• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Reverse osmosis rejection water pretreatment equipment (1) for obtaining sodium hypochlorite, comprising means for removing sulfates with a first reagent, a first mixing device (5) and, first filtering means (6) ; water hardness removal means with at least one second and one third reagents, a second mixing device (9) and, second filter means (10); where the mixing devices (5, 9) are formed by a swirl mixer, and; a final storage tank (11). Water pretreatment process comprising the water input phases (21); removal of manganese and/or iron by adding oxygen (23); sulfate removal; elimination of the hardness of the reject water; neutralization of the pH (32) of the pretreated water and storage (33) of it in a final tank. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2759489A2
    申请号:ES201831052
    申请日:2018-10-30
    公开日:2020-05-11
    发明作者:Vives Ricardo Martinez；Anta Cristina Varona
    申请人:Usefulwastes Sl；
    IPC主号:
    专利说明:

    [0001]
    [0002] Reverse osmosis rejection water pretreatment equipment and pretreatment process using said equipment
    [0003]
    [0004] Technical field of the invention
    [0005]
    [0006] The present invention corresponds to the technical field of water purification processes by reverse osmosis, which generates a quantity of reject water with a high content of sulfates, calcium and magnesium, specifically, a pre-treatment equipment for said reject water for its use in obtaining sodium hypochlorite through an electrolysis reaction, as well as the process to obtain it using said equipment.
    [0007]
    [0008] Background of the Invention
    [0009]
    [0010] Reverse osmosis is a water purification technology by applying pressure to separate the solvent from a concentrated solution, by passing it through a semipermeable membrane. In this way the elimination of ions, molecules and larger particles in the water is achieved.
    [0011]
    [0012] By means of this reverse osmosis technology, it is possible to eliminate many types of elements suspended in water, including bacteria, and its application is currently widespread both in obtaining water suitable for use in industrial processes and in obtaining water. candy.
    [0013]
    [0014] Thus, reverse osmosis treatments have a well-known use aimed at obtaining higher quality water for domestic use in homes, and at the same time this reverse osmosis technology is being widely used in many other fields, given that the Rapid technological and industrial advancement has made it clear that natural water sources cannot meet the increasing fresh water demands of these fields.
    [0015]
    [0016] Initially, the desalination technique was used to eliminate the content of sea water salts. Later distillation appeared, with which pure water is obtained from contaminated water sources, as well as other processes such as ion exchange and electrodialysis.
    [0017] Currently, after the discovery of the reverse osmosis technique and its application to desalination of seawater and brackish water, it has been shown that it is the most economical and technically feasible technology, both for the desalination of water with content of salts such as for water purification with heavy metals, pesticides and other contaminants.
    [0018]
    [0019] The fields of application of osmosis technology are very varied, from obtaining drinking water to desalination of seawater and brackish water, production of ultrapure water, necessary for the electronic industry, wastewater treatment and industrial supplies. Among the latter are for example the food, pharmaceutical, medical, cosmetic, chemical, electronic, biotechnological industries, etc. where high quality water is required, including ultrapure water, with osmotic water being the basis for obtaining ultrapure water.
    [0020]
    [0021] However, reverse osmosis poses a fundamental drawback because the membranes that are used are characterized in that they perform continuous cleaning while they work, in order to avoid accumulation of contaminants and saturation of them in a short time. In this way, part of the inlet water is used to generate a carry-over of pollutants, salts and minerals and is called rejection water. The quantities depend on the equipment, but usually present a ratio of 50-40% of reject water for 50-60% of production.
    [0022]
    [0023] These rejection water values are very high, especially when it refers to the large quantities that are treated by reverse osmosis in sectors such as the industry.
    [0024]
    [0025] Thus, this high amount of rejection water obtained generates high costs in liters of water that are wasted, since they are directly transformed into rejection water and, in addition, these volumes of rejection water generate a storage and / or management problem to which it is necessary to look for a solution.
    [0026]
    [0027] Initially and until a control of these rejection waters was implemented, they were eliminated by dumping into the environment. However, since these reject waters are highly polluting, since the high content of salts they present can end life in the environment in which they are discharged, control standards and prohibitions were created for this type of discharge.
    [0028] From the appearance of these regulations that regulate the discharges of this type of rejects, the industries are forced to pay first of all for the acquisition of water that in a high percentage is directly transformed into rejection water and, at Secondly, to pay a waste collection and management company to take charge of these amounts of polluting water or, in the case of industries in which the water is mains water, eliminate it through the drain, paying to discharge it. dumping fee.
    [0029]
    [0030] There is another option for companies, which is to have tanks in which to store wastewater, but finally, in addition to the space they occupy, which not all companies have, it is still necessary for someone to take charge of the same.
    [0031]
    [0032] Given the high costs of all these options, for some companies it is not feasible to face them and they are forced to abandon their activity. In some cases, even a company has chosen to dodge the regulations and dump this waste into the environment despite the risks they pose to it, and risking heavy fines.
    [0033]
    [0034] It is therefore necessary to find a solution that allows the use of these reject waters so that the companies or industries that generate as many volumes of them can reuse them, giving them a new use and thus minimizing the losses that currently exist due to total waste. from the same. On the other hand, this would avoid the temptation of possible fraudulent discharges, because if a use is found for these reject waters, the volumes of discharges to be managed would be reduced, and therefore the costs involved.
    [0035]
    [0036] Since the rejection water is rich in sodium chloride, it would be possible to consider its use in the generation of lye by electrolysis and what would mean a use for these important volumes of rejection and at the same time, that the lye obtained could be used in the cleaning and disinfection tasks of industries, avoiding the purchase of this disinfection product.
    [0037]
    [0038] However, these rejection waters, in addition to sodium chloride, have high amounts of sulfate ions, as well as high levels of hardness, characteristics such which are not favorable for use in an electrolysis cell. Therefore, it would be necessary to find a process, as well as a team to carry it out, that would be able to adapt these rejection waters to the optimal conditions for use in an electrolysis cell, thus allowing their chemical transformation into bleach or sodium hypochlorite. . No process has been found in the state of the art that is capable of carrying out this transformation, nor has any equipment oriented to this end been found.
    [0039]
    [0040] As an example of the state of the art, reference documents ES2219223 and ES2328655 can be mentioned.
    [0041]
    [0042] Reference document ES2219223 defines a procedure for the electrolysis of saline waters containing sodium chloride with a parallel operation of amalgam electrolyzers and membrane electrolyzers with oxygen consumption cathode, with a common saline water circuit.
    [0043]
    [0044] This procedure has the phases of feeding the saline water from a salt dissolving station to a precipitation and filtration station, and gross separation of sulfate, calcium, and magnesium ions from the saline water in the precipitation and filtration station.
    [0045]
    [0046] Next, the division of the saline water into a main stream and a partial stream, electrolysis of the main saline water stream into an amalgam electrolyser is performed.
    [0047]
    [0048] Subsequently, the pre-treatment of the partial stream of saline water is carried out by removing free chlorine in a dechlorination station, precipitation, especially Al, Fe and Mg ions, in a hydroxide precipitation station, and separation of calcium and magnesium from saline water to a content of <20 ppb at the station, especially an ion exchanger.
    [0049]
    [0050] Subsequently, the electrolysis of the partial flow of saline water is carried out in a membrane electrolyzer with a mercury resistant oxygen consumption cathode, containing at least one silver catalyst, and pooling of the anolyte currents of the membrane electrolyzer and from the amalgam electrolyzer in a common anolyte stream.
    [0051] In this case, what is sought is the generation of chlorine from an undetermined source of saline water, purifying it first of all. And in the phases of the procedure prior to electrolysis, they carry out a precipitation of sulfate, calcium and magnesium ions by means of precipitation and filtration and by means of an ion exchanger, but the way in which it is carried out is not specified, the main object of this procedure being the phases of the electrolysis itself.
    [0052]
    [0053] In the memory of this document it is defined that the precipitation takes place in a common precipitation station in which all the ions are extracted, but this does not offer effective results, since mixing the reagents to generate the precipitation in it precipitation season, a complete precipitate is not allowed and the effectiveness is greatly reduced.
    [0054]
    [0055] Furthermore, the precipitate of all the mentioned ions, taken together does not allow obtaining suitable values for use in an electrolysis cell.
    [0056]
    [0057] It is a document that focuses on obtaining a procedure that allows amalgam electrolyzers and membrane electrolyzers to be used in parallel in a common saline water circuit, so it does not solve the problem that arises in this specification.
    [0058]
    [0059] Reference document ES2328655 defines a chemical-physical procedure for the purification of residual waters, in the manufacture of tartaric acid, from its salts, presenting: acidity, color, suspended solids, organic matter.
    [0060]
    [0061] This procedure presents a first phase of treatment of the residual water with quicklime and / or dilute calcium hydroxide up to a strong alkaline pH, favored with the elevation of the temperature, decanting salts and colloids.
    [0062]
    [0063] A second stage of adding a flocculant for the decantation and separation of solids. A third stage of neutralization with dilute acid, recommended hydrogen chloride. And finally, a fourth stage of treatment with sodium hypochlorite leaving the residual chlorine and dilution of the water.
    [0064]
    [0065] In this case the existence of precipitation of salts is determined, but not what are the salts that precipitate. Furthermore, with this process in which lime or calcium hydroxide is added, the precipitation of the sulfate ions is not achieved, at least not in its entirety.
    [0066] On the other hand, a flocculant is applied but the element to be eliminated with it is not specified. Given that it is a procedure aimed at wastewater with organic matter and suspended solids, it is logical to think that it is aimed at the elimination of these particles.
    [0067]
    [0068] In any case, it is a process that differs from what is required to solve the problem raised in this report, aimed at treating reverse osmosis rejection waters, which therefore do not have organic matter content or suspended solids.
    [0069]
    [0070] No procedure has been found in the state of the art whose objective is the preparation of the reverse osmosis rejection waters for a possible reuse thereof, for example in the production of sodium hypochlorite, nor has any equipment capable of carrying carry out this process.
    [0071]
    [0072] Description of the Invention
    [0073]
    [0074] The reverse osmosis rejection water pretreatment equipment, for use in obtaining sodium hypochlorite by means of an electrolysis reaction presented here, comprises sulfate removal means comprising a first and a second connected precipitate tank overflow. The first tank is connected to an inlet of the equipment through a first section of a water circulation circuit that has, connected to it according to the flow direction, oxygenation means, dosing means of a first reagent suitable for reacting with ions sulfate from the water and a first mixing device.
    [0075]
    [0076] The sulfate removal means further comprise first filtering means connected to the second tank through a second section having a first pump.
    [0077]
    [0078] The pretreatment equipment in turn comprises means for removing the water hardness that comprise a third and a fourth precipitate tank connected by overflow. The third tank is connected to the first filtering means by means of a third section of the circuit that is connected to it according to the direction of flow, dosing means of at least one second and one third reagents capable of reacting with calcium and magnesium and a second mixing device.
    [0079]
    [0080] These water hardness elimination means further comprise second filter means connected to the fourth tank through a fourth section that has a second pump.
    [0081]
    [0082] Both in the sulfate removal means and in the water hardness removal means, the first and second mixing devices are formed by a turbulence mixer, connected to the corresponding section in such a way that the water passes through it from a first to a second end thereof.
    [0083]
    [0084] The reject water pretreatment equipment also includes a final water storage tank, connected to the second filter media through a fifth section that has pH neutralization means.
    [0085]
    [0086] This memory proposes, in turn, a process of pretreatment of the reverse osmosis rejection water, by means of a pretreatment equipment as previously defined.
    [0087]
    [0088] Said pretreatment process presents the following phases.
    [0089]
    [0090] A first phase of the rejection water entering the equipment circuit.
    [0091]
    [0092] A second phase of removal of manganese and / or iron present in the reject water by adding oxygen with first oxygenation means.
    [0093]
    [0094] Then a third phase of sulfate removal takes place. This phase is carried out by means of steps consisting of adding a first reagent capable of reacting with sulfate ions in the water, mixing them with a first mixing device and a sulfate precipitate to the bottom of a first precipitate tank and of a second precipitate tank connected by overflow with the first.
    [0095]
    [0096] Next, the fourth phase is carried out consisting of removing the hardness of the reject water. This fourth phase is carried out by means of steps consisting of adding at least one second and a third reagents capable of reacting with the calcium and magnesium present therein, mixing in a second mixing device, and a precipitate of calcium and magnesium to the bottom of a third precipitate deposit and a fourth precipitate deposit connected by overflow with the third.
    [0097]
    [0098] Both in the third phase, after the precipitate step in the second precipitate tank, and in the fourth phase, after the precipitate step in the fourth precipitate tank, a phase of filtering the particles in suspension of water is carried out by first and second filter media respectively.
    [0099]
    [0100] Finally, a fifth phase of neutralization of the pH of the pretreated water takes place and its storage in a final tank.
    [0101]
    [0102] With the reverse osmosis rejection water pretreatment equipment, and the pretreatment process using said equipment proposed here, a significant improvement in the state of the art is obtained.
    [0103]
    [0104] This is so with this pre-treatment process and the pre-treatment equipment with which it is carried out, it is possible to adapt the characteristics of the reverse osmosis rejection water to those necessary so that the resulting water is suitable for treatment by electrolysis in an electrolytic cell, in order to obtain sodium hypochlorite.
    [0105]
    [0106] It is a process that presents a phase of elimination of sulfate ions in the first place by adding the reagent indicated for it in the flow of the rejection water itself within a circulation circuit. In this way, before reaching the precipitate tanks, the mixture is passed through a first mixing device by means of turbulence, which achieves a perfect mixing of the elements and great effectiveness in the subsequent precipitate when entering the precipitate tanks. .
    [0107]
    [0108] With the reduction of sulfate ions, a significant reduction of elements such as manganese is achieved at the same time.
    [0109]
    [0110] In the phase of eliminating the hardness of the water, the same procedure is applied, adding the necessary reagents in this case, but in the same way, in the flow of the reject water itself and with a passage through a turbulence mixer, which achieves great effectiveness in the subsequent precipitate.
    [0111] This process achieves an optimal reduction of sulfates and the hardness of the rejection water, resulting in suitable conditions for its use in obtaining sodium hypochlorite through an electrolysis process.
    [0112]
    [0113] The fact of being able to reuse this rejection water in the production of sodium hypochlorite or lye, is very favorable, since lye is a necessary product in the industries for disinfecting facilities, so that in addition to reducing the volumes of water from Rejection that should be managed, a necessary product is being generated for the company itself, so that it will be able to use the produced bleach reducing the costs of having to purchase it from third parties.
    [0114]
    [0115] On the other hand, the elements precipitated by this pretreatment process are collected through an outlet valve from the corresponding precipitate tanks and can be managed more easily, in a solid state and with a smaller volume.
    [0116]
    [0117] This process allows the possibility of subjecting a reverse osmosis treatment to the water obtained from the pre-treatment, so that after this new osmosis, a percentage that is suitable for consumption or the use to which it is obtained is obtained from the rejection water itself. direct in the industry and a rejection percentage that is lower than what had been obtained in the beginning and that also has no salt content, so it is not necessary to undergo pre-treatment again and can be directly directed to its use in obtaining sodium hypochlorite through electrolysis.
    [0118]
    [0119] In this way, in a company that treats with reverse osmosis a volume for example of 200m3, and obtains around 150m3 suitable for its use and around 50m3 of reject water, after applying the pre-treatment process eliminating the sulfates and the hardness of the water, and reapply a reverse osmosis, of the 50m3 of reject water, about 37.5m3 of the water can be recovered as suitable water, leaving only a volume of 12.5m3 to be used to obtain sodium hypochlorite.
    [0120]
    [0121] Therefore, it is a process with which a significant reduction of the volumes of rejection water is achieved and with the volumes that are obtained, it is possible to give them an alternative use such as the production of bleach.
    [0122]
    [0123] By taking advantage of the bleach produced, in the disinfection tasks of the companies themselves, costs of acquiring these disinfectant products are reduced. Equally, and even more relevant is the reduction in the costs of managing these reject waters, which, when reused, solves the problem of how to dispose of them, while the cakes resulting from precipitates are smaller in volume and easier to manage.
    [0124]
    [0125] On the other hand, the equipment for carrying out this pre-treatment is a compact equipment that can be contained in a structure that has sliding means such as lower wheels. This facilitates its easy location in the area considered optimal in the company and with the advantage that it occupies a fairly small volume.
    [0126]
    [0127] It is an equipment that presents a simple and reduced maintenance and that except in the first cycle in which the reagents are prepared with water from the network, in the rest of the cycles the pretreated water itself is used, therefore reducing costs even further of process.
    [0128]
    [0129] It is therefore a process that solves the problem of reverse osmosis rejection water management in a very efficient way, with low costs, and low maintenance, and by means of a simple, comfortable to use and low volume equipment.
    [0130]
    [0131] Brief description of the drawings
    [0132]
    [0133] In order to help a better understanding of the characteristics of the invention, according to a preferred example of its practical embodiment, a series of drawings is provided as an integral part of said description, where, by way of illustration and not limitation, represented the following:
    [0134]
    [0135] Figure 1.- Shows a plan view of the reverse osmosis rejection water pretreatment equipment, for a preferred embodiment of the invention.
    [0136]
    [0137] Figure 2.- Shows an elevation view of the reverse osmosis rejection water pretreatment equipment, for a preferred embodiment of the invention.
    [0138]
    [0139] Figure 3.- Shows a perspective view of the part of the pretreatment of the reverse osmosis rejection water, according to section A-A 'of Figure 1, for a preferred embodiment of the invention.
    [0140] Figure 4.- Shows a perspective view in the opposite direction to Figure 3, of the reverse osmosis rejection water pretreatment equipment, for a preferred embodiment of the invention.
    [0141]
    [0142] Figure 5.- Shows a schematic view of the equipment flow diagram, according to a preferred embodiment of the invention.
    [0143]
    [0144] Figure 6.- Shows a block diagram of the reverse osmosis rejection water pretreatment process, according to a preferred embodiment of the invention.
    [0145]
    [0146] Detailed description of a preferred embodiment of the invention
    [0147]
    [0148] In view of the figures provided, it can be seen how in a preferred embodiment of the invention, the reverse osmosis rejection water pre-treatment equipment (1), for use in obtaining sodium hypochlorite by means of a reaction of Electrolysis that is proposed here, comprises sulfate removal means, water hardness removal means and a final water storage tank (11).
    [0149]
    [0150] As shown in Figures 3, 4 and 5, the sulfate removal means comprise a first and a second overflow connected precipitate tank (2, 3), where the first tank (2) is connected to an equipment inlet (1) by means of a first section (T1) of a water circulation circuit.
    [0151]
    [0152] This first section (T1) of the circuit has connected to it according to the flow direction, a series of devices that are part of the means for removing sulfates and that are formed by means of oxygenation (4), means for dosing a first reagent capable of reacting with sulfate ions in water and a first mixing device (5).
    [0153]
    [0154] The sulfate removal means further comprise first filtering means (6) connected to the second tank (3) through a second section (T2) that has a first pump (B1).
    [0155]
    [0156] On the other hand, the means for eliminating water hardness are formed by a third and a fourth precipitate tank (7, 8) connected by overflow, where the third tank (7) is connected to the first filtering means (6) by means of a third section (T3) of the circuit.
    [0157]
    [0158] This third section (T3), as shown in Figures 3, 4 and 5, presents connected to it according to the flow direction, a series of devices that are part of the means of eliminating water hardness and are made up of a dosing means of at least one second and a third reagents capable of reacting with calcium and magnesium and a second mixing device (9) and, a second filter means (10) connected to the fourth tank (8) by means of a fourth section (T4) that has a second pump (B2).
    [0159]
    [0160] For its part, the final tank (11) of the pretreatment equipment is connected to the second filter media (10) by means of a fifth section (T5) that has pH neutralization media.
    [0161]
    [0162] Both the first mixing device (5) of the sulfate removal means and the second mixing device (9) of the water hardness removal means are formed by a turbulence mixer, connected to the corresponding section interleaved such that the water passes through it from a first to a second end of it.
    [0163]
    [0164] In this way, the first reagent that is added to the rejection water flow in the first section (T1) and said rejection water, are completely mixed before entering the first precipitate tank (2), and also occurs with the at least one second and third reagents and the rejection water before entering the third precipitate tank (7). Thus, when the mixtures enter the first or third precipitate tank (2, 7) respectively, they are already mixed and allowed to stand so that an optimal precipitate can be made from them.
    [0165]
    [0166] In this preferred embodiment of the invention, as shown in Figures 1, 2 and 5, the dosing means of a first reagent are formed by a containment tank (D1) thereof comprising stirring means and a device dispenser (12) of the first reagent in a section of the first section (T1) of the circuit. In this embodiment, the first reagent consists of a dilute barium hydroxide solution (Ba (OH) 2).
    [0167] Thus, as can be seen in Figure 5, the dosing means of at least one second and third reagents are formed by respective containment tanks (D2, D3) thereof, which comprise stirring means respectively and respective dosing devices ( 13, 14) of the second and third items in a section of the third section (T3)
    [0168]
    [0169] In this embodiment, said second and third reagents are formed respectively by a calcium hydroxide solution (Ca (OH) 2) and a sodium carbonate solution (Na2CO3).
    [0170]
    [0171] Both the first and the second and third reagents are in continuous movement in their respective containment tank (D1, D2, D3) so that the reagent remains in suspension, thanks to the means of agitation that they have.
    [0172]
    [0173] Likewise, in this preferred embodiment of the invention, the pretreatment equipment (1) comprises means for dosing a fourth reagent in a section of the third section (T3) prior to the second mixing device (9), formed by a containment tank (D4) of the fourth reagent and a dosing device (15) thereof, where the fourth reagent is formed by sodium hydroxide (NaOH).
    [0174]
    [0175] This fourth reagent is added in said third section (T3) of the circuit when the pH values of the rejection water are less than 12, since to achieve optimum precipitation it is necessary that the pH be greater than 12.
    [0176]
    [0177] As shown in Figure 5, in this preferred embodiment of the invention this equipment (1) comprises additional oxygenation means (16) of the water in a section of the third section (T3) prior to the second mixing device (9). In this case, both the oxygenation means (4) in the first section (T1) of the circuit and the additional oxygenation means (16) are formed by a blower, but in other embodiments they can be formed by an addition of chemicals, such as hydrogen peroxide or another with similar oxygenating characteristics.
    [0178]
    [0179] According to another aspect, in this preferred embodiment of the invention, the first and second filter means (6, 10) comprise a first filter (6.1, 10.1) and a second cartridge filter (6.2, 10.2) connected in parallel to the corresponding section, with control valves (VC) that allow the flow of the flow through the first or second filter.
    [0180] In this way, only one of the filters is in operation and when repair, replacement or maintenance tasks must be carried out on it, the corresponding control valves (VC) are closed and the other's control valves (VC) are opened. filter, so that the operation of the equipment is continuous and does not stop during these repair tasks.
    [0181]
    [0182] For its part, in this preferred embodiment of the invention, as shown in Figure 5, the pH neutralization means are formed by a containment tank (D5) of a pH neutralization reagent and a dosing device (17) of the same in a section of the fifth section (T5) of the circuit. In this embodiment, the neutralization reagent consists of 35% hydrochloric acid.
    [0183]
    [0184] In Figures 3 and 4 it is shown that in this preferred embodiment of the invention, the precipitate tanks (2, 3, 7, 8) comprise a valve for elimination (V1.1) of precipitated salts.
    [0185]
    [0186] On the other hand, the first and third precipitate tanks (2, 7) further comprise a valve for removing water residues (V1.2) and, the second and fourth precipitate tanks (3, 8) comprise a regulating valve (V2) of the flow outlet.
    [0187]
    [0188] In this preferred embodiment of the invention, the equipment (1) comprises an initial filtering device (18) arranged in the first section (T1) in a section thereof prior to the sulfate removal means connected thereto. With this device a coarse filtering of those elements of greater size that could carry the rejection water is carried out.
    [0189]
    [0190] As shown in Figures 3 and 4, in this preferred embodiment of the invention, the equipment (1) comprises flow regulation means at the circuit inlet formed by an inlet pump (B3) and two regulation valves. (V3). It also includes means for regulating the flow out of the circuit from the final storage tank (11), formed by an outlet pump (B4) and respective regulation valves (V4).
    [0191]
    [0192] This pretreatment equipment (1) also includes a series of taps (TM) for taking samples and some conductivity meters (C), arranged in certain sections of the circuit, respectively, for sample analysis.
    [0193] On the other hand, as can be seen in Figures 1 and 2, this equipment comprises a support structure (19) inside which all the elements thereof are arranged and where said support structure (19) comprises displacement means formed by wheels ( 20) lower.
    [0194]
    [0195] This allows a comfortable handling of the equipment (1) for its location in the most suitable place within the area of use of the same.
    [0196]
    [0197] In this report, a process of pretreatment of the reverse osmosis rejection water is also proposed, by means of a pretreatment equipment as previously defined.
    [0198]
    [0199] This process has the following phases, which are detailed below and shown in the diagram in Figure 6.
    [0200]
    [0201] A first phase of entry (21) of the reject water into the equipment circuit.
    [0202]
    [0203] The water enters the circuit through an inlet pump (B3) with respective regulation valves (V3) and in this preferred embodiment of the invention an initial filtering (22) is carried out therein by means of an initial filtering device ( 18).
    [0204]
    [0205] Subsequently, a second phase of removal of manganese and / or iron present in the reject water takes place by adding oxygen (23) with first oxygenation means (4).
    [0206]
    [0207] The third phase consists in the removal of sulfates by adding a first reagent (24) suitable for reacting with sulfate ions from the water, mixing them (25) with a first mixing device (5) and a sulfate precipitate (26) to the bottom of a first precipitate tank (2) and a second precipitate tank (3) connected by overflow with the first.
    [0208]
    [0209] After the precipitate in the second precipitate tank (3), a first pump (B1) drives the flow through a second section (T2) to the first filtering means, in which a filtering (27) of the particles in suspension from the water.
    [0210] In this embodiment, the first reagent is made up of dilute barium hydroxide and this solution is prepared in a containment tank (D1) of the same that includes stirring means and a dosing device (12) of this first reagent in a first section (T1) of the circuit.
    [0211]
    [0212] The reject water and this first reagent pass through the first mixing device (5) formed by a swirl mixer for further agitation. At this point of the circuit there is a tap (TM) for taking samples.
    [0213]
    [0214] The mixture is introduced into a first precipitate tank (2) so that the reaction between the first reagent and the sulfates takes place and the latter precipitate the bottom. When the first tank (2) is filled, the water goes overflow to the second precipitate tank (3) and if any element remains to be precipitated, it does so in this second tank (3).
    [0215]
    [0216] Since in this preferred embodiment of the invention the first reagent is made up of a dilute barium hydroxide solution, the removal of sulfates takes place as follows:
    [0217]
    [0218] 1- First, the dissociation of barium hydroxide occurs:
    [0219]
    [0220] Ba (OH) 2 ^ Ba 2+ 2OH "
    [0221]
    [0222] 2- Next, the barium combines with the sulfate ions present in the medium to form barium sulfate that precipitates:
    [0223]
    [0224] SOI + Ba 2 + ^ BaSO4 i
    [0225] 3- The OHs resulting from the equation start to precipitate part of the Magnesium present in the used flow:
    [0226]
    [0227] M g 2+ 2OH - ^ Mg ( OH ) 2 i
    [0228]
    [0229] Once these reactions have been carried out and the sulfates and part of the magnesium precipitate in the first and second precipitate tanks (2, 3), as already indicated, the first pump (B1) drives the flow to the first media filtering (6).
    [0230] Before entering these first filter media (6), the circuit includes a tap (TM) for taking samples.
    [0231]
    [0232] Once the quantity of sulfates required according to the specifications in the starting flow has been eliminated and a significant reduction in the content of other elements such as manganese has been achieved, the fourth phase of the process takes place, consisting of the elimination of the rejection water hardness and whose purpose is to completely eliminate the content of other elements, such as the aforementioned manganese and reduce the starting rejection water hardness by reducing the content of magnesium and calcium.
    [0233]
    [0234] This fourth phase is carried out by adding (28) at least one second and a third reagents capable of reacting with the calcium and magnesium present therein, mixing (29) in a second mixing device (9) and a calcium and magnesium precipitate (30) to the bottom of a third precipitate tank (7), and a fourth precipitate tank (8) connected by overflow with the third.
    [0235]
    [0236] Thus, at the exit of the first filter media (6), the addition of a second and third reagent takes place, which in this preferred embodiment of the invention are formed by a calcium hydroxide solution (lime milk, Ca (OH) 2) and a sodium carbonate solution (Na2CO3), respectively.
    [0237]
    [0238] To ensure correct mixing, once the reagents have been added, they are passed through a second mixing device (9) by means of turbulence.
    [0239]
    [0240] In this preferred embodiment of the invention, the phase of elimination of the hardness of the rejection water comprises a sampling (TM) prior to said addition (28) of the second and third reagents, in which the pH is measured to check which is correct.
    [0241]
    [0242] In this preferred embodiment of the invention, the process comprises an addition phase (34) of a fourth reagent, prior to mixing (29) in the second mixing device (9), to control the pH of the water, when the Sample analyzed in the sampling has a pH lower than 12 (TM1). If the pH is greater than 12 (TM2), the fourth reagent is not added.
    [0243] As shown in Figure 6, this process also comprises an additional phase of introducing oxygen (35) into the water, prior to mixing (29) in a second mixing device (9), by means of additional oxygenation means (16 ), when the sample analyzed in the sample collection shows manganese and / or iron (TM3) residues. If there are no residues (TM4), oxygenation is not performed
    [0244]
    [0245] Therefore, the process takes a sample at that point in the circuit and, depending on the presence of residues such as manganese or iron and the pH value, determines the need for the introduction of oxygen (35) and / or the addition of a fourth reagent. (29) to the water flow.
    [0246]
    [0247] Then, after mixing (29), there is another tap (TM) for sampling.
    [0248]
    [0249] The flow already mixed with the reagents after dosing passes to the third precipitate tank (7) where the precipitation begins and which has two valves, to remove salts (V1.1) and to remove water remains (V1. 2) after its precipitation. Once this third tank (7) of precipitate is carried, it overflows, pouring the contents into a fourth tank (8) of precipitate where there is also a valve to eliminate the possible remaining salts (V1.1) and another to regulate the flow (V2) outlet after all compounds have precipitated.
    [0250]
    [0251] The reactions that are carried out in these third and fourth precipitate deposits (7, 8), after the addition of the second and third reagents are as follows:
    [0252]
    [0253] CO2 Ca (OH) 2 - - CaCO3 i + H2O
    [0254] Ca (HCO3) 2 Ca (OH) 2 - 2 CaCO3 i + H2O
    [0255] Mg (HCO3) 2+ Ca (OH) 2 - CaCO3 MgCO3 2H2O
    [0256]
    [0257] MgCO3 + Ca (OH) 2 - - M g ^ (OH) 2 i + CaCO3 i
    [0258] Mg SO4 + Ca (OH) 2 - Mg (OH) 2 i + CaSO4
    [0259] MgCl2 + Ca (OH) 2 - Mg (OH) 2 i + CaCl2
    [0260] CaSO4 + Na2CO3 - - CaCO3 i + Na2SO4
    [0261] CaCl2 + Na2CO3 - CaCO3 i + 2NaCl
    [0262]
    [0263] When lime is added, the calcium reacts with the carbonates present in the reject water plus the carbonates added with the sodium carbonate and precipitates as calcium carbonate, OH- ions combine with magnesium to precipitate as magnesium hydroxide.
    [0264]
    [0265] Once these reactions have been carried out and the calcium and magnesium have precipitated in the third and fourth precipitate tanks (7, 8), a second pump (B2) drives the flow through a fourth section (T4) until the second filtering means (10), in which a filtering (31) of the flow is carried out.
    [0266]
    [0267] Before and after these second filter media (10) there are taps (TM) for sampling.
    [0268]
    [0269] Finally, a fifth phase of neutralization (32) of the pH of the pre-treated water takes place and storage (33) thereof in a final tank (11).
    [0270]
    [0271] Said neutralization is carried out by adding 35% hydrochloric acid that is contained in a containment tank (D5) and is added by means of a dosing device (17) thereof in a section of the fifth section (T5) of the circuit.
    [0272]
    [0273] After neutralization (32) by addition of hydrochloric acid, the whole is mixed (37) in a third mixing device (38) by turbulence, a pH measurement is carried out and stored in a final tank (11).
    [0274]
    [0275] This final tank (11) has an outlet pump (B4) to drive the pretreated water to a revaluation equipment and with valves (V4) to take samples, to eliminate possible precipitates and to control the flow.
    [0276]
    [0277] Furthermore, the water circulation circuit comprises a series of conductivity meters (C) to control the conductivity of the water.
    [0278]
    [0279] As shown in Figure 6, in this preferred embodiment of the invention, the treatment process comprises a final phase of applying a reverse osmosis treatment (36) on the pretreated water. This final phase takes place after neutralization (32) of the pH of the water and prior to its storage (33) in the tank.
    [0280] Thanks to the completion of this final phase, a percentage of water suitable for use is extracted from the process over the pre-treated water and a remaining percentage of reject water is stored in the final tank.
    [0281]
    [0282] In this preferred embodiment of the invention, the first cycle of the process is carried out with solutions of the reagents made with tap water, while in subsequent cycles thereof, these solutions are carried out with the pretreated water.
    [0283]
    [0284] The described embodiment constitutes only an example of the present invention, therefore, the specific details, terms and phrases used herein are not to be considered as limiting, but are to be understood solely as a basis for claims and as a representative basis that provides an understandable description as well as sufficient information to the person skilled in the art to apply the present invention.
    权利要求:
    Claims (1)
    [0001]
    1- Equipment (1) for pretreatment of the reverse osmosis rejection water, for use in obtaining sodium hypochlorite by means of an electrolysis reaction, characterized in that it comprises
    - sulfate removal means comprising a first and a second precipitate tank (2, 3) connected by overflow, where the first tank (2) is connected to an inlet of the equipment by means of a first section (T1) of a circuit for circulation of the water that has, connected to it according to the direction of the flow, an oxygenation means (4), means for dosing a first reagent suitable for reacting with sulfate ions in the water and a first mixing device (5) and, first filtering means (6) connected to the second tank (3) by means of a second section (T2) that has a first pump (B1);
    - water hardness removal means comprising a third and a fourth (7, 8) overflow connected precipitate tanks, where the third tank (7) is connected to the first filter means (6) by a third section (T3) that has connected to it according to the flow direction, dosing means of at least one second and a third reagents capable of reacting with calcium and magnesium and a second mixing device (9) and, a second means filter (10) connected to the fourth tank (8) by a fourth section (T4) that has a second pump (B2);
    - where the first and second mixing device (5, 9) are formed by a turbulence mixer, connected to the corresponding section in an intercalated manner such that water passes through it from a first to a second end thereof, and; - a final tank (11) for storing water, connected to the second filter media (10) by means of a fifth section (T5) that has means for neutralizing the pH.
    2- Reverse osmosis rejection water pretreatment equipment (1), according to claim 1, characterized in that the means for dosing a first reagent are formed by a containment tank (D1) of the same, comprising means for stirring and a dosing device (12) for the first reagent in a section of the first section (T1) of the circuit, where the first reagent is made up of a dilute barium hydroxide solution.
    3- Reverse osmosis rejection water pretreatment equipment (1), according to any of the preceding claims, characterized in that the dosing means of at least one second and third reagents are formed by respective containment tanks (D2, D3 ) thereof, which comprise stirring means respectively and respective dosing devices (13, 14) of the second and third reagents in a section of the third section (T3), where said second and third reagents are respectively formed by a hydroxide solution of calcium and a sodium carbonate solution.
    4- Reverse osmosis rejection water pretreatment equipment (1), according to claim 3, characterized in that it comprises means for dosing a fourth reagent in a section of the third section (T3) prior to the second mixing device (9), formed by a containment tank (D4) of the fourth reagent and a dosing device (15) thereof, where the fourth reagent is formed by sodium hydroxide.
    5- Reverse osmosis rejection water pretreatment equipment (1), according to any of the preceding claims, characterized in that it comprises additional oxygenation means (16) of the water in a section of the third section (T3) previously to the second mixing device (9).
    6- Reverse osmosis rejection water pre-treatment equipment (1), according to any of the preceding claims, characterized in that the pH neutralization means are formed by a containment tank (D5) of a pH neutralization reagent and a dosing device (17) thereof in a section of the fifth section (T5) of the circuit, where the neutralization reagent is formed by 35% hydrochloric acid.
    7- Reverse osmosis rejection water pretreatment equipment (1), according to any of the preceding claims, characterized in that the first and second filtering means (6, 10) comprise a first filter (6.1, 10.1) and a second cartridge filter (6.2, 10.2) connected in parallel to the corresponding section, with control valves (VC) that allow flow to pass through the first or second filter.
    8- Reverse osmosis rejection water pretreatment equipment (1), according to any of the previous claims, characterized in that the precipitate deposits (2, 3, 7, 8) comprise a valve for the elimination of precipitated salts (V1 .1), where in addition the first and third precipitate tanks (2, 7) comprise a waste water removal valve (V1.2) and where the second and fourth precipitate tanks (3, 8) comprise a discharge valve regulation (V2) of the flow outlet.
    9- Reverse osmosis rejection water pre-treatment equipment (1), according to any of the preceding claims, characterized in that it comprises an initial filtering device (18) arranged in the first section (T1) in a section thereof, prior to the sulfate removal means connected to it.
    10- Reverse osmosis rejection water pre-treatment equipment (1), according to any of the preceding claims, characterized in that it comprises flow regulation means at the circuit inlet formed by an inlet pump (B3) and two valves regulating valve (V3) and, means for regulating the output flow of the circuit from the final storage tank (11), formed by an output pump (B4) and respective regulation valves (V4).
    11- Reverse osmosis rejection water pre-treatment equipment (1), according to any of the previous claims, characterized in that the oxygenation means (4, 16) are formed by a blower or by an addition of chemicals, formed by hydrogen peroxide or another with similar oxygenating characteristics.
    12- Reverse osmosis rejection water pretreatment process, by means of a pretreatment equipment (1) as defined in claims 1 to 11, characterized in that it comprises the following phases
    - inlet (21) of the reject water in the equipment circuit (1);
    - removal of manganese and / or iron present in the reject water by adding oxygen (23) with oxygenation means (4);
    - removal of sulfates by adding a first reagent (24) suitable for reacting with sulfate ions from water, mixing (25) thereof with a first mixing device (5) and a precipitate (26) of sulfates up to bottom of a first precipitate tank (2) and a second precipitate tank (3) connected by overflow with the first;
    - elimination of the hardness of the reject water by adding at least one second and a third reagent (28) capable of reacting with the calcium and magnesium present therein, mixing (29) in a second mixing device ( 9) and a precipitate (30) of calcium and magnesium to the bottom of a third precipitate tank (7), and a fourth precipitate tank (8) connected by overflow with the third;
    - where after the precipitate in the second and fourth precipitate deposits (3, 8), a filtering (27, 31) of the particles in suspension of the water is carried out by means of first and second filtering means (6, 10) respectively;
    - neutralization of the pH (32) of the pretreated water and storage (33) of it in a final tank.
    13- Reverse osmosis rejection water pretreatment process, according to claim 12, characterized in that it comprises a final phase of applying a reverse osmosis treatment (36) to the pretreated water, after neutralization (32) of the pH of the water and prior to its storage (33) in the tank, such that a percentage of water suitable for use is obtained that is extracted from the process and a remaining percentage of reject water that is stored in the final tank (11) .
    14- Reverse osmosis rejection water pretreatment process, according to any of claims 12 and 13, characterized in that the phase of elimination of the hardness of the rejection water comprises a sampling (TM) prior to the addition of the second and third reagents (28).
    15- Reverse osmosis rejection water pretreatment process, according to claim 14, characterized in that it comprises a phase of adding a fourth reagent (34), prior to the mixing phase (29) in the second mixing device (9), to control the pH of the water, when the sample analyzed in the sampling has a pH lower than 12 (TM1).
    16- Reverse osmosis rejection water pretreatment process, according to any of claims 14 and 15, characterized in that it comprises an additional phase of introducing oxygen (35) into the water, prior to mixing (29) in a second mixing device (9), by means of additional oxygenation means (16), when the sample analyzed in the sampling shows traces of manganese and / or iron (TM3).
    17- Reverse osmosis rejection water pretreatment process, according to any of claims 12 to 16, characterized in that it comprises an initial filtering (22) prior to the addition of oxygen (23) by means of oxygenation (4) .
    18- Reverse osmosis rejection water pre-treatment process, according to any of claims 12 to 17, characterized in that in a first cycle of the process, the solutions of the reagents used are carried out with mains water and in subsequent cycles of the They are made with pretreated water.
    类似技术:
    公开号 | 公开日 | 专利标题
    US20210107806A1|2021-04-15|Methods and systems for producing treated brines
    US9056784B2|2015-06-16|High efficiency water-softening process
    KR100190220B1|1999-06-01|Water treating method and apparatus treating waste water by using ion exchange resin
    US20160244349A1|2016-08-25|Production of ultra-high-density brines
    US8147696B1|2012-04-03|High-efficiency water-softening process
    US20110163032A1|2011-07-07|High recovery sulfate removal process
    US20190127253A1|2019-05-02|Method and device for treating water condensed from water vapor contained in the air, and related method and system for generating potable water
    CN104291416A|2015-01-21|Low energy system and method of desalinating seawater
    WO2004087586A1|2004-10-14|Process for treating concentrated salt solutions containing doc
    Tabatabai et al.1995|Economic feasibility study of polyelectrolyte-enhanced ultrafiltration | for water softening
    Schoeman et al.2001|Investigation into alternative water treatment technologies for the treatment of underground mine water discharged by Grootvlei Proprietary Mines Ltd into the Blesbokspruit in South Africa
    Solutions2010|Filmtec™ Reverse Osmosis Membranes
    Jin et al.2020|Sequential combination of nanofiltration and ettringite precipitation for managing sulfate-rich brines
    US20170240448A1|2017-08-24|Integrated system for chemical reaction, sedimentation and oxidation in water treatment processes
    CN106430780A|2017-02-22|Heat-engine plant wastewater treatment method and system
    ES2759489A2|2020-05-11|Reverse osmosis rejection water pretreatment equipment and pretreatment process using said equipment |
    AU2009200113A1|2009-08-20|Water purification
    CN107601729A|2018-01-19|For the dense salt waste water zero discharge treatment process of steel industry and system
    RU2590543C1|2016-07-10|Block-modular water treatment station for water supply systems
    CN107265696A|2017-10-20|A kind of desulfurization wastewater sofening treatment device and method
    CN207121501U|2018-03-20|A kind of hardness removing device suitable for the hard waste water of high magnesium
    RU2477707C2|2013-03-20|Method of water cleaning and decontamination
    Abdel-Jawad et al.1997|Pretreatment of the municipal wastewater feed for reverse osmosis plants
    RU2686146C1|2019-04-24|Water degassing method
    RU2220115C1|2003-12-27|Drinking water production process
    同族专利:
    公开号 | 公开日
    ES2759489R1|2020-05-25|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US7320756B2|2001-05-05|2008-01-22|Debasish Mukhopadhyay|Method and apparatus for treatment of feedwaters by membrane separation under acidic conditions|
    US20100163471A1|2008-12-30|2010-07-01|Irving Elyanow|Water desalination plant and system for the production of pure water and salt|
    US20120160753A1|2008-12-30|2012-06-28|Nishith Vora|Water desalination plant and system for the production of pure water and salt|
    US9255023B2|2012-04-17|2016-02-09|Water Solutions, Inc.|Treatment of contaminated impound water|
    法律状态:
    2020-05-11| BA2A| Patent application published|Ref document number: 2759489 Country of ref document: ES Kind code of ref document: A2 Effective date: 20200511 |
    2020-05-25| EC2A| Search report published|Ref document number: 2759489 Country of ref document: ES Kind code of ref document: R1 Effective date: 20200518 |
    2021-07-26| FC2A| Grant refused|Effective date: 20210720 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES201831052A|ES2759489R1|2018-10-30|2018-10-30|Reverse osmosis rejection water pretreatment equipment and pretreatment process using said equipment|ES201831052A| ES2759489R1|2018-10-30|2018-10-30|Reverse osmosis rejection water pretreatment equipment and pretreatment process using said equipment|
    [返回顶部]