TWI851501B - Control Methods for Seawater Minerals - Google Patents

Abstract

A method for regulating seawater minerals comprises the following steps: providing a seawater concentrate, and passing the seawater concentrate through an anion exchange resin for adsorbing boron ions to obtain a treated seawater concentrate. The seawater concentrate contains a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. The treated seawater concentrate contains a boron ion concentration of less than 60 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. The seawater mineral control method of the present invention can effectively reduce the boron ion concentration while maintaining the original magnesium ion concentration, and the prepared treated seawater concentrate can be used to prepare drinking water that meets the standards of the World Health Organization.

Description

Control Methods for Seawater Minerals

The present invention relates to a method for treating seawater, and more particularly to a method for regulating seawater minerals.

Deep seawater below 200 meters below sea level cannot photosynthesize because sunlight cannot penetrate, so it can retain a higher content of inorganic nutrients. Currently, deep seawater has been widely used in beverages, food, medicines and aquaculture, making the purification and treatment of deep seawater a research focus in the industry.

Among the ions contained in deep seawater, magnesium and calcium ions are of greatest concern, because in the human body, the ratio of magnesium to calcium ions affects the functioning of muscle tissue, the nervous system, etc. For adults, the Department of Health recommends a daily intake of magnesium and calcium minerals of 315-350 mg/day of magnesium and 1000 mg/day of calcium. Based on the above considerations, many literatures and patents have been reported on how to maintain the magnesium and calcium ion content in deep seawater. For example, the patent publication of the Republic of China TW I428292B proposes a method for preparing a seawater concentrate, which includes subjecting a concentrated brine to electrodialysis through a divalent anion membrane to obtain a sulfate-free mineral water; then the sulfate-free mineral water is subjected to concentration and separation treatment to obtain a seawater concentrate and mineral salts. The seawater concentrate has a low content of sulfate ions and sodium ions, and a high content of magnesium ions and calcium ions. This patent announcement is mainly intended to produce a seawater concentrate having low content of sulfate ions and sodium ions, and high content of magnesium ions and calcium ions.

As deep seawater is increasingly used for health and medical purposes, it has been found that excessive boron ions in deep seawater can induce many diseases after long-term exposure to the human body. Therefore, how to effectively remove excess boron ions in deep seawater has become another key research and development project. The World Health Organization (WHO) stipulates a boron ion limit of 0.5 mg/L in its drinking water quality standards, while the EU stipulates a boron ion limit of 1 mg/L. However, looking at the existing seawater boron removal technologies [including multi-stage reverse osmosis (RO), electrodialysis, adsorption, chemical precipitation and ion exchange resin technologies], these technologies cannot effectively reduce the boron content while maintaining the original concentration of magnesium ions, nor can they be industrialized for large-scale treatment. Taking multi-stage reverse osmosis as an example, although the technology of using multi-stage reverse osmosis to treat seawater can remove boron ions in seawater, there is no selectivity difference for all ions. While removing boron ions, magnesium ions, calcium ions and other ions will also be removed at the same time, so multi-stage reverse osmosis technology cannot effectively maintain the magnesium ion content in deep seawater.

Since existing methods cannot effectively reduce the concentration of boron ions while maintaining the original concentration of magnesium ions, the industry is still in urgent need of finding better methods for removing boron from seawater.

Therefore, the purpose of the present invention is to provide a method for regulating seawater minerals, which can effectively reduce the concentration of boron ions while maintaining the original concentration of magnesium ions, and the obtained treated seawater concentrate can be used to prepare drinking water that meets the standards of the World Health Organization.

Therefore, the seawater mineral control method of the present invention comprises the following steps: Providing a seawater concentrate containing a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L; and Passing the seawater concentrate through an anion exchange resin for adsorbing boron ions to obtain a treated seawater concentrate, wherein the treated seawater concentrate contains a boron ion concentration of less than 60 mg/L and a minimum magnesium ion concentration of 40,000 mg/L.

In some specific embodiments of the present invention, the concentrated seawater contains boron ions in a concentration range of 140-300 mg/L.

In some specific embodiments of the present invention, the concentrated seawater contains magnesium ions in a concentration range of 40,000-120,000 mg/L.

In some specific embodiments of the present invention, the concentrated seawater further contains calcium ions in a concentration range of 120-19,000 mg/L.

In some specific embodiments of the present invention, the pH value of the concentrated seawater is in the range of 6-7.

In some embodiments of the present invention, the minimum total hardness of the treated seawater concentrate is 186,500 mg/L.

In some specific examples of the present invention, the seawater concentrate is obtained by subjecting deep seawater to a reverse osmosis step, a low-temperature pressure reduction concentration step, a cooking and desalination step, an ion blending step, and a filtration step.

In some specific examples of the present invention, the deep seawater is seawater located below 200 meters below sea level, the hardness of the deep seawater ranges from 6,000 to 7,000 mg/L, and the minimum concentration of silicate is 20 μM.

In some specific examples of the present invention, the control method of the present invention further comprises a dilution step, wherein the treated seawater concentrate is diluted to obtain a regulated seawater, wherein the regulated seawater contains a boron ion concentration of less than 0.5 mg/L.

In some embodiments of the present invention, the regulated seawater contains magnesium ions in a concentration range of 240-300 mg/L.

The efficacy of the present invention is that the present invention uses a seawater concentrate containing a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L, and then passes through an anion exchange resin for adsorbing boron ions to effectively reduce the boron ion concentration while maintaining the original magnesium ion concentration. The seawater concentrate of the present invention can be used to prepare drinking water that meets the standards of the World Health Organization, or used in other fields (such as other beverages, food, pharmaceuticals and aquaculture, etc.).

The seawater mineral control method of the present invention comprises the following steps: providing a seawater concentrate, and passing the seawater concentrate through an anion exchange resin for adsorbing boron ions to obtain a treated seawater concentrate. The seawater concentrate contains a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. The treated seawater concentrate contains a boron ion concentration of less than 60 mg/L and a minimum magnesium ion concentration of 40,000 mg/L.

The term "seawater mineral" mentioned in the present invention refers to any mineral obtained by processing seawater, such as but not limited to minerals containing magnesium ions, calcium ions, or potassium ions.

The "minimum concentration of 140 mg/L" mentioned in the present invention means the concentration is ≥ 140 mg/L; and the "minimum concentration of 40,000 mg/L" means the concentration is ≥ 40,000 mg/L. "Concentration less than 60 mg/L" means the concentration is less than 60 mg/L.

The "deep seawater" mentioned in the present invention generally refers to seawater located in the ocean thermocline layer, or seawater located below 200 meters below sea level. Preferably, the deep seawater is seawater located below 200 meters below sea level, the hardness range of the deep seawater is 6,000-7,000 mg/L, and the minimum silicate concentration is 20 μM.

Preferably, the seawater concentrate is obtained by treating seawater. The above-mentioned "treatment" must satisfy the conditions for obtaining a seawater concentrate containing a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. The treatment includes but is not limited to: reverse osmosis step, low temperature and reduced pressure concentration step, cooking and desalination step, ion blending step, filtration step, etc. The reverse osmosis step, for example, allows the seawater to pass through a reverse osmosis filtration circulation device, which may include one or more reverse osmosis filtration devices connected in series or in parallel and containing multi-pass filter membranes. The low-temperature decompression concentration step, for example, places the seawater in a low-temperature vacuum concentration device for low-temperature decompression concentration to obtain concentrated seawater. The desalination step, for example, introduces seawater into a desalination device; and heats the seawater under low pressure to boil and vaporize the water, while allowing carbonates, sulfates, chlorides and other salts in the seawater to reach supersaturation, and then continuously precipitates and crystallizes the seawater to the desired composition concentration. The ion blending step uses deionized water to dilute the desalinated seawater to the desired composition concentration. The filtering step is to filter the seawater through a micro-nano membrane.

More preferably, the seawater concentrate is obtained by subjecting deep seawater to a reverse osmosis step, a low-temperature reduced-pressure concentration step, a steaming and desalting step, an ion blending step, and a filtering step. More specifically, the deep seawater is obtained by the following steps: (1) passing the deep seawater through a reverse osmosis filtration device comprising a plurality of reverse osmosis filtration devices, and utilizing the reverse osmosis filtration devices to dehydrate the deep seawater and intercept minerals, and further concentrating the mineral concentration in the deep seawater to a concentration suitable for subsequent steps, so as to obtain a first treated seawater, wherein, preferably, the first treated seawater has a minimum total hardness of 8,000 mg/L; (2) introducing the first treated seawater into a low-temperature vacuum concentration device for low-temperature decompression concentration (e.g., a temperature of 60°C and a pressure of 600°C); (3) introducing the second treated seawater into a boiling device, and then heating the second treated seawater in a low pressure environment (e.g., a temperature of 120°C and a pressure of 760 mmHg) to allow the water contained therein to boil and vaporize, and to allow the salts to be supersaturated and continuously crystallize, and wait for the second treated seawater to continuously crystallize to a desired ion concentration, and finally filter out the liquid to obtain a third treated seawater, wherein, preferably, the third treated seawater has a minimum total hardness of 300,000 mg/L, a minimum magnesium ion concentration of 70,000 mg/L, and a minimum boron ion concentration of 250 (4) diluting the third treated seawater with deionized water to adjust the ion concentration of the third treated seawater to obtain a fourth treated seawater, wherein, preferably, the fourth treated seawater has a minimum total hardness of 165,000 mg/L, a minimum magnesium ion concentration of 40,000 mg/L, and a minimum boron ion concentration of 140 mg/L; (5) filtering the fourth treated seawater through a nanofiltration membrane (e.g., with a pore size of 0.2 μm) to obtain the seawater concentrate.

The seawater concentrate contains a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. Preferably, the seawater concentrate contains a boron ion concentration in the range of 140-300 mg/L. More preferably, the seawater concentrate contains a magnesium ion concentration in the range of 40,000-120,000 mg/L. In addition to maintaining the content of magnesium ions, the content of other mineral substances, such as calcium ions, sodium ions, phosphorus ions, etc., can also be maintained as needed. More preferably, the concentrated seawater further contains calcium ions in a concentration range of 120-19,000 mg/L; even more preferably, the concentrated seawater further contains calcium ions in a concentration range of 120-13,000 mg/L.

It should be noted that when the seawater concentrate contains boron ions at a concentration below 140 mg/L, even if it is passed through an anion exchange resin for adsorbing boron ions, the boron ion concentration cannot be effectively reduced. This is because the anion exchange resin for adsorbing boron ions has the characteristic of exchanging high-concentration boron ions. Therefore, when the boron ion concentration is too low, the anion exchange resin will not be able to adsorb boron ions and cannot effectively remove boron ions. Secondly, when the seawater concentrate contains magnesium ions at a concentration of 40,000 mg/L or less, it is not possible to obtain a treated seawater concentrate containing a high magnesium ion concentration even if it passes through the anion exchange resin.

Preferably, the pH value of the concentrated seawater is in the range of 6 to 7. In some embodiments of the present invention, the pH value of the concentrated seawater is in the range of 6.8.

Preferably, the seawater concentrate has a minimum total hardness of 165,000 mg/L.

The seawater concentrate passes through the anion exchange resin to obtain the treated seawater concentrate. The anion exchange resin is used to adsorb boron ions, for example, an anion exchange resin with N-methylglucamine functional groups or a macroporous styrene resin. Preferably, the anion exchange resin is an anion exchange resin with N-methylglucamine functional groups. The anion exchange resin with N-methylglucamine functional groups has a highly specific adsorption effect on boric acid or borate ions.

The treated seawater concentrate contains boron ions at a concentration of less than 60 mg/L and magnesium ions at a minimum concentration of 40,000 mg/L. Preferably, the treated seawater concentrate contains boron ions at a concentration of less than 60 mg/L and magnesium ions at a minimum concentration of 40,000 mg/L.

Preferably, the treated seawater concentrate has a minimum total hardness of 186,500 mg/L.

Preferably, the seawater mineral control method of the present invention further comprises a dilution step, wherein the treated seawater concentrate is diluted to obtain a regulated seawater, wherein the regulated seawater contains a boron ion concentration of less than 0.5 mg/L.

Preferably, the regulated seawater contains magnesium ions in a concentration range of 240-300 mg/L. In addition to the above concentration range, the magnesium ion concentration range can also be adjusted according to subsequent application requirements, for example, the concentration range is 5-300 mg/L, and specific concentrations are, for example, but not limited to, 7.1, 23.6, 70.9, 141.8 mg/L and 260 mg/L.

The regulated seawater can be used in beverages, food, medicines, aquaculture and other fields. The above-mentioned seawater concentrate can also be directly used in the above-mentioned fields. [ Example ]

The present invention will be further described with respect to the following embodiments, but it should be understood that the embodiments are only for illustrative purposes and should not be interpreted as limitations on the implementation of the present invention.

The following examples and comparative examples all use deep seawater and use the following instruments for property testing: 1.   The deep seawater is deep seawater located below 200 meters below sea level. This deep seawater has a total hardness of 6,000~7,000 mg/L and a minimum silicate concentration of 20μM. 2.   Ion concentration (mg/L), hardness (mg/L): measured using an inductively coupled plasma atomic emission spectrometer (ICP-OES, Perkin Elmeroptima 2100DV). 3.   pH value: measured using a pH acidity meter.

[ Example 1] 1. Preparation of seawater concentrate: (1) Deep seawater is passed through a reverse osmosis filtration device [manufactured by AMI, Inc., USA, model number M-S4040A] to dehydrate the deep seawater and retain minerals, and further increase the mineral concentration to obtain a first treated seawater (minimum total hardness of 8,000 mg/L). (2) The first treated seawater is introduced into a low-temperature decompression concentration device and concentrated at a temperature of 60°C and a pressure of 600 mmHg to obtain a second treated seawater. (3) The second treated seawater is introduced into a cooking device (a stainless steel steam rotary pot, manufactured by Taiwan Fenglong Iron Works, model 560L). The second treated seawater is then heated at a temperature of 120°C and a pressure of 760 mmHg to allow the water contained therein to boil and vaporize, and to allow the salts to be supersaturated and continuously crystallize and precipitate. The second treated seawater continues to crystallize and precipitate to the desired ion concentration, and finally the liquid is filtered out to obtain a third treated seawater. The third treated seawater has a minimum total hardness of 300,000 mg/L, a minimum magnesium ion concentration of 70,000 mg/L, and a minimum boron ion concentration of 250 mg/L. (4) The third treated seawater is diluted with deionized water to adjust the ion concentration of the third treated seawater, thereby obtaining a fourth treated seawater. The fourth treated seawater has a minimum total hardness of 165,000 mg/L, a minimum magnesium ion concentration of 40,000 mg/L, and a minimum boron ion concentration of 140 mg/L. (5) The fourth treated seawater is filtered through a nanofiltration membrane [pore size 0.2 μm, manufactured by AMI, USA, model number M-N4040A5] to obtain the seawater concentrate. The seawater concentrate contains magnesium ions at a concentration of 45,441 mg/L, calcium ions at a concentration of 130 mg/L, and boron ions at a concentration of 142.6 mg/L. The pH value of the seawater concentrate is 6.8. 2. Preparation of treated seawater concentrate: The above-mentioned seawater concentrate was subjected to an anion exchange resin column containing N-methylglucosamine functional groups (resin filling volume of 16.5 L, manufactured by DuPont, USA, model IRA743) under the control conditions of temperature 25°C, batch processing volume 300 L and flow rate 100 L/h to obtain the treated seawater concentrate of Example 1. The treated seawater concentrate contained magnesium ions at a concentration of 45,441 mg/L and boron ions at a concentration of 24.5 mg/L. The total hardness of the treated seawater concentrate was 187,450 mg/L. 3. Preparation of conditioned seawater: The treated seawater concentrate of Example 1 was diluted by reverse osmosis filtration to obtain conditioned seawater. The conditioned seawater contained 270 mg/L of magnesium ions, 0.15 mg/L of boron ions, 2,000 mg/L of sodium ions, and 2,000 mg/L of potassium ions.

[ Example 2] Except for adjusting the flow rate to 600 mg/L, the remaining steps and conditions are the same as those of Example 1. The treated seawater concentrate prepared in Example 2 contains 42,715 mg/L of magnesium ions and 53.7 mg/L of boron ions, and the total hardness of the treated seawater concentrate is 187,450 mg/L. The treated seawater concentrate of Example 2 is diluted by reverse osmosis filtered water to obtain a regulated seawater. The conditioned seawater thus produced contained magnesium ions at a concentration of 270 mg/L, boron ions at a concentration of 0.32 mg/L, sodium ions at a concentration of 2,000 mg/L and potassium ions at a concentration of 2,000 mg/L.

[ Comparative Example 1] Deep seawater was filtered to obtain purified seawater. The purified seawater contained magnesium ions at a concentration of 1,300 mg/mL, boron ions at a concentration of 4-5 mg/mL, and calcium ions at a concentration of 500 mg/mL. The pH value of the purified seawater was 7.8-8.5. Under the control conditions of temperature 25°C, batch processing volume 300 L, and flow rate 100 L/h, the purified seawater was subjected to an anion exchange resin column containing N-methylglucosamine functional groups (resin filling volume of 16.5 L) to obtain the treated seawater of Comparative Example 1. The treated seawater contained 1,300 mg/L of magnesium ions and 1-2 mg/L of boron ions. The treated seawater of Comparative Example 1 was diluted with reverse osmosis filtered water to obtain regulated seawater. The regulated seawater contained 270 mg/L of magnesium ions, 0.42 mg/L of boron ions, 15,000 mg/L of sodium ions, and 450 mg/L of potassium ions.

[ Comparative Example 2] Deep seawater is coarsely filtered through a filter membrane with a pore size of 1 μm, and then desalinated through a first reverse osmosis membrane [manufactured by AMI, USA, model M-S4040A] to obtain primary desalinated seawater. The primary desalinated seawater is then passed through a second reverse osmosis membrane [manufactured by AMI, USA, model M-S4040A] to obtain secondary desalinated seawater. The secondary desalinated seawater contains magnesium ions with a concentration of less than 1 mg/L, boron ions with a concentration of 4-5 mg/L, and calcium ions with a concentration of less than 1 mg/L. With the temperature of 25°C, the batch processing volume of 300 L and the flow rate of 100 L/h as the control conditions, the secondary desalinated seawater was used in an anion exchange resin column containing N-methylglucosamine functional groups (resin filling volume of 16.5 L) to obtain the treated seawater of Comparative Example 2. The treated seawater contained magnesium ions with a concentration of less than 1 mg/L and boron ions with a concentration of 0.8-1.5 mg/L. The treated seawater of Comparative Example 2 was diluted with reverse osmosis filtered water to obtain a regulated seawater. The conditioned seawater contains magnesium ions at a concentration of less than 1 mg/L, boron ions at a concentration of 0.8-1.5 mg/L, sodium ions at a concentration of less than 10 mg/L and potassium ions at a concentration of less than 10 mg/L.

The above-mentioned Example 1, Comparative Example 1 and Comparative Example 2 are compared as shown in Table 1 below, wherein the calculation formulas for the magnesium ion retention rate and the boron ion removal rate are as follows (taking seawater concentrate as an example): Magnesium ion retention rate (%) = (magnesium ion concentration contained in the treated seawater concentrate/magnesium ion concentration contained in the seawater concentrate) × 100% Boron ion removal rate (%) = [(boron ion concentration contained in the seawater concentrate – boron ion concentration contained in the treated seawater concentrate)/boron ion concentration contained in the seawater concentrate] × 100% Table 1 Embodiment 1 Comparison Example 1 Comparison Example 2 Ion concentration in seawater concentrate, purified seawater or secondary desalinated seawater (mg/L) Magnesium ion 45441 1300 ＜1 Calcium ions 130 500 ＜1 Boron ions 142.6 4-5 4-5 Properties of treated seawater concentrate or treated seawater Magnesium ion concentration (mg/L) 45441 1300 ＜1 Boron ion concentration (mg/L) 24.5 1~2 0.8~1.5 Magnesium ion retention rate 100% 100% Content is too low to be calculated Boron ion removal rate 83% 75% 80% Ion concentration in regulated seawater (mg/L) Magnesium ion 270 270 ＜1 Boron ions 0.15 0.42 0.8~1.5 Sodium ion 2000 15000 ＜10 Potassium ion 2000 450 ＜10 Whether the regulated seawater meets the WTO drinking water standard (boron ion concentration less than 0.5 mg/L) yes no no

According to the results in Table 1, although Comparative Example 1 and Comparative Example 2 can also retain magnesium ions and remove boron ions, the regulated seawater finally produced cannot meet the WTO drinking water standards. For Comparative Example 1, although the magnesium ion concentration and boron ion concentration both meet the standards, because the deep seawater in Comparative Example 1 has not undergone more rigorous filtration or other concentration and purification steps, the sodium ion in the purified seawater seriously exceeds the standard, and the deep seawater may also contain other metal ions. Therefore, the purified seawater cannot be used directly as drinking water. As for Comparative Example 2, although the regulated seawater of Comparative Example 2 contains sodium ion concentration and potassium ion concentration that meet the standards, the boron ion concentration is too high and cannot meet the WTO drinking water standard. As for Example 1, the regulated seawater of Example 1 can not only maintain a relatively high concentration of magnesium ions, sodium ions and potassium ions that meet the standard concentrations, but also contains a low concentration of boron ions that meet the standards, so the regulated seawater of Example 1 can be used as drinking water.

The results of Example 1 and Example 2 are summarized in Table 2: Table 2 Embodiment 1 Embodiment 2 Ion concentration in seawater concentrate (mg/L) Magnesium ion 45441 45441 Calcium ions 130 130 Boron ions 142.6 142.6 Properties of Treated Seawater Concentrate Magnesium ion concentration (mg/L) 45441 42715 Boron ion concentration (mg/L) 24.5 53.7 Magnesium ion retention rate 100% 94% Boron ion removal rate 83% 62.3% Ion concentration in regulated seawater (mg/L) Magnesium ion 270 270 Boron ions 0.15 0.32 Sodium ion 2000 2000 Potassium ion 2000 2000 Whether the regulated seawater meets the WTO drinking water standard (boron ion concentration less than 0.5 mg/L) yes yes

According to the results in Table 2, Example 2 increases the flow rate by 6 times (from 100 L/h to 600 L/h), which results in a decrease in the magnesium ion retention rate and the boron ion removal rate, and the boron ion concentration of the regulated seawater is also slightly increased. However, the regulated seawater still meets the WTO drinking water standard. The results of Example 2 also show that the regulation method of the present invention can treat deep seawater in large quantities, and can effectively reduce the boron ion concentration while maintaining a relatively high magnesium ion concentration, thereby obtaining regulated seawater that meets the WTO drinking water standard.

[ Examples 3-7] Except for adjusting the flow rate to 60 mg/L, 200 mg/L, 300 mg/L, 400 mg/L and 500 mg/L, the remaining steps and conditions are the same as those of Example 1. The ion concentrations of the treated seawater concentrates obtained in Examples 3-7 are shown in Table 3. The magnesium ion retention rate and the boron ion removal rate are calculated according to the above paragraph [0041], and the calcium ion retention rate is calculated as follows. The results are summarized in Table 3. Calcium ion retention rate (%) = (calcium ion concentration in treated seawater concentrate/calcium ion concentration in seawater concentrate) × 100%

Table 3 Embodiment 3 1 4 5 6 7 2 Flow rate (L/h) 60 100 200 300 400 500 600 Properties of Treated Seawater Concentrate Magnesium ion concentration (mg/L) 46359 47520 47644 47965 46930 43927 47573 Boron ion concentration (mg/L) 20.9 24.5 32.7 40.1 42.13 44.7 53.7 Calcium ion concentration (mg/L) 126.8 126.2 130.5 128.9 128.5 130.5 127.8 Magnesium ion retention rate 100% 100% 100% 100% 100% 96.7% 94.0% Calcium ion retention rate 99.5% 99.1% 102.4% 101.2% 100.9% 102.4% 100.3% Boron ion removal rate 85.3% 82.8% 77.1% 71.9% 70.5% 68.7% 62.3%

From Table 3, the present invention can effectively achieve a boron ion removal rate of 62.3% to 85.3% with a magnesium ion retention rate of more than 94%. Although the increase in flow rate will affect the retention rate of magnesium ions and calcium ions, and the boron ion removal rate, from the results of Examples 1 and 2 in Table 2, the final regulated seawater will still meet the WTO drinking water standards. It can be seen that the regulated seawater can meet the WTO drinking water standards when the flow rate is controlled below 600 L/h.

In summary, the seawater mineral control method of the present invention uses a concentrated seawater solution containing a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L, and then passes through an anion exchange resin for adsorbing boron ions. The boron ion concentration can be effectively reduced while maintaining the original magnesium ion concentration, so the purpose of the present invention can be achieved.

However, the above is only an example of the implementation of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the patent of the present invention.

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Claims (10)

A method for regulating seawater minerals comprises the following steps: Providing a seawater concentrate containing a minimum boron ion concentration of 140 mg/L and a minimum magnesium ion concentration of 40,000 mg/L; and Passing the seawater concentrate through an anion exchange resin for adsorbing boron ions to obtain a treated seawater concentrate, wherein the treated seawater concentrate contains a boron ion concentration of less than 60 mg/L and a minimum magnesium ion concentration of 40,000 mg/L. A control method as described in claim 1, wherein the concentrated seawater contains boron ions in a concentration range of 140-300 mg/L. The control method as described in claim 1, wherein the concentrated seawater contains magnesium ions in a concentration range of 40,000 to 120,000 mg/L. The control method as described in claim 1, wherein the concentrated seawater also contains calcium ions in a concentration range of 120 to 190,000 mg/L. The control method as described in claim 1, wherein the pH value of the concentrated seawater is in the range of 6-7. The control method as described in claim 1, wherein the minimum total hardness of the treated seawater concentrate is 186,500 mg/L. The control method as described in claim 1, wherein the seawater concentrate is obtained by subjecting deep seawater to a reverse osmosis step, a low-temperature reduced-pressure concentration step, a steaming and desalting step, an ion blending step, and a filtering step. The control method as described in claim 7, wherein the deep seawater is seawater located below 200 meters below sea level, the hardness range of the deep seawater is 6,000-7,000 mg/L, and the minimum concentration of silicate is 20 μM. The control method as described in claim 1 further comprises a dilution step, wherein the treated seawater concentrate is diluted to obtain a regulated seawater, wherein the regulated seawater contains a boron ion concentration of less than 0.5 mg/L. A control method as described in claim 9, wherein the regulated seawater contains magnesium ions in a concentration range of 240-300 mg/L.