TWI532684B - Method for obtaining high calcium and magnesium mineral water from deep seawater - Google Patents

Description

Method for obtaining high calcium magnesium mineral water from deep seawater

The invention relates to a method for obtaining high calcium magnesium mineral water from deep seawater, in particular to a method for obtaining high calcium magnesium mineral water from deep seawater by using a reverse osmosis membrane and then using different nanofiltration membrane steps. Methods.

In recent years, deep seawater has become the main focus of the world's development. Through the treatment of deep seawater, rich and clean minerals and trace elements can be extracted, which can be used by modern people to make up for the daily intake of minerals. The reason why deep seawater is rich in minerals is mainly because sunlight cannot penetrate, photosynthesis cannot occur, and inorganic nutrient salts are not consumed by phytoplankton. Compared with surface seawater, deep seawater has a higher content of inorganic nutrient salts. Due to its rich inorganic nutrients, deep seawater is widely used in health drinks, food, pharmaceutical products and aquaculture.

At present, deep seawater can be treated by distillation, reverse osmosis or electrodialysis to obtain pure water, mineral water and low-salt seawater concentrate. The pure water can be used as human drinking water, and mineral water and low-salt seawater concentrate can be used as a source of minerals needed to supplement the human body.

However, the distillation method requires a large volume of equipment and needs to be at a high temperature. In the environment.

The reverse osmosis method filters all the solute and ions in the water indiscriminately, so it is not suitable for selective filtration of ions in the deep seawater, and there is a phenomenon of seawater seepage during the process, which greatly affects the water quality of the desalted water. Suitable for the removal of sodium ions.

The electrodialysis method consumes a large amount of electric energy, and as the resistance caused by the fresh water of the seawater increases, the current intensity cannot be increased to affect the efficiency, and further, when the total dissolved solids contained in the seawater is high, if the electricity is high, When dialysis treatment of seawater, the electricity consumption per ton of water will be higher than the reverse osmosis method, which is not economical. In addition, the use of electrodialysis to obtain high calcium magnesium mineral water takes a long time, and the maximum daily output is 4 tons, and the treatment efficiency is not good.

Furthermore, the reverse osmosis method and the electrodialysis method are methods for separating various minerals or desalinating seawater in seawater through an ion membrane, and the ionic membrane may cause scale, clogging, and deterioration with a long period of use. And it is not easy to produce a variety of minerals with different content ratios.

Therefore, in view of the current market demand trend, it is necessary to develop a method for obtaining mineral water containing high levels of magnesium ions and calcium ions.

Accordingly, it is an object of the present invention to provide a method for obtaining high calcium magnesium mineral water from deep seawater. The method can effectively obtain mineral water with high content of calcium ions and magnesium ions from deep seawater.

Thus, the method for obtaining high calcium magnesium mineral water from deep seawater comprises the following steps: (a) reverse osmosis treatment of a deep seawater using a reverse osmosis membrane to form a reverse osmosis concentrate and a diluent; (b) blocking the use of a first nanofiltration membrane The sulfate ion in the reverse osmosis concentrate passes to form a first filtrate, and a solution of residual sulfate ions; then, (c) blocks the calcium in the first filtrate using a second nanofiltration membrane The ions pass through the magnesium ions to form a second filtrate, and a high calcium magnesium mineral water.

In this step (a), the reverse osmosis membrane functions to reverse osmosis the deep seawater to remove water from the deep seawater, thereby obtaining a high mineral reverse osmosis concentrate. The reverse osmosis membrane can be used as a reverse osmosis membrane which has been subjected to reverse osmosis treatment in deep seawater. The reverse osmosis membrane is, for example but not limited to, the product model BW30-440i (label: Dow) and the like.

In the step (a), preferably, the ratio of the weight of the magnesium ions to the weight of the calcium ions in the reverse osmosis concentrate ranges from 3 to 4.

In this step (a), the apparatus used in the reverse osmosis treatment may employ a reverse osmosis apparatus which has been conventionally applied to deep seawater reverse osmosis treatment.

In this step (a), preferably, the reverse osmosis apparatus has a feed operating pressure ranging from 500 psi to 1,000 psi. Preferably, the feed temperature of the reverse osmosis apparatus ranges from 6 ° C to 7 ° C. Preferably, the reverse osmosis device has a diluent recovery of 20%. The recovery refers to the volume of the diluent divided by the sum of the volume of the reverse osmosis concentrate and the diluent.

In the step (b), the first nanofiltration membrane is used to block the passage of the sulfate ion in the reverse osmosis concentrate because the sulfate ion forms a water-insoluble calcium sulfate with calcium ions in the water and precipitates. In addition, when the high content of sulfate is present in drinking water, in addition to the bitter taste, it also causes diarrhea to be harmful to the human body, so it is necessary to remove the sulfate ion from the reverse osmosis concentrate. At the same time, in order to enable the salt formed by calcium ions to be mainly dissolved in water-soluble calcium chloride for absorption by the human body, it is more necessary to remove the sulfate ion to avoid formation of calcium sulfate which is poorly soluble in water.

The first nanofiltration membrane can pass calcium ions and magnesium ions and can effectively prevent passage of sulfate ions. The first nanofiltration membrane is, for example but not limited to, NF270-4040 (label: Dow), ESNA1-LF2-LD (label: Nitto Denko Hydranautics), or M-N4040A9 (label: Applied membranes).

The first filtrate refers to a solution formed by passing through the first nanofiltration membrane in the reverse osmosis concentrate. The solution of the residual sulfate ion refers to a solution formed by the first nanofiltration membrane in the reverse osmosis concentrate.

In this step (b), the apparatus used to block sulfate ions can be used in equipment used to remove sulfate ions in deep seawater.

In this step (b), preferably, the apparatus is operated at a pressure in the range of 50 psi to 250 psi. Preferably, the first filtrate recovery of the apparatus ranges from 20% to 80%. The recovery refers to the volume of the first filtrate divided by the sum of the volume of the residual sulfate ion solution and the first filtrate.

Preferably, the sulfate ion content ranges from 45 mg to 285 mg based on the total amount of the first filtrate being 1 liter. Preferably, the magnesium ion content ranges from 300 mg to 500 mg, and the calcium ion content ranges from 50 mg to 300 mg, based on the total amount of the first filtrate. Preferably, the sodium ion content ranges from 10,000 mg to 11,500 mg, based on the total amount of the first filtrate.

In the step (c), the second nanofiltration membrane is used for the purpose of achieving a concentration effect and increasing the content of calcium ions and magnesium ions. The execution of the step (c) is not limited to one time, and can be adjusted according to the required content of calcium ions and magnesium ions.

In the step (c), the second nanofiltration membrane can effectively prevent the passage of calcium ions and magnesium ions. The second nanofiltration membrane is for example but not limited to TM610 (label: Toray).

The second filtrate refers to a solution formed in the first filtrate after passing through the second nanofiltration membrane. The high calcium magnesium mineral water refers to a solution formed by the second nanofiltration membrane in the first filtrate.

In this step (c), preferably, the apparatus is operated at a pressure in the range of 50 psi to 250 psi. Preferably, the second filtrate of the apparatus has a recovery ranging from 20% to 80%. The recovery refers to the volume of the second filtrate divided by the sum of the volume of the second filtrate and the high calcium magnesium mineral water.

Preferably, the magnesium ion content ranges from 500 mg to 2,500 mg based on the total amount of the high calcium magnesium mineral water of 1 liter. Preferably, the calcium ion content ranges from 280 mg to 800 mg, based on the total amount of the high calcium magnesium mineral water.

Preferably, the method for obtaining high calcium magnesium mineral water from deep seawater further comprises the step of adding the diluent to the high calcium magnesium mineral water to form a low sodium high calcium magnesium mineral water. Preferably, the sodium ion content is in the range of 30 mg or less based on the total amount of the low sodium high calcium magnesium mineral water.

Preferably, the method of obtaining high calcium magnesium mineral water from the deep seawater further comprises the step of adding the residual sulfate ion solution to the reverse osmosis concentrate.

The method of obtaining high calcium magnesium mineral water from the deep seawater further includes the step of adding the second filtrate to the first filtrate.

The effect of the invention is that the method first obtains a reverse osmosis concentrate having a high concentration of minerals by using a reverse osmosis membrane, and then removes the sulfate ion by using the first nanofiltration membrane to prevent the sulfate ion from reacting with the calcium ion to form an insoluble solution. The content of the calcium ion is reduced, and the second nanofiltration membrane is used to achieve the concentration effect, and the calcium ion and magnesium ion content are increased, and the mineral water with high calcium ion and magnesium ion is effectively obtained from the deep seawater, and then As a source of minerals needed to supplement the body.

<<Example 1>>

Providing a reverse osmosis device, wherein a reverse osmosis membrane (label: Dow; model: BW30-440i) is used for reverse osmosis treatment of deep seawater to form a reverse osmosis concentrate and a diluent, wherein the deep seawater The calcium ion content was 410 mg/L, the magnesium ion content was 1,350 mg/L, the sodium ion content was 11,140 mg/L, and the sulfate ion content was 2,660 mg/L. The reverse osmosis concentrate had a calcium ion content of 511 mg/L, a magnesium ion content of 1,780 mg/L, a sodium ion content of 12,353 mg/L, and a sulfate ion content of 3,111 mg/L. The equipment was operated at a temperature of 6 ° C to 7 ° C and a feed operating pressure of 600 psi.

A first nanofiltration membrane (label: Dow; model: NF270-4040) is used to block the passage of sulfate ions in the reverse osmosis concentrate to form a first filtrate, and a solution of residual sulfate ions. Among them, the equipment has a feed operating pressure of 150 psi. The first filtrate has a calcium ion content of 243 mg/L, a magnesium ion content of 389 mg/L, a sodium ion content of 10,210 mg/L, a sulfate ion content of 48 mg/L, and a recovery rate of the first filtrate. It is 20%.

<<Examples 2 to 3>>

Examples 2 to 3 were the reverse osmosis concentrates prepared in the same manner as in Example 1, except that the recovery rate of the first filtrate was changed as shown in Table 1.

<<Example 1-1>>

Using a second nanofiltration membrane (label: Toray; model: TM610) to block the passage of calcium ions and magnesium ions in the first filtrate to form a second filtrate, and a second residual liquid, wherein the device The feed operation pressure was 150 psi. The second residual liquid had a calcium ion content of 310 mg/L, a magnesium ion content of 540 mg/L, and a sodium ion content of 10,210 mg/L.

Then, the second residual liquid is further treated by the second nanofiltration membrane to obtain high calcium magnesium mineral water, wherein the high calcium magnesium mineral water has a calcium ion content of 340 mg/L and a magnesium ion content. It was 670 mg/L and the sodium ion content was 11,000 mg/L.

Next, the diluent of Example 1 is added to the high calcium magnesium mineral water to form a low sodium high calcium magnesium mineral water, wherein the low sodium high calcium magnesium mineral water has a calcium ion content of 3.5 mg/L and a magnesium ion content. It is 20 mg/L and the sodium ion content is 30 mg/L.

<<Examples 1-2 to 1-3>>

Examples 1-2 to 1-3 were prepared in the same manner as in Example 1-1 to prepare high calcium magnesium mineral water and low sodium high calcium magnesium mineral water, except that the recovery rate of high calcium magnesium mineral water was changed. As shown in table 2.

In summary, the method first obtains a reverse osmosis concentrate having a high concentration of minerals by using a reverse osmosis membrane, and then removes the sulfate ion by using the first nanofiltration membrane to prevent the sulfate ion from reacting with calcium ions to form an insoluble matter. In order to reduce the calcium ion content, and to use the second nanofiltration membrane to achieve the concentration effect, increase the content of calcium ions and magnesium ions, and effectively obtain high-content calcium and magnesium ion mineral water from the deep seawater, and then can be done In order to supplement the source of the minerals required by the human body, it is indeed possible to achieve the object of the present invention.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

Claims (10)

A method for obtaining high calcium magnesium mineral water from deep seawater, comprising the steps of: (a) performing reverse osmosis treatment on a deep seawater using a reverse osmosis membrane to form a reverse osmosis concentrate and a diluent; (b) using a first nanofiltration membrane blocks the passage of sulfate ions in the reverse osmosis concentrate to form a first filtrate, and a solution of residual sulfate ions; and then, (c) uses a second nanofiltration membrane Blocking the passage of calcium ions and magnesium ions in the first filtrate to form a second filtrate, and a high calcium magnesium mineral water. A method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, wherein the ratio of the weight of the magnesium ions to the weight of the calcium ions in the reverse osmosis concentrate ranges from 3 to 8. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, wherein the sulfate ion content ranges from 45 mg to 285 mg based on the total amount of the first filtrate. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, wherein the magnesium ion content ranges from 300 mg to 500 mg, and the total amount of the first filtrate is 1 liter, and The calcium ion content ranges from 50 mg to 300 mg. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, wherein the magnesium ion content ranges from 500 mg to 2,500 mg based on the total amount of the high calcium magnesium mineral water of 1 liter. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, wherein the calcium ion content ranges from 300 mg to 800 mg based on the total amount of the high calcium magnesium mineral water of 1 liter. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, further comprising the step of adding the diluent to the high calcium magnesium mineral water to form a low sodium high calcium magnesium mineral water. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 7, wherein the sodium ion content is in the range of 30 mg or less based on the total amount of the low sodium high calcium magnesium mineral water. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, further comprising the step of adding the residual sulfate ion solution to the reverse osmosis concentrate. The method for obtaining high calcium magnesium mineral water from deep seawater according to claim 1, further comprising the step of adding the second filtrate to the first filtrate.