Brine purification device, its purification method and uses thereof

Abstract

The present disclosure relates to a brine purification device, its purification method and uses thereof. It is disclosed a brine purification device comprising a housing with an inlet configured to receive untreated brine and an outlet configured to discharge purified brine from a purification chamber; wherein the purification chamber within said housing is configured to have two separated hemispheres; wherein the at least one plate comprises a first engraved serpentine flow channel in a first side configured for the flowing of brine and a second engraved serpentine flow channel in the opposite side of the same plate configured for the flowing of a flowing fluid; wherein the two sides of the at least one plate are separated by an anion-exchange membrane in such a way that the untreated brine combine with counter-ions from the flowing fluid through said anion-exchange membrane; wherein the at least one plate is configured for a fluid velocity of 0.007 to 0.015 m / s considering a thickness of 3 to 6 mm.

Description

D E S C R I P T I O NBRINE PURIFICATION DEVICE, ITS PURIFICATION METHOD AND USES THEREOFTECH NICAL FIELD

[0001] The present disclosure relates to a brine purification device, its purification method and uses thereof.BACKGROUND

[0002] Attending to the current water scarcity scenario, which is being stressed by the increasing socioeconomic growth, it is imperative to develop and implement solutions to circumvent the worldwide deficit. Nowadays, nearly 1 / 5 of the world's population faces freshwater scarcity, with UNESCO (Paris 2015) foreseeing that by 2030, this value will increase to ca. 40 %. Attending to the fact that 97% of the entire water supply is seawater, it is inevitable and urgent the transition to desalinated water to serve domestic and industrial applications.

[0003] Reverse osmosis is a technique that shows promise in this respect for eliminating salts from seawater and producing freshwater, as product stream, that is suitable for drinking. Undoubtedly, among the current generation of desalination technologies, the latter has garnered more attention globally and has expedited its deployment to a total of 65% worldwide. By the end of 2017, 19 372 desalination plants were operating in different parts of the world, with a combined daily capacity of around 99.8 million m3. Although desalination via reverse osmosis generates freshwater, this technique has a low efficiency of < 45 %. Therefore, huge amounts of brine, the by-product are produced worldwide. This stream created during the process poses a serious environmental risk. Typically, high-salinity brines from seawater reverse osmosis (SWRO) are frequently disposed of in the environment, including land application, deep-well injection, surface water / ocean discharge, sewer discharge, and evaporation ponds. Beyond its high salt content, brine can also harbor harmful organic substances, heavy metals, and processing chemicals. The adverse consequences ofbrine disposal on soil health, groundwater resources, and marine ecosystems have been extensively examined by scientists. As a result, eutrophication, pH alterations, an increase in heavy metal concentrations in marine ecosystems, and other issues are examples of potential environmental damage.

[0004] In particular, the magnesium complex, Mg(OH)2 is particularly interesting to being recovered. However, the conventional industrial production of magnesium from seawater involves the reaction between Mg2+ions in seawater and hydroxide (OH ) ions from chemicals like calcium hydroxide (CafOH ) or sodium / potassium hydroxide (NaOH, KOH) to produce magnesium hydroxide (MgfOH ). Similarly, in some zero liquid discharge (ZLD) processes, the recovery of magnesium is achieved at the downstream of the process by concentrating the seawater using electrodialysis (ED) and then generating Mg(OH)2 magnesium compound through the addition of precipitants.

[0005] However, these conventional methods require complicated pretreatment processes and the use of high concentrations of chemicals to obtain high-purity magnesium hydroxide. But most importantly, the magnesium recovery is typically carried out in a batch mode, which is space-intensive, high-cost, and therefore not so profitable. Also, the addition of precipitant solutions dilutes the waste stream, making it more difficult and energy-intensive to evaporate the water and concentrate the solids in the later stages of the ZLD process. This increased energy demand leads to higher operating costs for the overall ZLD system.

[0006] More recently, a novel method for producing Mg(OH)z and Ca(OH)2 has been reported involving electrodialysis (ED). This new method claims to be the up to date sole method for producing Mg(OH)2 via a continuous and mineral selective technique. The authors claim the development of a water electrolysis system for continuous magnesium recovery, wherein the main approach considered that in the water electrolysis process, H+ions are generated at the anode, while OH- ions are generated at the cathode. Additionally, positive ions like Na+are transported from the anode to the cathode solution through a cation exchange membrane.

[0007] The current density is set to avoid water dissociation on the cation exchange membrane, preventing the neutralization of H+and OH- ions. As a result, the pH increases in the cathode solution while decreasing in the anode solution.

[0008] The OH- ions generated at the cathode are utilized to form magnesium hydroxide (MgfOH ), as its solubility (1.8 x 1011mol / L) is much lower than that of calcium hydroxide (Ca(OH)2, 5.5 x 10’6mol / L).

[0009] However, the OH’ ions may also react with other ions in seawater, particularly forming insoluble calcium carbonate (CaCOs) due to the high abundance of bicarbonate ions (HCO3) in the deep-ocean water and the increasing pH in the cathode solution. It was then found that the formation of magnesium hydroxide was directly related to the electricity input during water electrolysis, influencing the production of OH’ ions. Calcium hydroxide production was attained after the depletion of Mg2+ions, while calcium carbonate formed initially due to the reaction of Ca2+ions and carbonate ions from increased pH. They added a deaeration step for enhanced magnesium hydroxide purity and which preventing calcium carbonate formation, resulting in a 99% pure magnesium hydroxide compound. The proposed method demonstrated a theoretical cost of 0.97 USD per kg of magnesium hydroxide, showcasing costeffectiveness compared to conventional methods. However, this has not been patented nor it is a commercial technique, moreover the application considered ultra highly concentrated brines with undesirable high HCO3’ concentrations.

[0010] In document KR20130073500A, it is described a producing method of seawater magnesia using concentrated seawater to produce seawater magnesia with high productivity and simple processes by using a solid-liquid separator and the concentrated seawater obtained from a seawater desalination process. In the document, a producing method of seawater magnesia using concentrated seawater comprises the following steps: decarbonating the concentrated seawater obtained from a seawater desalination process; precipitating magnesium hydroxide by adding a precipitation agent to supernatant of the decarbonated concentrated seawater; separating and filtering magnesium hydroxide from the supernatant using a solid-liquid separator; and plasticizing the separated magnesium hydroxide. The seawater desalination process is a reverse osmotic pressure type seawater desalination process.The precipitation agent is one or more selected from Ca (OH or NaOH. The producing method of seawater magnesia processes the supernatant without magnesium hydroxide with a nanofilter into concentrated water and processed water.

[0011] Document CN102795719A describes methods for removing calcium and magnesium and co-producing water and salt by a low-cost process during sea water desalination. By the methods, on the basis of removing the calcium and magnesium in the sea water desalination industry, water and salt producing processes can be integrated, so that fresh water can be produced when the crude salt is produced; sea water is treated by a low-cost method for removing calcium and magnesium ions, so that the sea water cannot be scaled, and the sea water desalination and vacuum salt production are linked; the sea water is refined by a lime-mirabilite-carbon dioxide method, and the used raw materials are lime, mirabilite and carbon dioxide which are cheap and readily available; the process comprises the following steps of removing magnesium, namely adding a proper amount of mirabilite into the sea water, adding lime milk, and reacting the magnesium ions to form magnesium hydroxide precipitations so as to remove the magnesium; causticizing, namely causticizing superfluous calcium hydroxide and sodium sulfate to form calcium hydroxide and sodium sulfate precipitations, and separating the produced sodium sulfate precipitation; removing calcium, namely introducing flue gas into concentrated sea water subjected to magnesium removal and causticizing, reacting the calcium hydroxide and the carbon dioxide to form sodium carbonate, reacting the sodium carbonate and the calcium ions to form calcium carbonate so as to remove calcium.

[0012] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.GENERAL DESCRIPTION

[0013] The present disclosure relates to a brine purification device, its purification method and uses thereof.

[0014] The now disclosed fully automatized, plug-and-play brine purification device simplifies installation, minimizing costs and enabling completely continuous operation.In an embodiment, the device is equipped with loT devices intertwined with remote control; thus, any unexpected shutdown or deviation on the brine stream parameters can be handled, ensuring consistent and reliable performance across diverse operating conditions.

[0015] The developed brine purification method occurs at ambient pressure and room temperature. Normally, the resulting brine from desalination via reverse osmosis, i.e. through the prior art method, has a pH of up to 8.5 and conductivity within the range between 30000 ppm and 100000 ppm. This brine stream includes mostly substantial amounts of MgC , CaC , and NaCI, among other minor components, namely sulphates and bicarbonates with lOx lower concentration. However, these minor components shall be removed as well to guarantee the highest purity of both water and crystallized NaCI.

[0016] From other perspective, in the brine purification method now disclosed, brine is admitted to a brine purification device now developed. The selective removal of minerals from brine in the form of Mg(OH)2 involves a pH adjustment up to a range of 9.5 to 11 through the use of NaOH at optimal concentration and flowrate, without applying additional sources of energy, such as electricity to drive the reaction by applying external voltages. As fed brine is highly concentrated in MgC (1.6 g / L to 7.6 g / L) Mg2+ions can combine with OH- counter-ions that are transferred through a polymeric anion-exchange membrane which enables rapidly the seeding of Mg(OH)2 crystals. The device design avoids the direct mixing of the two solutions with the use of the highly selective polymeric anion-exchange membrane that separates the compartments of inlet brine saline solution and inlet reactant with alkaline solution. The OH- ion exchange is governed by a driving force promoted by the concentration gradient across the membrane. Magnesium hydroxide has a very low solubility (5.61 x 10“12at 25°C), therefore the saturation point is reached very quickly, with a residence time of less than 5 seconds, hindering the co-precipitation of other hydroxides, namely CaCOs. Moreover, NaOH is continuously recirculated during the entire recovery process, which incredibly lowers the operational costs of the process. The initial stage of the multistage recovery process allows the continuous production of Mg(OH)2.

[0017] Upon Mg(OH)2 precipitation, in a buffer tank the resulting brine stream is subjected to a solid-liquid separation for recovering solid MgfOH particles with purity over 90 %, and a resultant liquid stream denominated as "purified brine" is again admitted to the membrane-based device, to recover CafOH in the second stage of the process. In this case, the precipitation condition is altered, and the pH should be increased up to pH 11.5. Solid CafOH is recovered with high purity after being subjected to a solid-liquid separation.

[0018] The brine stream free of Mg2+and Ca2+and rich in NaCI can then be treated to recover the water. The evaporation of the NaCI-rich stream will produce crystalline NaCI with high quality grade, which followed by vapor condensation enables a significant increase in the production of purified water, doubling the performance of seawater desalination processes. The device now disclosed recovers from 90% to 98%. The absence of Mg2+and Ca2+in the recovered water also guarantees no need for added chemicals to neutralize any residual alkalinity.

[0019] It is considered along this description that ambient pressure on an object is the pressure of the surrounding medium, such as a gas or liquid, in contact with the object. The SI unit of pressure is the pascal (Pa), which is a very small unit relative to atmospheric pressure on Earth, so kilopascals (kPa) are more commonly used in this context. The ambient atmospheric pressure at sea level is not constant: it varies with the weather, but averages around 100 kPa.

[0020] It is also considered along this description that room temperature is the air temperature of any object or environment where equipment is stored. The adjective ambient means "relating to the immediate surroundings." This value is also referred to as the ordinary temperature or the baseline temperature. Temperature ranges are defined as room temperature for certain products and processes in industry, science, standards, and consumer goods. For instance, for the shipping and storage of pharmaceuticals, the United States Pharmacopeia-National Formulary (USP-NF) defines controlled room temperature as between 20°C and 25°C, with excursions between 15°C and 30°C allowed, provided the mean kinetic temperature does not exceed 25°C. The European Pharmacopoeia defines it as being simply 15°C to 25°C, and the Japanese Pharmacopeia defines "ordinary temperature" as 15°C to 25°C, withroom temperature being 1°C to 30 °C. Merriam-Webster gives as a medical definition a range of 15°C to 25°C as being suitable for human occupancy, and at which laboratory experiments are usually performed.

[0021] An aspect of the disclosure comprises a brine purification device comprising a housing with an inlet configured to receive untreated brine and an outlet configured to discharge purified brine from a purification chamber; wherein the purification chamber within said housing is configured to have two separated hemispheres; wherein the at least one plate comprises a first engraved serpentine flow channel in a first side configured for the flowing of brine and a second engraved serpentine flow channel in the opposite side of the same plate configured for the flowing of a flowing fluid; wherein the two sides of the at least one plate are separated by an anion- exchange membrane in such a way that the untreated brine combine with counterions from the flowing fluid through said anion-exchange membrane; wherein the at least one plate is configured for a fluid velocity of 0.007 to 0.015 m / s considering a thickness of 3 to 6 mm.

[0022] In an embodiment, the at least one plate of the brine purification device comprises the absence of void volumes.

[0023] In an embodiment, the at least one plate of the brine purification device comprises a channel with a section ranging from 14 cm2to 60 cm2, preferably from 20 cm2to 50 cm2, more preferably from 25 cm2to 45 cm2.

[0024] In an embodiment, the at least one plate of the brine purification device comprises a channel in the form of a tube with a diameter from 1 cm - 3 cm.

[0025] In an embodiment, the purification chamber of the brine purification device further comprises a drum filter with a maximum pore size of up to 5 pm, preferably from 0.1 pm to 5 pm, more preferably from 0.2 pm to 4.5 pm.

[0026] In an embodiment, the drum filter of the brine purification device is partially submerged in a tank continuously fed with untreated brine and a vacuum pressure ranging from 10 to 30 kPa inside said drum filter.

[0027] In an embodiment, the anion-exchange membrane of the brine purification device comprises a material selected from a list consisting of polypropylene, styreneethylene, polystyrene, styrene and vinyl benzyl chloride or their combinations thereof.

[0028] In an embodiment, the at least one plate of the brine purification device is made of a material selected from a list consisting of aluminum, polypropylene, polyether ether ketone, polyvinyl chloride, or their combinations thereof.

[0029] In an embodiment, the brine purification device further comprises a polymeric gasket.

[0030] In an embodiment, the polymeric gasket of the brine purification device is selected from a list consisting of an ethylene propylene diene monomer, polytetrafluorethylene, glass fiber, or their combinations thereof.

[0031] In an embodiment, the flowing fluid circulating in the engraved serpentine flow channel of the brine purification device is selected from a list consisting of NaOH, Ca(OH)2, or their combinations thereof.

[0032] In an embodiment, the thickness of the at least one plate of the brine purification device is from 2 mm to 10 mm, preferably from 3 mm to 6 mm.

[0033] In an embodiment, the brine purification device further comprises a control unit configured to monitor and adjust the flow rate and filtration stages.

[0034] In an embodiment, the control unit of the brine purification device includes sensors for detecting the concentration of specific contaminants and adjusting the operation of the filtration units and chemical treatment module.

[0035] In an embodiment, the control unit of the brine purification device is programmable and can be connected to a remote monitoring system for real-time data analysis and operational adjustments.

[0036] In an embodiment, the inlet and outlet of the brine purification device are equipped with flow control valves to regulate the flow of brine through said device.

[0037] In an embodiment, the filter material in each filtration unit of the brine purification device is replaceable and can be selected based on the specific contaminants present in the untreated brine.

[0038] In an embodiment, the brine purification device further comprises a UV sterilization unit located downstream of the purification chamber to eliminate microbial contaminants from the brine.

[0039] In an embodiment, the brine purification device comprises a plurality of plates.

[0040] In an embodiment, the brine purification device comprises at least two or three or four or five or six or seven or eight or nine or ten plates.

[0041] It is also disclosed the use of the brine purification device for recovery of Mg(OH)2and Ca(OH)2.

[0042] It is also disclosed a method for brine purification using the described brine purification device, comprising the following steps: admit the brine to the water purification device, where said brine is passed through the engraved serpentine flow channel of the plate; admit a flowing fluid to flow in a second engraved serpentine flow channel in the opposite side of the same plate; the anion-exchange membrane allow the combination of the untreated brine with counter-ions from the flowing fluid; the resulting brine stream from the previous step is subject to a solid-liquid separation at a pre-determined pH level; the resulting brine stream from the previous step is passed through the brine purification device with different pH level in comparison of the pH level of the first step.

[0043] In an embodiment, the pre-determined pH level on the step of the resulting brine stream being subject to a solid-liquid separation at a pre-determined pH level on the described method is based on the range of up to 11.

[0044] In an embodiment, the pre-determined pH level on the step of the resulting brine stream in the described method is in the range from 9 to 11, preferably from 10 to 10.5.BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of invention.

[0046] Figure 1: Schematic representation of an embodiment of a multistage brine purification procedure according to the brine purification method now disclosed.

[0047] Figure 2: Schematic representation of an embodiment of the brine purification method now disclosed.

[0048] Figure 3: Schematic representation of the cleaning / purging water system of the brine purification device.

[0049] Figure 4: Schematic representation of an embodiment of the brine purification device, with a compact and exploded views.

[0050] Figure 5: Schematic representation of an embodiment of the plates of the brine purification device.

[0051] Figure 6: Illustration of the velocity profile on an embodiment of the plates of the brine purification device.DETAILED DESCRIPTION

[0052] The present disclosure relates to a brine purification device, its purification method and uses thereof.

[0053] In an embodiment, illustrated in Figure 4, the newly engineered brine purification device comprises at least one plate specifically designed to receive the brine to be treated, which is separated from NaOH plates by employing an anionselective exchange membranes. The innovative NaOH two-sided plates can participate simultaneously in the recovery of MgfOH and CafOH by using the opposite sides of the same plate, since each plate for NaOH circulation is engraved with a serpentine flow field on both ends.

[0054] In an embodiment, each cell of the brine purification device comprises at least one plate dedicated to MgfOH recovery, another to CafOH production which receives "purified brine", and a plate of NaOH in the middle working simultaneously for both sides of said device. NaOH flow paths are separated from brine and "purified brine" by employing the membranes. Thus, flow paths for Mg(OH)2 and CafOH recovery, meaning the admission of brine and "purified brine", are entirelyindependent to eliminate any possibility of contamination guaranteeing continuous operation. In fact, if any fault is identified in the production cycle of Ca(OH)2, the continuous production of Mg(0H)2 is not directly affected and vice-versa.

[0055] In an embodiment, the process requires the use of several cells stacked in series which facilitates the scale-up of the technology. The capacity of the brine treatment device is therefore determined by the number of membranes and their active area.

[0056] In an embodiment, the stack was developed to enable an optimized distribution of flow, which is equally distributed through the different assembled plates engraved with improved serpentine-shaped channels. The flow field geometry and pattern were derived to ensure the optimal reactant flow attending to the velocity of the fluid, variation of volumetric flow rate per compartment: brine / "purified brine" vs NaOH sides, and the consequent pressure distribution of fluid in operation before and after the reaction. A good flow distribution is essential to significantly reduce the risk of fouling, leading to a more efficient, reliable, and cost-effective operation. In detail, an uneven flow distribution would cause pressure variations and the presence of stagnant zones. Particles suspended in the fluid may accumulate in these sluggish zones, and over time, these deposits can restrict the flow path, reducing efficiency and causing operational problems. Also, the thickness of each plate for fluid distribution, which in turn can influence the volume of fluid that can be effectively treated, was optimized to increase the efficiency of the treatment process. For example, thicker flow channels can create a narrower fluid distribution. This can decrease the residence time, meaning the amount of time a fluid element spends within the treatment zone in contact with the membrane, which is a source of reactant for formation of MgfOH and Ca(OH)2. If the residence time is too low due to thicker flow channels and higher flow rates, then the process is not-so-efficient. In this device, it is utterly relevant to ensure a high surface area-to-volume ratio and promote efficient mixing while minimizing the time required to treat a specific volume of fluid. Thus, advanced computer simulations were used to analyze the flow patterns throughout the improved reactor plates as can be illustrated in Figure 5, which reveals the absence of void volumes, and an optimal fluid velocity of 0.007 - 0.015 m / s considering athickness of the flow plates of 3 mm. In an embodiment, the manufacturing material of the plate is polypropylene (PR).

[0057] In an embodiment, the end plates play a vital role in ensuring the structural support of the brine purification device by compressing the other internal components, maintaining pressure integrity, and facilitating uniform fluid distribution. These plates were designed and manufactured using corrosion-resistant yet light aluminium material, compatible with harsh chemical environments, which is critical to ensure the durability of the brine purification device. Besides, to prevent fluid leaks, the cell was designed with 10 bolts used to tighten the system with 8 Nm of torque and employing EPDM gaskets with 300 pm of thickness between the flow plates (admission plate, brine plate, etc) and the membrane.

[0058] All procedures are controlled by a set of valves able to actuate automatically according to the pre-defined operating conditions, as illustrated in Figure 2. Brine initially admitted from the reverse osmosis outlet enters a brine buffer tank where it is kept reserved (1); then the brine stream is pumped (2), directly towards the stack (9), passing through a variety of actuators / valves and sensors that allow monitoring flow rate, pressure, temperature, pH among others, and governing the flow stream whenever any of the intended parameters are not correct (3, 4, 5, 6, 7, 8). Simultaneously, NaOH solution passes through the stack (9), on the opposite side of the membrane in each cell, from a NaOH reservoir (10). In detail, the system has autonomous NaOH dispensers (10 and 17) designed to maintain optimal working conditions which are required for treating brine and "purified brine" streams (80). The dosing system is equipped with a set of pumps (11 and 18) that continuously dose a certain amount of alkaline solution according to the data collected in real-time by pH sensors placed in the buffer tanks of NaOH. Furthermore, in an embodiment, after passing the brine purification device, the NaOH pipework is equipped with conductivity sensors to double-check operational conditions over time.

[0059] During the procedures, if the proper pH conditions are not reached in the brine and / or "purified brine" streams (7 and 85), then, a recirculation process is activated for readmission of the brine and / or "purified brine" (16 and 79), to the brine purification device to maintain high production rates. At this moment, the admission of new brineor "purified brine" is ended, but the NaOH stream continues flowing simultaneously with the recirculation of brine or "purified brine". This procedure is governed independently, therefore, a recirculation step on the brine side does not imply a recirculation step on the "purified brine" side of the process. In an embodiment, when the pre-set pH is achieved then the brine recirculation loop is interrupted, and the system starts working normally, with new brine entering flowing again. Normally, recirculation of brine takes no longer than 10s until reaching the desired pH and is mainly unlocked when there are slightly different concentrations at the brine inlet.

[0060] In an embodiment, after flowing through the brine purification device, the brine and "purified brine" (20 and 82) streams with solids suspended are separately subjected to a solid-liquid separation using a drum filter which is a suitable method for high-volume applications. In this brine purification device, a cylindrical drum is partially submerged in a tank being continuously fed with the liquid-solid mixture, and a vacuum of from 10 to 30 kPa, preferably from 12 to 25 kPa, more preferably from 15 to 22 kPa, absolute pressure is applied to the inside of the drum. As it rotates, the liquid portion of the mixture passes freely through the mesh screen and solids larger than the mesh size are left behind on the outer surface of the drum. This creates a filter cake, a layer of accumulated solids that are continuously collected. The mesh size can be chosen depending on the desired particle size separation. In this case, to ensure high efficiency, the maximum pore size is up to 5 pm, preferably from 0.1 to 5 pm, more preferably from 0.2 to 4.5 pm, and the fabric material shall withstand pH from 10 to 15, preferably from 10 to 13, more preferably from 11 to 12.

[0061] In an embodiment, the entire operation is ready to circumvent any faulty event and bring the operation to a batch mode system temporarily to ensure the longest lifetime period of all apparatus and balance of plant equipment, as illustrated in figure 3. For instance, if production at the brine purification device, of Mg(OH)2 or Ca(OH)2 or treatment capacity ensued by the membranes declines, detected by visualization of stable pH at lower set-points than expected, and / or pressure variations are detected while the device is in operation, a safety protocol is activated. In an embodiment, a flash purge of water circulating through the device is triggered to restore ideal conditions and eliminate any possible product that might be accumulated (75 and 76).The cleaning process is set for a specific period until ideal conditions are again detected; typically, no longer than 30 seconds. During this procedure, the admission of fresh brine and circulation of NaOH to the device is temporarily halted (2, 11). At the same time, if no variations were identified in the Ca(OH)2 recovery part of the system, then its production is not affected and the respective part of the system should work continuously, and vice-versa (10, 11, 12, 13, 14, 15). This is made possible due to the fact the device and balance of the plant are designed to have two independent hemispheres, as above mentioned. After the cleaning, a buffer tank is then refilled automatically with clean water (75). The purge stream can be drained to an external waste collection system (25). This stream corresponds to up to 5 % of the treated brine or "purified brine" volume and normally presents a low level of conductivity, i.e. below 500 uS / cm.

[0062] In an embodiment, the anion-exchange membranes should be activated overnight in IM KOH solution before being used as a solid polymeric electrolyte to separate both plates. The reactants - brine or "purified brine": NaOH, should be fed continuously to the system under a specific flow rate ratio. According to the results presented in Table 1, to ensure a strong Mg(OH purity of 98 wt.%, NaOH should be admitted with a concentration of 0.75 M under a flow rate ratio of 1:2 (V / V) - step 2. Despite NaOH being fed to the system at a higher concentration, the maximum consumption registered of NaOH is 0.16 M per liter of treated brine. For recovering Ca(OH)2, the concentration of NaOH should be increased up to 2 M at 1:4 (V / V) flow ratio, but the consumption rate is not higher than 0.04 M per liter of brine - step 5. In Table 1, values > 100 % from ICP reveal the co-precipitation of Mg(OH and Ca(OH)2.

[0063] Table 1 - Mg and Ca percentage in MgfOH and CafOH samples from IPC-OES after applying different operating conditions.ICP-OES / ICP-OES / Active Flow rate Flow rateNaOH wt.% wt.%Area ratio ratio(M) Mg from Ca from cm2Step 2 Step 5Mg(OH)2Ca(OH)21:1 1:1 13 50.5 12 1:2 1:2 60 151:4 1:4 76 241:1 1:1 19 140.75 12 1:2 1:2 98 451:4 1:4 105 671:1 1:1 27 182 12 1:2 1:2 112 731:4 1:4 125 91

[0064] Table 2 displays the relation between yield versus brine flow admitted to the system. Low flow rates cause insufficient distribution of reactants, resulting in decreased solids production. When the flow is too strong, the time for ionic exchanges inside the reactor is too short. Thus, considering a system with 3 membranes of 12 cm2active area, the removal efficiency of magnesium salts from a brine stream of 5 L min1reaches the maximum yield of 100 % with a high percentage of > 90 % of Mg in Mg(OH)2 samples, according to ICP results. The calcium hydroxide precipitation step enabled a remarkable efficiency of 94% CafOH recovery.

[0065] Table 2 - Results of yield versus flow of brine admitted to the multistage reactor.Active N5Flow rate ratio BrineNaOH YieldArea Membranes flow(brine:NaOH (M) % cm'2solution) L min153 2Step 2 o.75 12 3 1:2 100 575 1039 2Step 5 2 12 3 1:4 94 521 10

[0066] The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0067] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above-described embodiments are combinable.

[0068] The following dependent claims further set out particular embodiments of the disclosure.

Claims

C L A I M S1. A brine purification device comprising: a housing with an inlet configured to receive untreated brine and an outlet configured to discharge purified brine from a purification chamber; wherein the purification chamber within said housing is configured to have two separated hemispheres; wherein the at least one plate comprises a first engraved serpentine flow channel in a first side configured for the flowing of brine and a second engraved serpentine flow channel in the opposite side of the same plate configured for the flowing of a flowing fluid; wherein the two sides of the at least one plate are separated by an anion- exchange membrane in such a way that the untreated brine combine with counter-ions from the flowing fluid through said anion-exchange membrane; wherein the at least one plate is configured for a fluid velocity of 0.007 to 0.015 m / s considering a thickness of 3 to 6 mm.

2. The brine purification device according to the previous claim, wherein the at least one plate comprises the absence of void volumes.

3. The brine purification device according to any of the previous claims, wherein the at least one plate comprises a channel with a section ranging from 14 cm2to 60 cm2, preferably from 20 cm2to 50 cm2, more preferably from 25 cm2to 45 cm2.

4. The brine purification device according to any of the previous claims, wherein the at least one plate comprises a channel in the form of a tube with a diameter from 1 cm - 3 cm.

5. The brine purification device according to any of the previous claims, wherein the purification chamber further comprises a drum filter with a maximum pore size ofup to 5 pm, preferably from 0.1 pm to 5 pm, more preferably from 0.2 pm to 4.5 pm.

6. The brine purification device according to the previous claim, wherein the drum filter is partially submerged in a tank continuously fed with untreated brine and a vacuum pressure ranging from 10 to 30 kPa inside said drum filter.

7. The brine purification device according to any of the previous claims, wherein the anion-exchange membrane comprises a material selected from a list consisting of polypropylene, styrene-ethylene, polystyrene, styrene and vinyl benzyl chloride or their combinations thereof.

8. The brine purification device according to any of the previous claims, wherein the at least one plate is made of a material selected from a list consisting of aluminum, polypropylene, polyether ether ketone, polyvinyl chloride, or their combinations thereof.

9. The brine purification device according to any of the previous claims, further comprising a polymeric gasket.

10. The brine purification device according to any of the previous claim, wherein the polymeric gasket is selected from a list consisting of an ethylene propylene diene monomer, polytetrafluorethylene, glass fiber, or their combinations thereof.

11. The brine purification device according to any of the previous claims, wherein the flowing fluid circulating in the engraved serpentine flow channel is selected from a list consisting of NaOH, Ca(OH)2, or their combinations thereof.

12. The brine purification device according to any of the previous claims, wherein the thickness of the at least one plate is from 2 mm to 10 mm, preferably from 3 mm to 6 mm.

13. The brine purification device according to any of the previous claims, further comprising a control unit configured to monitor and adjust the flow rate and filtration stages.

14. The brine purification device according to the previous claim, wherein the control unit includes sensors for detecting the concentration of specific contaminants and adjusting the operation of the filtration units and chemical treatment module.

15. The brine purification device according to the previous claims 13 to 14, wherein the control unit is programmable and can be connected to a remote monitoring system for real-time data analysis and operational adjustments.

16. The brine purification device according to the previous claims, wherein the inlet and outlet are equipped with flow control valves to regulate the flow of brine through said device.

17. The brine purification device according to the previous claims, wherein the filter material in each filtration unit is replaceable and can be selected based on the specific contaminants present in the untreated brine.

18. The brine purification device according to any of the previous claims, further comprising a UV sterilization unit located downstream of the purification chamber to eliminate microbial contaminants from the brine.

19. The brine purification device according to any of the previous claims, comprising a plurality of plates.

20. The brine purification device according to any of the previous claims, comprising two or three or four or five or six or seven or eight or nine or ten plates.

21. The use of the brine purification device for recovery of MgfOH and Ca(OH)2.

22. A method for brine purification using the brine purification device described in any of the claims 1 to 20, comprising the following steps: admit the brine to the water purification device, where said brine is passed through the engraved serpentine flow channel of the plate; admit a flowing fluid to flow in a second engraved serpentine flow channel in the opposite side of the same plate; the anion-exchange membrane allow the combination of the untreated brine with counter-ions from the flowing fluid; the resulting brine stream from the previous step is subject to a solid-liquid separation at a pre-determined pH level; the resulting brine stream from the previous step is passed through the brine purification device with different pH level in comparison of the pH level of the first step.

23. The method according to the previous claim, wherein the pre-determined pH level on the step of the resulting brine stream being subject to a solid-liquid separation at a pre-determined pH level is based on the range of up to 11.

24. The method according to any of the previous claims 22 to 23, wherein the predetermined pH level on the step of the resulting brine stream is in the range from 9 to 11, preferably from 10 to 10.5.

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