JPH0788487A - Water purifying agent - Google Patents

Abstract

PURPOSE:To provide a water purifying agent which is useful in making tasty, healthy water and especially facilitates the elution of calcium. CONSTITUTION:A water purifying agent comprises 99.5-90wt.% of calcium carbonate and 0.5-10wt.% of calcium oxide which is fixed on the surface of the calcium carbonate. To fix calcium oxide on the surface of calcium carbonate, for example, a method is proposed in which calcium hydroxide is mounted on a porous body of calcium carbonate, or particles of calcium carbonate are heated at 650-750 deg.C. By the use of the water purifying agent, an odor of chlorine or chlorinated lime in city water can be eliminated, and the continuous elution of desired concentration of calcium can be attained into drinking water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purifying agent, and more particularly to a water purifying agent for tap water used for various water purifiers used for producing delicious water, and more particularly to a calcium eluent.

[0002]

2. Description of the Related Art Chlorine compounds such as chlorine and chlorine are used for disinfecting and sterilizing tap water. In recent years, the water quality of water sources has deteriorated due to environmental pollution, and it has become difficult to secure high quality raw water. Therefore, the amount of chlorine contained in tap water tends to gradually increase. Therefore, it has a strong chlorine and chlorine odor and is not tasty. According to the “Delicious Water Quality Requirements” of the Ministry of Health and Welfare Tasty Water Study Group, the residual chlorine is 0.4 mg / 1 or less. In addition, there is a golden odor due to rust on the piping.

[0003] In order to remove these odor and mold odor, conventionally, inorganic materials such as various zeolites, activated carbon, coral stone, barite stone, and coral sand have been mainly used. Also, many combinations with various polymers and organic materials such as ascorbic acid, sugars, amino acids, nucleotides and their derivatives have been proposed.

On the other hand, alkaline drinking water containing a large amount of calcium ions is known as healthy drinking water. As a method for producing alkaline drinking water containing a large amount of calcium, for example, there is a method using electrolysis and a calcium eluent. In the method using electrolysis, two positive and negative electrolytic chambers are faced to each other with a porous partition wall interposed therebetween, and raw water is allowed to flow into each electrolytic chamber, and at the same time, between the positive and negative electrodes provided in each electrolytic chamber. By applying a DC voltage and electrolyzing the raw water, alkaline ionized water containing a large amount of calcium, sodium, potassium, etc. is obtained from the cathode chamber. At this time, calcium lactate, calcium glycerophosphate, calcium sulfite, etc. are added in order to obtain alkaline ionized water rich in calcium. The acidic water obtained from the anode chamber is used for bathing, washing the face, etc.

In addition, natural calcium carbonate such as coral sand and limestone is used for the method using a calcium eluent. For example, Japanese Patent Publication No. 3-12953 proposes a water quality improving material obtained by heating and activating sandy coral or coral sand. According to the specification, sandy corals or coral sands are activated by heating at 200 ° C to 450 ° C to neutralize the hydrochloric acid content in tap water. It has been shown to supply. CaCO ₃ + 2HCl → Ca ²⁺ + 2Cl ⁻ + CO ₂ ↑
+ H ₂ O

However, in such a method, although acidic water can be neutralized, if the water is not so strongly acidic, the calcium content will not be supplemented or an extremely long contact time will be required. To do.

As described above, the conventionally known method is relatively expensive, cannot withstand continuous use for a long period of time, or cannot be easily moved, and further, the desired calcium content can be obtained. However, there is a drawback in that the water is not sufficiently supplied, and a water purifying agent which is more satisfactory, particularly a water purifying agent for the purpose of supplementing calcium, has been desired.

[0008]

[Problems to be Solved by the Invention] In order to obtain delicious and healthy drinking water, various measures are necessary. A mineral balance is required, such as removal of chlorine and chlorine odors, removal of musty odors and raw odors, intake of minerals that are beneficial to health and longevity, and removal of non-beneficial mineral components. Regarding the problem of mineral balance, for example,
Hashimoto et al. [Water Treatment Technology, Vol 29 (NO.1) 13-
28 (1988)] shows the index of healthy water as K _index =
Ca-0.87Na> 5.2, O _index = (C
a + K + SiO ₂ ) / (Mg + SO ₄ > 2.0,
I suggest it as a guide. That is, drinking water with a high calcium content and a low sodium content is good for longevity. There seems to be no indication that too much calcium is harmful to health.

A solution to these problems is to select a filter material mineral, other adsorbent, or a filter material according to the water quality in each region. For example, limestone filter can be used for calcium-deficient water, and igneous rock filter can be used for silica-deficient water.

However, it is practically impossible for general consumers to constantly inspect the water quality and use the water that has been treated accordingly. Therefore, a simple means for obtaining delicious water is to supplement the calcium content, and further to remove the chlorine content and other odorous impurities. In addition, it is also preferable to reduce the content of alkali metals in order to obtain healthy water.

The above-mentioned calcium carbonate is used as a substance that elutes calcium, but the solubility of calcium carbonate is extremely small, and it is only 13 ppm at 25 ° C.
(As calcium oxide). The solubility of calcium sulfate is large at about 0.2 wt% at 25 ° C, but
_As you can see from the _index , sulphate not only makes water taste bad, but it is also bad for your health. Also, the solubility of calcium oxide or calcium hydroxide is 0.11w at 25 ° C.
It dissolves relatively well with t% (as calcium oxide). However, it dissolves too much and its pH becomes too high to be used as a water purifier for water purifiers for tap water. Therefore, it is necessary to arbitrarily adjust the elution of calcium oxide. Calcium concentration is about 5 to 500 μg / ml (about 5 to 500 ppm), especially 10 to 100 μg / ml, and further 40 to 100
It is preferably present in μg / ml.

Further, in general, when it is intended to be used as drinking water or the like, it is important to reach a desired calcium concentration in a relatively short time and to maintain it at a constant level.

[0013]

The present invention has been made in view of the above, and relates to a water purification agent in which calcium is easily eluted in order to provide delicious and healthy water. Not only does it make it easier to elute calcium,
The present invention relates to a water purification agent that can be used for a long period of time (for example, half a year to one year). As a result of earnest research to obtain a water purifier having such performance, calcium carbonate 99.5 to 90% by weight and calcium oxide 0.5 to 1
The present invention has been completed by finding a water-purifying agent containing 0% by weight and having calcium oxide adhered to the surface of calcium carbonate.

Here, the state in which calcium oxide is adhered to the surface of calcium carbonate means, for example, that calcium oxide exists in a state of being sandwiched between crystals of the surface layer portion of calcium carbonate, or both crystals partially form a mixed crystal. In this case, some kind of chemical or physical bond is formed between the two, which is different from the state in which the powder and granules are simply mixed. That is, when both are simply mixed and in a state where sieving or the like is possible, the reason cannot be understood but it cannot be continuously used for a long time.

As an example of the means for forming the fixed state of both in the present invention, a water-purifying agent composed of 99.5 to 90% by weight of calcium carbonate and 0.5 to 10% by weight of calcium oxide is used on the surface of the calcium carbonate powder. Calcium oxide is 0.
It may be supported in an amount of 5 to 10% by weight (based on the total weight). Such a water purifying agent can be obtained by impregnating a calcium carbonate porous body with calcium hydroxide and then drying. In this case, as a raw material for calcium hydroxide,
It is preferable to use calcium oxide obtained by baking recognized shellfish and egg shells as food additives. As another preferable method, calcium carbonate powder is
It is a method of burning at a temperature of 0 to 750 ° C. within a range in which the loss on ignition is 0.5 to 5% by weight. That is, FIG. 1 shows the burning temperature in the case of using coral sand and the treated product 1 g.
Is an example in which 100 g of water was suspended and the pH was measured over time. In FIG. 1, untreated (a), 500 ° C.
(B), 600 ° C (c), 650 ° C (d), 750 ° C
(E) and cauterization heat treatment at each temperature of 850 ° C. (f) are shown.

As can be seen from FIG. 1, the higher the treatment temperature, the higher the pH value of water, but the effect of time is small. Also, if the pH is too high to exceed 12, it is not preferable as delicious water.

Therefore, the burning temperature should be 650 to 750 ° C. Furthermore, the treatment time rises rapidly at the beginning of the treatment, but is not always constant depending on the temperature. Therefore, it is preferable to set the ignition loss as a reference, and it is important to set the ignition loss range of 0.5 to 5% by weight. In other words, at 650 ° C. or lower, the loss on ignition is too small, and the elution amount and elution rate of calcium do not significantly increase. Also, 7
At 50 ° C or higher, the elution amount and elution rate of calcium are too large to be continuously usable for a long time. The means for forming the fixed state of the present invention is not limited to the above preferable method.

Calcium carbonate that can be used as a raw material is divided into chemically synthesized products and non-chemically synthesized products.
The former is light calcium carbonate and heavy calcium carbonate,
The latter includes coral sand, shells and limestone. Of these, coral sand is preferred because it contains minerals such as magnesium, silica, potassium and iron. In addition, as calcium compounds other than calcium carbonate, calcium sulfate, dolomite (CaCO ₃ .MgC
O ₃ ), calcium phosphate, calcium silicate, etc., but they are not always preferable as a water purifying agent except calcium silicate. Calcium sulfate makes sulfate roots and dolomite make magnesium bad taste, and calcium phosphate may dissolve phosphorus as calcium elutes.

The proportion of calcium oxide strongly bound to calcium carbonate is preferably 99.5 to 90% by weight of calcium carbonate and 0.5 to 10% by weight of calcium oxide. When the amount of calcium oxide is 0.5% by weight or less, the elution of calcium is insufficient and the effect is not remarkable. Further, when the calcium oxide content is 10% by weight or more, depending on the amount of the water purifying agent used for a given drinking water or the water passing amount for a given amount of the water purifying agent, the pH becomes too high, and The amount of elution is too large to continuously use. Therefore, it is necessary to change the binding ratio of calcium oxide depending on the purpose of use and the form of use.

The particles of calcium carbonate are generally BET.
The specific surface area by law 0.05~50m ² / g, is preferably employed of about 0.1 to 15 m ² / g. If the specific surface area is too small, the layer of calcium oxide to be present on the surface will be thick, and it will be difficult to obtain sufficient adhesion strength.If the specific surface area is too large, the particle size will generally be too small and it will be inconvenient to handle. However, there is a case where the initial elution amount of calcium oxide increases too much, which is not preferable.

The water purifier of the present invention can be used alone. However, as a general usage form, it is desirable to use it in combination with other materials depending on the purpose of use. For example, when chlorine and chloromethane are to be removed and calcium is desired to be added, the combined use with activated carbon is preferable. In addition, if you want to remove calcium odor and musty odor and add calcium, use with inorganic materials such as zeolite, coral stone, barite stone and organic materials such as ascorbic acid, sugar, amino acids, nucleotides and their derivatives. Is preferred. Furthermore, once high-purity water is produced using a reverse osmosis membrane or an ion exchange resin, calcium and other mineral components can be added using coral sand or the water purifying agent of the present invention. It is extremely useful in producing good water. Also,
When the water purifier of the present invention is used together with water after chlorine removal by using activated carbon, a hollow fiber membrane is used in combination for sterilization, or an antibacterial agent such as silver is used in combination to suppress the generation of bacteria. Are both valid.

The water purification agent of the present invention can be used by filling it into a water purifier attached to a tap water tap. Further, the water purifying agent of the present invention can be put into a water-permeable packaging material to form a pack, which can be put into drinking water, tea, miso soup and other foods and drinks for use. It can also be used for manufacturing processed drinks and foods.

In the following examples, the amount of dissolved calcium as one of the performance evaluations of the water purifying agent was determined by the following method. Weigh 1.0 g of sample into a beaker and add 500 ml of ultrapure water. Add a Teflon stirrer piece and stir for 1 hour. After standing, take 1 ml of the supernatant and
The volume was adjusted to 00 ml. This was introduced into ICP (inductively coupled plasma) to quantify calcium. ICP emission spectrometer: SPS150 manufactured by Seiko Denshi Kogyo
0VR Ar gas flow rate Plasma: 161 / min Sample: 0.351 / min Auxiliary: 0.71 / min Measurement wavelength: Ca 393, 366 nm Photometric height: 12 mm (on load coil) Plasma output: 1.3 kW

Example 1 Examples will be shown below for specifically illustrating the present invention, but the present invention is not limited to these examples.

Granular coral sand manufactured by Marine Bio Co. is previously baked at 400 ° C. for 2 hours. This had a BET surface area of 0.2 m ² / g. 20 g of this is accurately weighed and transferred to an alumina crucible having an inner volume of 100 ml. The temperature was raised at a rate of 10 ° C./min in a commercially available electric furnace, and firing was performed at 700 ° C. for 2 hours. The weight after cooling was 18.56 g,
The BET surface area was 0.5 m ² / g. The weight loss at this time was 7.2%. Considering that this was due to the generation of carbon dioxide gas, the generated calcium oxide was 9, 2% by weight.
It can be calculated as (7.2 × 56/44). As a result of X-ray diffraction of the sample, a diffraction image of calcium oxide was confirmed in addition to calcium carbonate (this is referred to as sample A).

The amount of calcium eluted from the sample into water was measured by an ICP emission spectrometer, and as a result, 75 μg of calcium was eluted in 1 ml of water. As a result of measuring the calcium elution amount from the coral sand before firing under exactly the same conditions,
It was 4.7 μg. On the other hand, 10 pieces of granular coral sand
It was 840 μg in the sample calcined at 00 ° C. for 8 hours (this is referred to as sample B). From these facts, in 75 μg of sample A, the amount of calcium estimated to be eluted from the calcium oxide produced by calcination is considered to be (75-4.7 = 70.3) μg, and in sample B, This means that 835.3 μg was increased by firing.

5 g of each sample of A and B was placed in 11 waters, and the water was refreshed once a day. There was still 73 μg / ml calcium in the water of sample A after 3 months, but for sample B it was 4.7 μg / ml.

Examples 2 to 7 In the same manner as in Example 1, various firing temperatures were used to deposit calcium oxide on the granular calcium carbonate. The results are shown in Table 1 (calcination time is all 2 hours).

[0029]

[Table 1]

The specific surface areas of the granules obtained in Examples 2, 3 and 7 were 0.3, 0.4 and 0.5 m ² / g, respectively, and the higher the temperature, the higher the specific surface area. became. Such a phenomenon cannot be recognized by simply blending calcium carbonate and calcium oxide.

Comparative Example 1 Calcination temperature was set to 850 ° C. in the same manner as in Example 1 to deposit calcium oxide on granular calcium carbonate.
At this time, the weight loss was 74% and the amount of CaO produced was 94% by weight. The initial Ca elution amount was 640 μg / ml.

0.5 g of the obtained granular material was put into 200 ml of water and stirred for 30 minutes. The pH of the water at this time is 12.
It was 2. As the high pH shows, most of the calcium carbonate is converted to calcium oxide, and the solubility of calcium oxide at 20 ° C. is 0.118 g-CaO / 10.
Since it is 0 g-H ₂ O, calcium is gradually eluted. Therefore, theoretically, calcium oxide cannot be used as a water purifying agent.

Example 8 Using 20 g of calcium carbonate (trade name: Corocalco T, specific surface area: 5.5 m ² / g) for food additives manufactured by Shiraishi Calcium Co., similar to Example 1, baked at 700 ° C. for 2 hours. did. The weight after cooling is 18,6 and the weight loss at this time is 7.0.
%Met. Therefore, calcium oxide is 8.9%.
As a result of measuring the amount of calcium eluted into the water of the sample with an ICP spectroscopic analyzer, 84 μg of calcium was eluted in 1 ml of water.

The calcium elution amount after three months was 81 μg, which was determined by the same method as in Example 1.

Example 9 0.4 g of calcined calcium oxide in shell made by N Corp. was weighed and transferred to a beaker having an internal capacity of 300 ml. Add 250 ml of water to this and stir well.
20 g of granular coral sand (surface area 0.2 m ² / g) manufactured by Marine Bio Co., Ltd. is added to a part of the cloudy state.
The water was evaporated by heating while mixing with a glass rod. On the way, it was transferred to an alumina crucible and dried overnight at 200 ° C.

The amount of calcium eluted into the water of the obtained sample was measured by an ICP spectroscopic analyzer. As a result, 1 ml of water contained 14 μg of calcium.

The calcium elution amount after 3 months, which was determined by the same method as in Example 1, was 13 μg.

Example 10 Granular coral sand manufactured by Marine Bio Co. was preliminarily heated to 400 ° C.
Bake for 2 hours. This has a BET surface area of 0.2 m ^2.
/ G. Accurately weigh 700 g of this and transfer to an alumina crucible. The temperature was raised at a rate of 10 ° C./min in a commercially available electric furnace, and firing was performed at 670 ° C. for 2 hours. The weight after cooling was 651.7 g, and the BET surface area was 0.5 m ² / g.
Met. The weight loss at this time was 6.9%, and the calcium oxide produced could be calculated to be 8.7% by weight (6.9 × 56/44). The calcium elution amount of the obtained water purifier is 15
μg / ml H ₂ O. 600g of which is 1 in diameter
It was filled in a 0 cm tubular water purifier. At the time of filling, 700 g of granular activated carbon manufactured by Takeda Pharmaceutical Co., Ltd. was filled in the lower part, and the water purifying agent was filled in the upper part. Filters were placed and fixed between the activated carbon and the water purification agent, and at the top and bottom.

Raw water (tap water) was supplied from the lower part, and drinking water was obtained from the upper part. Sampling was performed after flowing water for about 24 hours with the amount of water used at home (about 31 / min).
Table 2 shows the water quality of raw water and treated water.

[0040]

[Table 2]

As is clear from the results of Table 2, K of raw water
_Index = Ca−0.87Na = 0.9, which is less than 5.2 and can be said to be unhealthy water. Also, O
_index = (Ca + K + SiO ₂ ) / (MgO + SO
₄ ) = 1.5, which is less than 2 and tastes bad. On the other hand, the treated water K _index = Ca-
0.87Na = 12.8, and O _index =
Since it was 2.3, healthy water and delicious water could be obtained.

Table 3 shows changes in the water quality of the treated water after continuous use.

[0043]

[Table 3]

As is clear from the results shown in Table 3, the quality of the treated water is stable and sustainable even after continuous use for 3 months.

EFFECTS OF THE INVENTION The water purifying agent of the present invention strongly binds calcium oxide onto calcium carbonate to remove chlorine odors, chlorine odors, etc. contained in tap water, and to keep desired amount of calcium. Can be dissolved in drinking water. When natural coral sand or limestone is used as the calcium carbonate, not only calcium but also minerals can be eluted, and delicious and healthy water can be obtained.

[0045]

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the firing temperature of coral sand and the pH value of water using the same.

[Explanation of symbols]

(A) to (f) are different firing temperatures, (a) is untreated, (b) is 500 ° C., (c) is 600 ° C., and (d) is 6
50 ° C., (e) represents 750 ° C., and (f) represents 850 ° C., respectively.

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[Procedure amendment]

[Submission date] May 9, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

Claims (5)

[Claims] 1. A water purifier comprising 99.5 to 90% by weight of calcium carbonate and 0.5 to 10% by weight of calcium oxide, and the calcium oxide is fixed on the surface of calcium carbonate. 2. The purified water according to claim 1, wherein 0.5 to 10% by weight (based on the total weight) of calcium oxide is supported on the surface of the calcium carbonate powder. Agent 3. Calcium carbonate powder granules from 650 ° C. to 7
A method for producing a water-purifying agent, which comprises heat-treating at a temperature of 50 ° C. and in a range of 0.5 to 5% by weight of a burning material 4. Calcium carbonate 99. is obtained by impregnating an aqueous solution of calcium hydroxide into a porous calcium carbonate body having a specific surface area of 0.1 to 15 m ² / g and then drying.
Method for producing water purification agent containing 5 to 90% by weight and calcium oxide 0.5 to 10% by weight 5. A method for producing a water purification agent according to claim 4, characterized in that calcium hydroxide prepared from calcium oxide obtained by baking shell and egg shell is used.