JP3173916B2 - Water purifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purifier used for home or business use.

[0002]

2. Description of the Related Art A water purification filter of a water purifier usually causes clogging when the filter is used for 3 to 6 months.
It is known that purified water supply capacity is reduced. For this reason, those in which the pore distribution of the hollow fiber filtration membrane is changed to make it difficult to block, and those in which the amount of activated carbon is increased to extend the life are currently sold.

[0003]

The clogging of the water purification filter is caused by the fact that heavy metal ions such as copper ions and iron ions in the tap water form insoluble salts on the activated carbon layer and the hollow fiber filtration membrane surface, thereby causing the tap water to flow. Caused by blockage. Therefore,
There is a demand for the development of a filter that removes salts that block these channels before the activated carbon layer and the hollow fiber filtration membrane. In addition, manganese ions in tap water cannot be removed during the water supply process at a water purification plant using the current rapid filtration method. SUMMARY OF THE INVENTION An object of the present invention is to provide a water purification filter capable of removing heavy metal ions in consideration of the above-mentioned problems relating to a conventional water purification process and a water purification filter. The present invention
It is another object of the present invention to provide a water purification filter that suppresses clogging of an activated carbon layer and a hollow fiber filtration membrane and has a long life.
Furthermore, an object of the present invention is to provide a long-life water purifier in which clogging is suppressed.

[0004]

SUMMARY OF THE INVENTION The water purifier of the present invention comprises:
The water purification filter includes a heavy metal ion removal layer including a ceramic fiber supporting at least one of calcium carbonate and magnesium carbonate. In addition, the water purifier of the present invention includes the water purification filter described above before and after the activated carbon layer. Further, the water purification filter provided in the water purifier of the present invention carries manganese dioxide on ceramic fibers.

[0005]

According to the water purification filter of the present invention, calcium carbonate and magnesium carbonate carried on ceramic fibers adsorb and remove copper ions and iron ions, which are heavy metal ions, and manganese dioxide adsorbs manganese ions.

The present invention has been completed as a result of investigating in detail the cause of clogging of a water purifier filter and variously examining measures for preventing the clogging. A hollow fiber filtration membrane was collected from a water purifier used for about 6 months, and the surface thereof was analyzed. As a result, attachment of a crystalline substance was observed. The components constituting the crystal deposit were mainly copper and iron. Next, when the atomic concentration of tap water was measured, the same copper and iron as those attached to the hollow fiber filtration membrane were measured from tap water. These ions react with dissolved oxygen and carbon dioxide in tap water to form insoluble salts, are captured on the surface of the hollow fiber filtration membrane, cause clogging, and block the filtration membrane, reducing the amount of flowing water. is there. Those which form insoluble salts of copper and iron include copper oxide, cuprous hydroxide, cupric hydroxide, copper carbonate, ferrous carbonate, ferrous hydroxide and ferric hydroxide.

The use of a basic salt can be considered as one that effectively adsorbs copper ions and iron ions in water that form these insoluble salts. In consideration of drinking, the basic salt is preferably a food additive. Among the basic salt food additives, calcium salts and magnesium salts are the most desirable components because they are components that make water delicious. When calcium and magnesium are dissolved in water, it is necessary to adjust the hardness so as not to be too high. Food additives meeting such conditions include calcium carbonate and magnesium carbonate.

In the present invention, the calcium carbonate and the magnesium carbonate are supported on a fibrous inorganic substance, particularly a ceramic fiber. As a supporting method, it is preferable to use the above-described particles of calcium carbonate and magnesium carbonate and ceramic fibers as raw materials to form a paper by a papermaking technique. Since the ceramic fiber is not decomposed by microorganisms like cellulose, it provides a water purification filter that can be used even in an environment where waterborne microorganisms may be present.

Although manganese ions in tap water can hardly be removed in the current water supply process, according to the present invention, manganese ions can be removed by adsorbing manganese ions on manganese dioxide. That is,
When manganese ions in water come into contact with manganese dioxide, they react with dissolved oxygen to form manganese dioxide,
It can be removed by attaching to the originally supported manganese dioxide. As manganese dioxide to be used, any of α-manganese dioxide, β-manganese dioxide and γ-manganese dioxide can be used, but γ-manganese dioxide is the most excellent in terms of adsorption efficiency and persistence of its characteristics.

Next, the insertion position of the filter of the present invention in the water purifier will be described. It is known that heavy metal ions are adsorbed on the activated carbon layer. The adsorbed heavy metal ions grow on the activated carbon and may be desorbed by the influence of dissolved oxygen, carbon dioxide and the like in water. To prevent this, it is necessary to adsorb heavy metal ions before the activated carbon layer. Further, activated carbon for water purifiers has an excellent ability to selectively decompose calcium, so that heavy metal ions are less likely to be adsorbed over a long use period. Therefore, it is good to install in any position of the back part in addition to the front part of the activated carbon layer. The filter of the present invention can support activated carbon in addition to the above-mentioned carbonate and manganese dioxide.

[0011]

Next, embodiments of the present invention will be described. Alumina-silica fiber (length 1 to 10 mm), calcium carbonate (particle diameter: about 3 μm), magnesium carbonate (particle diameter: about 3 μm), and manganese dioxide (particle diameter: about 3 μm) in a weight ratio of 3: 1.5:
The mixture was mixed at a ratio of 0.5: 1 and dispersed in water. Starch was added as a binder to the mixture, and after stirring, aluminum chloride.
A paper obtained by adding and coagulating hexahydrate to obtain a filter was obtained. FIG. 1 schematically shows this paper filter, wherein 1 is a ceramic fiber, 2 is calcium carbonate, magnesium carbonate particles, and 3 is manganese dioxide particles.

The above filter was cut into a circular shape having a diameter of 68 mm, and three pieces (about 3 g in weight) were filled in a water filtration cartridge, and an aqueous solution in which ferric chloride, copper chloride and manganese chloride were dissolved was used as pseudo tap water. The solution was passed at a filtration flow rate of 2 L / min, and the concentration of heavy metal ions in the filtered solution was measured using a transition metal ion measurement device. The results are shown in Table 1. The measurement limit of the transition metal ion concentration measuring device used in the experiment is 10 ppb.

[0013]

[Table 1]

A paper filter was prepared in the same manner as described above, using a mixture of calcium carbonate, magnesium carbonate and manganese dioxide alone and ceramic fibers at a weight ratio of 2: 1. For the filter supporting calcium carbonate or magnesium carbonate, an aqueous solution containing 10 ppm each of copper ions (Cu ²⁺ ) and iron ions (Fe ³⁺ ) is provided. For the filter supporting manganese dioxide, manganese ions (Mn ^{2 +} ) To 1
A test was conducted in which an aqueous solution containing 0 ppm was filtered at 2 liters / minute. As a result, all of the filters were able to remove heavy metal ions below the measurement limit at the initial stage. Further, it was confirmed that after passing 1000 liters of water, copper ions and iron ions were removed by 90% or more, and manganese ions were removed to below the measurement limit.

Next, in the same manner as described above, a paper filter supporting calcium carbonate and magnesium carbonate was filled in a water filtration cartridge, and tap water was flowed at a filtration flow rate of 2 liter / min. , Calcium ion and magnesium ion concentrations were measured. The results are shown in Table 2. Table 2 also shows values of commercially available alkaline ionized water for comparison. The concentration was measured by ion chromatography.

[0016]

[Table 2]

From the above results, it can be seen that even when the amount of water flow increases, the effect of removing heavy metal ions is maintained and calcium ions and magnesium ions can be added.

Next, as a fiber for supporting calcium carbonate or the like, there is also a cellulose or the like, which may be a nutrient source for microorganisms existing in an aqueous system. Therefore, the degradability by microorganisms was examined. River surface water was collected and used as a microbial source. Then, the filter according to the present invention using alumina silica fiber and the filter using nitrocellulose as in the above-mentioned example were added thereto and continuously cultured for 2 months.
Two months later, the strength of each filter was measured, and the filters were observed with a scanning electron microscope. As a result, it was observed that the filter using nitrocellulose was degraded by microorganisms, had a reduced tensile strength, and had a rough surface by a scanning electron microscope. On the other hand, in the filter according to the present invention, both the tensile strength and the surface condition were almost the same as before use. As described above, since the filter of the present invention is hardly decomposed by microorganisms, it was found that it can be used in an environment where water-based microorganisms may be present, such as a water purifier.

[0019]

As described above, according to the present invention, a water purification filter capable of efficiently removing heavy metal ions in water can be obtained. Further, according to the present invention, it is possible to obtain a water purifier in which the activated carbon layer and the hollow fiber filtration membrane hardly cause clogging.

[Brief description of the drawings]

FIG. 1 is a schematic view of a filter according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic fiber 2 Carbonate 3 Manganese dioxide

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kunio Kimura 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-245886 (JP, A) JP-A-49- 39864 (JP, A) JP-A-64-22393 (JP, A) JP-A-1-137721 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 1/28 C02F 1 / 44 B01J 20/00-20/34

Claims (1)

(57) [Claims] 1. An activated carbon layer, a hollow fiber filtration membrane provided downstream thereof, and a heavy metal ion removal layer provided before and after the activated carbon layer, wherein the heavy metal ion removal layer is made of calcium carbonate and magnesium carbonate. A water purifier comprising a ceramic fiber carrying at least one member selected from the group.