solids have been separated to the second pretreatment unit (30) as primary treated water. In this embodiment, the sedimentation tank (222) may be provided as a lamella clarifier (LC). A lamella clarifier (LC) is a water treatment device that effectively separates and settles solid particles (such as suspended solids) from a liquid by utilizing inclined plates or inclined tubes. In a lamella clarifier (LC), a plurality of thin parallel plates (or tubes) with an inclined angle are arranged inside the tank, so that when water enters, solids come into contact with each plate (or tube), increasing the settling area, and the settled solids fall down by gravity and collect as sludge. At this time, BaCl2 may be added to the lamella clarifier (LC). In the sedimentation tank (222), a precipitate can be formed by H2S / BaCl2. For the reaction formula for the formation of the precipitate, refer to Reaction Formula 8.

[0116] [Reaction Equation 8]

[0117] 2Na + H2S -> Na2S(s) + 2H +

[0118] BaCl2 + Na2SO4 → BaSO4(s) + 2NaCl

[0119] Consequently, the settled solids are transferred to the coagulation-dewatering tank (223), and the remaining pretreated high-concentration salt wastewater is transferred to the second pretreatment unit (30).

[0120] The coagulation-dewatering tank (223) receives amine wastewater from which suspended solids have been separated in the sedimentation tank (222), performs additional pretreatment through chemical coagulation and physical filtering, and then circulates it to the tank (T2). In this embodiment, the coagulation-dewatering tank (223) can perform CC (Chemical Coagulation) & APF (Automatic Pressure Filter) treatment. CC treatment is a device in which a coagulant (FeCl3, PAC, etc.) or a coagulant (sulfate, alum, etc.) is injected, allowing particles to chemically bond (charge neutralization) and grow into large, heavy clumps (floc). The grown flocs are separated through a sedimentation or filtration process, and the turbidity of the treated water can be significantly reduced. The APF is an automatic pressure filter, which may be a device containing filter media (cloth, filter, plate, etc.) inside the machine and filters out solids by passing the material to be treated through pressure (pump, mechanical). The coagulation-dehydration tank (223) is equipment for neutralizing the charge of contaminants to cause them to clump together, and then forming flocs so that they can be easily separated and removed through sedimentation or filtration processes.

[0121] The filtration unit (221) receives primary pre-treated water pre-treated in the first pre-treatment unit (20) and can filter fine particles.

[0122] The filtration unit (221) according to the present embodiment may be provided as a ceramic ultrafiltration (UF) membrane. The ceramic ultrafiltration membrane may have a pore size of about 0.1 μm and can selectively filter and remove fine particles and high-molecular-weight organic substances in wastewater. The ceramic filtration membrane has excellent chemical resistance and heat resistance, is easy to regenerate by acid-alkali cleaning, and has low fouling on the membrane surface, allowing it to maintain stable filtration performance for a long period. In addition, the ceramic ultrafiltration unit does not undergo structural deformation or corrosion even in an environment of high-concentration salt wastewater based on inorganic substances, which has the effect of reducing the load of subsequent processes.

[0123] Referring again to FIG. 1, the second pretreatment unit (30) may include a tank (T3), a second oxidation-reduction unit (31), a first reverse electrodialysis unit (EDR1) (32), and a water softening unit (33). The second pretreatment unit (30) receives primary pretreatment water pretreated in the first pretreatment unit (20), and may be provided with a second oxidation-reduction unit that performs additional decomposition of organic matter and inorganic salts of primary pretreatment water through a secondary oxidation-reduction reaction, and a water softening unit (33) that removes hardness components by spraying radical water.

[0124] Primary pre-treated water can be introduced into the tank (T3).

[0125] The second oxidation-reduction unit (31) receives primary pretreatment water from the tank (T3), and through a secondary oxidation-reduction reaction, additionally decomposes organic matter and inorganic salts in the primary pretreatment water and returns it to the tank (T3). The first reverse electrodialysis unit (EDR1) (32) receives primary pretreatment water from the tank (T3), separates and removes salts contained in the primary pretreatment water into cations and anions, and returns it to the tank (T3). It is noteworthy that the tank (T3) forms a flow path that communicates in parallel with the second oxidation-reduction unit (31) and the first reverse electrodialysis unit (EDR1) (32), so that the oxidation-reduction reaction of the second oxidation-reduction unit (31) and the desalination reaction of the first reverse electrodialysis unit (EDR1) (32) are performed in parallel. After this, secondary pre-treated water can be discharged from the tank (T3) and flow into the main treatment unit (40).

[0126] Meanwhile, in conventional water softening processes, chemicals such as Ca(OH)2 and Na2CO3 were added to remove hardness components; however, this resulted in excessive chemical costs and by-products due to precipitates (such as CaCO3) generated after the reaction. In the second pretreatment unit (30) of the present invention, the second oxidation-reduction unit (31) and the first reverse electrodialysis unit (EDR1) (32) are organically linked, thereby allowing Ca in wastewater to be removed without the addition of chemicals.2+ , Mg 2+ Hardness components such as those of the body can be removed by converting and precipitating them into an insoluble form. This chemical-free water softening process can implement an eco-friendly treatment system in which hardness components are repeatedly removed through a continuous circulation reaction while minimizing the generation of by-products and sludge. As a result, chemical costs can be reduced by more than 50% and installation space can be saved through the water softening process of the second pretreatment unit (30) according to the embodiment of the present invention.

[0127] In an embodiment of the present invention, the tank (T3) forms a flow path that communicates in parallel with the second oxidation-reduction unit (31), the first reverse electrodialysis unit (EDR1) (32), and the water softening unit (33), so that the primary pretreatment water, which has undergone oxidation-reduction and desalination treatment in the second oxidation-reduction unit (31) and the first reverse electrodialysis unit (EDR1) (32), is softened through the water softening unit (33) and then flows back into the second oxidation-reduction unit (31) and the first reverse electrodialysis unit (EDR1) (32) through the tank (T3), thereby allowing the oxidation-reduction reaction, the desalination reaction, and the water softening reaction to be performed in parallel on the tank (T3). According to this configuration, the second pretreatment unit (30) centered on the tank (T3) forms a circulation structure in which the oxidation-reduction, desalination, and water softening processes are repeatedly circulated, thereby enabling the stable removal of residual pollutants in the wastewater.

[0128] FIG. 8 is a schematic diagram of a second preprocessing unit (30) according to an embodiment of the present invention.

[0129] Referring to FIG. 8, the second pretreatment unit (30) includes, in detail, a tank (T3) (collection tank E, collection tank F), a second oxidation-reduction unit (31(a), 31(b)), a first reverse electrodialysis unit (EDR1) (32(a), 32(b)), a water softening unit (33(a), 33(b)), a cooling unit (34(a), 34(b)), a second nanobubble generation unit (NBG3) (35(a), 35(b)), and a second deodorization unit (36). Each component is connected continuously and cyclically to further decompose, desalinate, and soften residual organic matter and inorganic salts in the first pretreatment water, thereby reducing the load on the main treatment unit (40) and performing a pretreatment process to purify the water to a stable quality.

[0130] The cooling unit (34) can cool the primary pre-treated water introduced from the tank (T3). The cooling unit (34) can perform the function of adjusting the temperature of the primary pre-treated water pre-treated in the first pre-treatment unit (20) to a temperature optimized for the subsequent process.

[0131] The cooling unit (34) can provide temperature conditions to optimize reaction efficiency in the subsequent processes, the nanobubble generation unit (NBG) (35) and the softening unit (33). The generation efficiency and stability of nanobubbles are affected by temperature, and generally, more stable nanobubbles can be formed at lower temperatures. Additionally, the cooling unit (34) can maintain an appropriate temperature range to control radical reactions, and excessive temperature can cause excessive generation of radicals or unwanted side reactions.

[0132] The second nanobubble generating unit (NBG3) (35) can generate a reaction gas in the form of nanobubbles required for the softening reaction from a gas supplied from the outside and supply it to the primary pre-treated water cooled by the cooling unit (34). The second nanobubble generating unit (NBG3) (35) of the second pre-treatment unit (30) may utilize the aforementioned nanobubble generating unit (NBG2) (2132).

[0133] The microbubbles generated by the second nanobubble generating unit (NBG3) (35) have a larger surface area and a longer residence time compared to ordinary bubbles, and generate a high charge density upon collapse, so the transfer efficiency of dissolved oxygen and carbon dioxide during the softening reaction can be improved. Accordingly, Ca in the wastewater 2+ , Mg 2+ Hardness components react with radical water and precipitate in an insoluble form, and the oxidizing power of the radicals acts simultaneously to induce partial decomposition of residual organic matter and aggregation of fine particles. In addition, nanobubble injection can suppress the adhesion of scale that may form on the membrane surface due to micro-shock waves and charge effects generated upon bubble collapse, and can improve the overall efficiency and long-term operational stability of the softening unit (33). Thus, the second pretreatment unit (30) can improve the efficiency of removing hardness components through the action of the second nanobubble generation unit (NBG3) (35), and the scaling and membrane fouling of the subsequent desalination unit (EDR, BPED) can be suppressed.

[0134] The softening unit (33) receives primary pre-treated water containing nanobubble-shaped reaction gas, sprays radical water to remove hardness components, and then returns it to the tank (T3). The softening unit (33) removes hardness components (Ca) in the wastewater in an environment where radical water is sprayed. 2+ , Mg 2+ The hardness component (etc.) can be converted into an insoluble compound form and removed. During the reaction process, the radical water forms active species with a high oxidation-reduction potential, causing the hardness component to be precipitated in the form of carbonates or hydroxides instead of existing in a dissolved state. The precipitated hardness product is separated by gravity or fluid flow, and the treated supernatant is circulated back into the tank (T3) and transferred to the next treatment stage. Through this circulation structure, the softening unit (33) prevents the accumulation of the hardness component and can maintain a continuous and stable softening reaction throughout the entire second pretreatment unit (30).

[0135] In the embodiment illustrated in FIG. 8, two or more second pretreatment lines may be configured in parallel. The tank (T2) is composed of a collection tank E and a collection tank F, and each collection tank may be connected to a corresponding second pretreatment detailed configuration in a communication structure to form a single circulation module.

[0136] Specifically, the collection tank E is connected to the second oxidation-reduction unit (31(a)), the first-first reverse electrodialysis unit (32(a)), the cooling unit (34(a)), the nanobubble generation unit (35(a)), and the water softening unit (33(a)) to form a single module, and the collection tank F is connected to the second oxidation-reduction unit (31(b)), the first-second reverse electrodialysis unit (32(b)), the cooling unit (34(b)), the nanobubble generation unit (35(b)), and the water softening unit (33(b)) to form a single module, so that the two modules can be configured in parallel. The two modules are configured in parallel so that alternating or simultaneous operation is possible, and the pre-treated water processed in each line flows into a common second deodorization unit (36) to remove residual gas or odor components. According to this parallel circulation structure, the second pretreatment unit (30) can continuously perform stable water quality adjustment and removal of hardness components even with load fluctuations of high-concentration salt wastewater, and can operate continuously even during maintenance, thereby improving the operational stability and efficiency of the entire system.

[0137] The second deodorizing unit (36) is a device for removing vaporized gas and odor components generated during the water softening process of the second pretreatment unit (30), and can absorb and purify ammonia and odorous gas in the gaseous phase using the same principle as the first deodorizing unit (14) described above.

[0138] Referring again to FIG. 1, the main treatment unit (40) may include a tank (T4) and a desalination unit (41). The main treatment unit (40) is provided with a desalination unit (41) that continuously performs reverse electrodialysis and bipolar electrodialysis, and the secondary pre-treated water pre-treated in the second pre-treatment unit (30) is introduced to perform desalination treatment of the secondary pre-treated water in a non-evaporative manner. The main treatment unit (40) can be understood as a system module configured to perform the desalination treatment of the introduced secondary pre-treated water in a short period of time.

[0139] The tank (T4) can receive secondary pre-treated water processed in the second pre-treatment unit (30).

[0140] The desalination unit (41) can continuously perform reverse electrodialysis (EDR) and bipolar electrodialysis (BPED). By continuously performing reverse electrodialysis and bipolar electrodialysis, the desalination unit (41) can separate and remove residual ionic salts in high-concentration salt wastewater step by step. The continuous operation structure of EDR and BPED of the desalination unit (41) can reduce energy consumption by more than 50% compared to conventional evaporation and crystallization-based concentration methods, and since wastewater is treated without evaporation, secondary steam generation or cooling water consumption is not required. In addition, the acid (H2SO4) and alkali (NaOH or NaHCO3) generated in the BPED process can be recovered as recyclable resources.

[0141] Since the main treatment unit (40) is a closed recovery structure in which salt concentration and resource recovery occur simultaneously, no salt sludge or crystal by-products are generated, and the efficiency of linkage to the downstream resource recovery facility is high, so an eco-friendly and economical zero liquid discharge treatment system (ZLD, Zero Liquid Discharge) can be implemented.

[0142] The desalination unit (41) may include a second reverse electrodialysis unit (EDR2) (411) and a bipolar electrodialysis unit (413). In this embodiment, the desalination unit (41) may be provided with a structure in which the second reverse electrodialysis unit (EDR2) (411) and the bipolar electrodialysis unit (413) are connected in series.

[0143] FIG. 9 is a schematic diagram of a second reverse electrodialysis unit (EDR2) (411) according to an embodiment of the present invention.

[0144] FIG. 10 is a diagram illustrating the reverse electrodialysis process of the second reverse electrodialysis unit (EDR2) (411) according to an embodiment of the present invention.

[0145] The second reverse electrodialysis unit (EDR2) (411) comprises an anode electrode (4112) and a cathode electrode (4115) facing each other, one or more cation exchange membranes (CEM) (4113) located between the anode electrode (4112) and the cathode electrode (4115), one or more anion exchange membranes (AEM) (4114), and one or more spacers between them. Additionally, the second reverse electrodialysis unit (EDR2) (411) comprises a first endplate (4111) located on one side of the anode electrode (4112) and a second endplate (4116) located on one side of the cathode electrode (4115).

[0146] FIG. 9 is a simplified drawing of the second reverse electrodialysis unit (EDR2) (411), and shows the stacked structure of the anode electrode (4112), cathode electrode (4115), cation exchange membrane (4113), and anion exchange membrane (4114).

[0147] Referring to FIG. 10, Na2SO4 passes through the second reverse electrodialysis unit (EDR2) (411), and Na + Ions and SO4 2-It is separated into ions and can be separated and removed according to charge (desalt). Although only the process of desalting Na2SO4 is illustrated in the drawing, the examples are not limited thereto, and other salts can also be separated and removed.

[0148] The bipolar electrodialysis unit (413) has a structure in which a cation exchange membrane, an anion exchange membrane, and a bipolar membrane are alternately stacked. When an electric field is applied, it generates an acid (H) and a base (OH) using a water splitting reaction, and can regenerate and recover acid and alkali solutions by separating and converting salts in wastewater. The bipolar electrodialysis unit (413) can recover H2SO4 and NaOH by treating wastewater concentrated in the second reverse electrodialysis unit (EDR2) (411). The treatment unit (40) according to the present invention can increase the resource recovery efficiency by more than 20% through the recovery of H2SO4 and NaOH.

[0149] FIG. 11 is a conceptual diagram showing the packaging configuration of a desalination unit according to an embodiment of the present invention. Referring to FIG. 11, the second reverse electrodialysis unit (EDR2) (411) and the bipolar electrodialysis unit (413) can be implemented in a modularized packaging structure to optimize installation space and improve operational efficiency.

[0150] First, the second reverse electrodialysis unit (EDR2) (411) and the bipolar electrodialysis unit (413) are configured as modular units and can be stacked in a stack form. Multiple stacks configured in this way can be installed within a vertical tower structure (Unit Tower) and arranged in a vertical direction, allowing the entire desalination facility to be integrated into a compact space. According to this embodiment, the installation area can be significantly reduced compared to the existing flat facility structure, and it can be implemented as a packaging structure that facilitates the expansion of unit modules or maintenance depending on site conditions.

[0151] In another embodiment of the present invention, a method performed in a salt wastewater treatment system for treating high-concentration salt wastewater may include: a first pretreatment step of receiving high-concentration salt wastewater into a first oxidation-reduction unit and decomposing and removing at least some of the organic matter and inorganic salts contained in the high-concentration salt wastewater through an oxidation-reduction reaction utilizing an oxidizing agent and a reducing agent; a second pretreatment step of receiving primary pretreated water pretreated in the first pretreatment step into a second oxidation-reduction unit, further decomposing the organic matter and inorganic salts of the primary pretreated water through a secondary oxidation-reduction reaction, and removing hardness components by spraying radical water in a softening unit; and a main treatment step of receiving secondary pretreated water pretreated in the second pretreatment step and continuously performing reverse electrodialysis and bipolar electrodialysis to perform desalination treatment of the secondary pretreated water in a non-evaporative manner.

[0152] The first pretreatment step may refer to the wastewater treatment step performed in the aforementioned first pretreatment unit (20). The second pretreatment step may refer to the wastewater treatment step performed in the aforementioned second pretreatment unit (30). Furthermore, the main treatment step may refer to the wastewater treatment step performed in the aforementioned main treatment unit (40).

[0153] Although the present invention has been described in detail above through representative embodiments, those skilled in the art will understand that various modifications can be made to the above-described embodiments within the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the claims set forth below as well as all modifications or variations derived from the claims and equivalent concepts.

[0154] [Explanation of the symbol]

[0155] 1: Brine Wastewater Treatment System 10: Ammonia Stripping Unit

[0156] 11: Ammonia stripper 12: First nanobubble generation unit (NBG1)

[0157] 13: Heating section 14: First deodorizing section

[0158] 20: 1st Pretreatment Unit 21, 31: 1st Oxidation-Reduction Unit

[0159] 211: Oxidation-Reduction Process Section 212: Oxidizing Agent Generation Section

[0160] 2121: Coated electrode 2122: Ozone generator

[0161] 2123: UV lamp 213: Reducing agent generating unit

[0162] 2131: Hydrogen gas storage unit 2132: Nanobubble generation unit (NBG2)

[0163] 2133: Reducing Agent Generation Unit 2134: Plasma Generation Unit

[0164] 22: Sedimentation unit 221: Filtration unit

[0165] 222: Sedimentation tank 223: Coagulation-dewatering tank

[0166] 30: 2nd Pretreatment Unit 32: 1st Reverse Electrodialysis Unit (EDR1)

[0167] 33: Water softening section 34: Cooling section

[0168] 35: 2nd Nanobubble Generation Unit (NBG3) 36: 2nd Deodorization Unit

[0169] 40: Main processing unit 41: Desalination unit

[0170] 411: Reverse Electrodialysis Unit 2 (EDR2) 413: Bipolar Electrodialysis Unit (BPED)

[0171] The present invention can be utilized in wastewater treatment processes by simultaneously decomposing and removing ammoniacal nitrogen, organic matter, and inorganic salts in high-concentration brine wastewater through a non-evaporative, resource-recycling, eco-friendly process.

Claims

1. In a brine wastewater treatment system for treating high-concentration brine wastewater, A first pretreatment unit provided with a first oxidation-reduction unit that, when the above-mentioned high-concentration salt wastewater is introduced, decomposes and removes at least a portion of organic matter and inorganic salts contained in the above-mentioned high-concentration salt wastewater through an oxidation-reduction reaction utilizing an oxidizing agent and a reducing agent; and A second pretreatment unit into which primary pretreatment water pretreated in the first pretreatment unit is introduced, and which is provided with a second oxidation-reduction unit that performs additional decomposition of organic matter and inorganic salts of the primary pretreatment water through a secondary oxidation-reduction reaction, and a water softening unit that removes hardness components by spraying radical water; and A desalination unit is provided to continuously perform reverse electrodialysis and bipolar electrodialysis, and a main treatment unit is provided to receive secondary pretreated water pretreated in the second pretreatment unit and perform desalination treatment of the secondary pretreated water in a non-evaporative manner; comprising The above first and second oxidation-reduction units are, A salt wastewater treatment system characterized by including an oxidation-reduction process section in which an oxidation reaction by the oxidizing agent and a reduction reaction by the reducing agent proceed simultaneously.

2. In Paragraph 1, The above second preprocessing unit is, A salt wastewater treatment system characterized by further comprising: a tank (T3) into which the above-mentioned primary pretreatment water is introduced; and a first reverse electrodialysis unit (EDR) for separating and removing salt contained in the above-mentioned primary treatment water into cations and anions.

3. In Paragraph 2, The above second oxidation-reduction unit is, The primary pre-treated water is received from the tank (T3), and the organic matter and inorganic salts of the primary pre-treated water are further decomposed through a secondary oxidation-reduction reaction and then introduced back into the tank (T3). The above-mentioned first reverse electrodialysis unit is, The primary pretreatment water is received from the tank (T3), the salt contained in the primary pretreatment water is separated into cations and anions and removed, and then the water is introduced back into the tank (T3). The above tank (T3) is, A salt wastewater treatment system characterized by forming a flow path that communicates in parallel with the second oxidation-reduction section and the first reverse electrodialysis section, so that the oxidation-reduction reaction of the second oxidation-reduction section and the desalination reaction of the first reverse electrodialysis section are performed in parallel.

4. In Paragraph 2, The above tank (T3) is, A salt wastewater treatment system characterized by forming a flow path that communicates in parallel with the second oxidation-reduction unit, the first reverse electrodialysis unit, and the softening unit, wherein the primary pretreated water, which has undergone oxidation-reduction and desalination treatment in the second oxidation-reduction unit and the first reverse electrodialysis unit, is softened through the softening unit and then flows back into the second oxidation-reduction unit and the first reverse electrodialysis unit through the tank (T3), so that oxidation-reduction, desalination, and softening reactions are performed in parallel on the tank (T3).

5. In Paragraph 2, The above second preprocessing unit is, A cooling unit for cooling the primary pre-treated water introduced from the tank (T3); and a second nanobubble generating unit (NBG3) for generating a reaction gas in the form of nanobubbles required for a water softening reaction from a gas supplied from the outside and supplying it to the primary pre-treated water cooled by the cooling unit are further provided. The above-mentioned softening unit is, A salt wastewater treatment system characterized by receiving primary pretreatment water containing the above-mentioned nanobubble-shaped reaction gas, spraying radical water to remove hardness components, and then introducing it back into tank (T3).

6. In Paragraph 1, The above first preprocessing unit is, A tank (T2) into which the above-mentioned high-concentration salt wastewater flows is further provided, The first oxidation-reduction unit receives the high-concentration salt wastewater from the tank (T2), decomposes and removes at least a portion of the organic matter and inorganic salts of the high-concentration salt wastewater through an oxidation-reduction reaction, and then returns it to the tank (T2). A salt wastewater treatment system characterized by the high concentration salt wastewater being discharged from the above tank (T2) and flowing into the above second pretreatment unit.

7. In Paragraph 6, It further includes a filtration unit that filters fine particles into which the primary pretreated water pretreated in the first pretreatment unit is introduced, and In the above second preprocessing unit, A salt wastewater treatment system characterized by the inflow of primary pre-treated water filtered in the above-mentioned filtration unit.

8. In Paragraph 1, It further includes an ammonia stripping unit that performs an ammonia stripping process on the above-mentioned high-concentration salt wastewater to remove at least a portion of the nitrogen components; In the above-mentioned first preprocessing unit, A salt wastewater treatment system characterized by the inflow of the high-concentration salt wastewater from which nitrogen components have been removed in an ammonia stripping section.

9. In Paragraph 8, The above ammonia stripping unit is, The above-mentioned high-concentration salt wastewater is introduced into a tank (T1); and An ammonia stripper is provided that receives the high-concentration salt wastewater from the tank (T1), performs an ammonia stripping reaction, transfers the vaporized ammonia to a first deodorization unit, and introduces the high-concentration salt wastewater from which ammonia has been removed back into the tank (T1). A salt wastewater treatment system characterized by having at least two tanks (T1) and ammonia strippers configured in parallel.

10. In Paragraph 9, The above ammonia stripping unit is, A first nanobubble generating unit (NBG1) that generates externally supplied gas into a reaction gas in the form of nanobubbles required for an ammonia stripping reaction and supplies it to the high-concentration salt wastewater; and A heating unit is further provided to increase the temperature of high-concentration salt wastewater containing a reaction gas in the form of nanobubbles, thereby increasing the vaporization efficiency of ammonia in the high-concentration salt wastewater. A salt wastewater treatment system characterized by the above ammonia stripper receiving high-concentration salt wastewater whose temperature has been raised by the above-mentioned heating unit.

11. A method performed in a brine wastewater treatment system for treating high-concentration brine wastewater, A first pretreatment step of receiving high-concentration salt wastewater into a first oxidation-reduction section and decomposing and removing at least some of the organic matter and inorganic salts contained in the high-concentration salt wastewater through an oxidation-reduction reaction using an oxidizing agent and a reducing agent; A second pretreatment step in which primary pretreated water pretreated in the first pretreatment step is introduced into a second oxidation-reduction section to further decompose organic matter and inorganic salts of the primary pretreated water through a secondary oxidation-reduction reaction, and radical water is sprayed in a softening section to remove hardness components; and A main treatment step comprising receiving the secondary pretreated water pretreated in the second pretreatment step and continuously performing reverse electrodialysis and bipolar electrodialysis to perform desalination treatment of the secondary pretreated water in a non-evaporative manner; The above first and second oxidation-reduction units are, A method characterized by performing an oxidation-reduction step in which an oxidation reaction by the oxidizing agent and a reduction reaction by the reducing agent proceed simultaneously.

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