JPH07204628A - Water purifier - Google Patents

Abstract

PURPOSE:To remove dissolved ionic harmful substances by filtering water by activated carbon, a cation-exchange resin, and activated carbon successively in this order from water injection side in a first water-purifying tank. CONSTITUTION:From a primary side, a resin frame 9 to which a nylon mesh is stuck is put in a first water purifying tank 2, the tank is then filled with activated carbon 8, and a resin frame 7 produced in the same way as the resin frame 9 is so inserted as to prevent a cation-exchange resin 6 with which the tank 2 is to be filled in the next stage and the activated carbon 8 in the water injection side from being mixed each other. On the frame 7, the cation-exchange resin 6 is put and furthermore a resin frame 5 produced in the same way as the resin frame 7 or the resin frame 9 is so inserted as to prevent the cation- exchange resin 6 and activated carbon 4 to be put in the water coming out side from being mixed each other. On the frame 5, activated carbon 4 is put and a resin frame 3 produced in the same way is so inserted as to prevent the activated carbon 4 from flowing out, and tap water is filtered. Consequently, dissolved ionic harmful substances can be removed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water purifier for obtaining safe and delicious water. More specifically, the present invention relates to a water purifier capable of removing a compound that causes a loss of safety and deliciousness by specifying an adsorbent and its order.

[0002]

2. Description of the Related Art Activated carbon water purifiers whose main purpose is to remove residual chlorine contained in tap water were released and used several years ago, but according to a survey by the Ministry of Health and Welfare, activated carbon water It was clarified that bacteria were not generated, which was not preferable. In order to suppress the outflow of these bacteria, a water purifier that uses membrane filtration such as a porous hollow fiber membrane has been put on the market, and recently this type has become the mainstream.

Recently, there has been proposed a cassette type water purifier in which an activated carbon storage unit and a separation filtration membrane storage unit are further combined with an ion exchange resin storage unit (Actual Kaihei 3-79).
No. 89). Water purifiers using reverse osmosis membranes and water purifiers using natural stones, ceramics, etc. as filter media are also on the market, although the quantity is not large yet.

[0004]

Problems to be Solved by the Invention In the above-mentioned water purifier, which is not subjected to membrane filtration with a porous hollow fiber membrane or the like, various bacteria will propagate and the initial flow of tap water will occur unless it is used for a long time. There was a problem that it would be leaked. In order to solve these problems, a water purifier that performs microfiltration with a porous hollow fiber membrane or a flat membrane and a water purifier with antibacterial properties by methods such as impregnating activated carbon with silver were developed and put on the market. It started to come.

[0005] Activated carbon impregnated with silver has different antibacterial properties depending on the amount of eluted silver, and if a large amount of silver flows out, it is not good for the human body. The method by membrane filtration has sufficient performance to remove various bacteria and the like if there is no mistake in the method of use and fixation of the membrane. If you are using activated carbon, depending on the amount used and performance, trihalomethane dissolved in a trace amount,
It is possible to remove dangerous organic substances such as pesticides.

However, it is difficult to remove cations of heavy metals such as lead and anions such as nitrate nitrogen and nitrite nitrogen, which are soluble, by activated carbon or membrane filtration. there were. A water purifier using a reverse osmosis membrane has been developed to remove these ions, but it removes all minerals, making the water tasteless, and there is a problem in terms of safe and delicious water.

Further, as a water purifier used for a water source containing various kinds of impurities, there has been proposed a water purifier in which tap water is flowed in the order of a filter, an activated carbon, and an ion exchange resin, which are housed in a pressure resistant container (Japanese Patent Laid-Open No. 61-61). No. 257,282).
In the above-mentioned water purifier, even if the adsorption limit of the filter is reached, it is difficult to judge the quality of water unless there is an extreme change in taste, smell, color or the like. The present inventors have arrived at the present invention as a result of studies to obtain safe and delicious water in view of such a situation.

[0008]

The gist of the present invention is a water purifier comprising a first water purification tank comprising a cation exchange resin and activated carbon and a second water purification tank comprising a porous hollow fiber membrane. The water purifier No. 1 is a water purifier characterized in that activated carbon, cation exchange resin, and activated carbon are filtered in this order from the water inlet side.

The present invention essentially comprises a cation exchange resin, activated carbon and a porous hollow fiber membrane. If only cation-exchange resin and activated carbon are used, as described above, when germs are generated, germs flow out into the initial stream from the water purifier, which is not preferable in terms of safety. There is a problem that it is difficult to remove soluble cations of heavy metals such as lead with only activated carbon and porous hollow fiber membranes.

Further, when only the cation exchange resin and the porous hollow fiber membrane are used, trihalomethane, pesticides and the like cannot be adsorbed and residual chlorine cannot be sufficiently removed, which is not preferable.
Among the cation exchange resin, activated carbon and porous hollow fiber membrane of the present invention, the porous hollow fiber membrane in the second water purification tank needs to be present in the final stage of the water purifier.

The cation exchange resin and the activated carbon in the first water purification tank must be filled in the order of activated carbon, cation exchange resin and activated carbon. When the cation exchange resin is placed on the water inlet side of the first water purification tank, the ion exchange resin is oxidatively decomposed due to the chlorine added as a bactericide to the tap water for filtering, and the outflow water is colored. It may cause odor or smell, which is not preferable.

When the activated carbon is on the water inlet side of the first water purification tank and the ion exchange resin is on the water outlet side of the first water purification tank, decomposed products and low molecular weight compounds contained in the ion exchange resin flow out. Since it flows out from the main body of the water purifier, the outflow water may be colored or may have an odor, which is not preferable.

The water purifier of the present invention removes chlorine which promotes oxidative decomposition of the ion exchange resin by the activated carbon on the water inlet side of the first water purification tank, and the activated carbon on the water outlet side which is included in the ion exchange resin. Since the decomposed products and low molecular weight compounds are adsorbed and removed, the water flowing out from the water purifier is colored and odor removed, and extremely delicious water is obtained.

The cation exchange resin used in the present invention may be either a strongly acidic cation exchange resin or a weakly acidic cation exchange resin as long as it corresponds to the substance to be removed. When actually used for tap water, there are many heavy metal cations such as lead that are likely to be eluted as a harmful substance from the lead pipe used for the water distribution pipe and dissolved as a neutral salt. Since it has high properties, it is preferable to use a strongly acidic cation exchange resin capable of decomposing and adsorbing a neutral salt.

The strongly acidic cation exchange resin is generally sold as a sodium salt, but it is not so preferable because sodium may flow out by ion exchange and when it is used for drinking, problems such as an increase in blood pressure may occur. If an acid-type strongly acidic cation exchange resin is used in order to prevent sodium from flowing out, the pH of the effluent becomes 4 or less, which falls outside the standard of tap water quality and becomes more irritating, which is not preferable.

When a strong acid cation exchange resin is used,
It is preferable to use the calcium salt type because the eluted ions improve the taste of water and supplement the calcium which is apt to be lacking in Japanese in terms of health. Thus, in order to drink tap water safely and tasting deliciously, it is most preferable to use a calcium salt type strongly acidic cation exchange resin as the cation exchange resin.

The activated carbon used in the present invention is not particularly limited as long as it has the ability to reduce residual chlorine and the ability to adsorb harmful substances such as trihalomethane and pesticides. Activated carbon such as fibrous or formed carbon can be used. The raw material is not particularly limited, and natural product type activated carbon such as coconut shell activated carbon, bone charcoal, charcoal type, pitch type, petroleum coke type, synthetic activated carbon such as firing activated carbon such as resin or rubber is used. it can. The activation method is also not particularly limited, and activation methods such as steam activation and chemical activation are used.

[0018] When used as a water purifier, the water passing through the activated carbon has a very high passage speed as compared with ordinary activated carbon, so that it is preferable that the bulk density is large. It is preferable that the loss is small. Most of the adsorbed substances have a relatively small molecular weight, and in view of cost, steam activated granular coconut husk activated carbon is most preferable at present.

The activated carbon used on the water inlet side and the water outlet side used in the first water purification tank may be of the same kind or of different kinds, but it is preferable to use activated carbon mainly corresponding to the substance to be adsorbed and removed. The activated carbon of the present invention may be impregnated with a heavy metal such as silver in order to impart antibacterial properties, but it is not preferable that a large amount of heavy metal is eluted. Those having antibacterial properties are relatively preferably used.

In the present invention, a porous hollow fiber membrane is used. The use of a porous flat membrane is not preferable because a sufficient filtration membrane area may not be obtained. The porous hollow fiber membrane of the present invention is not particularly limited as long as minute substances such as bacteria can be removed, and a polyolefin hollow fiber membrane such as polyethylene and polypropylene, or a polysulfone hollow fiber membrane is used.

These porous hollow fiber membranes are used, for example, in order to improve water permeability, ethylene-vinyl acetate copolymer (=
It is preferably hydrophilized with (ethylene-vinyl alcohol copolymer) or the like. The present invention has a form in which a first water purification tank made of a cation exchange resin and activated carbon and a second water purification tank made of a porous hollow fiber membrane are combined, and the outflow water of the first water purification tank is the second one. It will flow into the water purification tank.

In the present invention, it is preferable to provide a flow sensor or a constant flow valve and a pressure switch between the first water purification tank and the second water purification tank. The life of the filter body can be grasped by detecting the life of the filter body by the integrated operating flow time of the pressure switch capable of detecting the integrated filtration flow rate of the flow rate sensor or the constant flow rate.

When the above-mentioned detection means is arranged on the primary side of the first water purification tank, there is a pressure loss of the cation exchange resin, activated carbon and pressure loss of the porous hollow fiber membrane, so that sufficient detection cannot be performed. It is not preferable because It is preferable to dispose it on the secondary side of the second water purification tank, but it is not preferable to make a portion where water easily stays after passing through the porous hollow fiber membrane in terms of generation of various bacteria. Therefore, although there is a pressure loss due to the porous hollow fiber membrane, it is preferable to dispose the porous hollow fiber membrane between the first water purification tank and the second water purification tank.

The signal from the flow rate sensor or the pressure switch of the present invention has means for informing the control unit and the display unit of the life of the water purifier, which is notified by turning on light or voice. In addition to the cation exchange resin, activated carbon and porous hollow fiber membrane of the present invention, a primary filter, ceramics, natural stone, etc. may be used at the same time.

As shown in FIG. 1, tap water has a water inlet (1
Water from 0), the activated carbon (8) on the inlet side in the first water purification tank (2), the cation exchange resin (6), the activated carbon on the outlet side (4)
Through the flow rate sensor (13) in the water pipe, and the second water purification tank (1) containing the porous hollow fiber membrane (12).
After entering 1) and being filtered through the porous hollow fiber membrane (12),
It flows out from the clean water outlet (15).

[0026]

The present invention will be described in detail with reference to the following examples. Example 1 A sectional view of an example of an example of the present invention is shown in FIG. A second clean water tank (2) containing a cation exchange resin (6) sandwiched between activated water (8) on the water inlet side and activated carbon (4) on the water outlet side, and a second hollow space containing a porous hollow fiber membrane (12). The water purification tank (11) is connected by a water pipe and is stored in the outer container (1).

A hydrophilic polyethylene porous hollow fiber membrane (12) was fixed to the second water purification tank (11) with a two-component polyurethane resin, and one end was cut and opened. In the first water purification tank (2), a resin frame (9) with a nylon mesh of 150 mesh attached is installed from the primary side,
150 g of activated carbon (8) was charged, and then a resin frame (7) prepared in the same manner as the resin frame was inserted so that the cation exchange resin (6) to be charged next and the activated carbon (8) on the water inlet side were not mixed.

On top of that, 300 of cation exchange resin (6) was added.
ml filled. Further, a resin frame (5) prepared in the same manner as the resin frame was inserted so that the cation exchange resin (6) and the activated carbon (4) on the water outlet side were not mixed. Activated carbon (4) 3 on it
00 g was filled, and a resin frame (3) prepared in the same manner was inserted so that activated carbon did not flow out.

The first water purification tank (2) and the second water purification tank (1
1) was connected by a water pipe, and an impeller-type flow sensor (13) was provided in the middle of the water pipe. Flow sensor (13)
The output signal is displayed and the control unit (14) integrates the flow rate to display the life of the water purifier.

As the cation exchange resin (6), strong acid cation exchange resin Amberlite IR manufactured by Organo Corporation is used.
Calcium salt type of -120B was used by the following method. Commercially available Amberlite IR-120B was placed in a 1 liter glass funnel, and 1.5 liter of 4N hydrochloric acid aqueous solution (about 3 times equivalent amount of resin exchange capacity, the number of equivalents in parentheses below is the exchange capacity of counterion exchange resin) was 200 ml / min. After passing water at a water-flowing rate of 10 l, and then washing with 10 l of ion-exchanged water at a water-flowing rate of 200 ml / min, 3N sodium hydroxide aqueous solution
1 (about 3 times equivalent) was flown at a rate of 200 ml / min to give a sodium salt form.

Further, it was washed with 10 liters of ion-exchanged water at a water flow rate of 200 ml / min, 1.5 liters of a 4N hydrochloric acid aqueous solution (about 3 times equivalent), and then washed with 10 liters of ion-exchanged water. To the obtained acid-type strongly acidic cation exchange resin, 1 liter of a 3 mol / l calcium chloride aqueous solution (about 3 times equivalent) was passed at a water flow rate of 100 ml / min. After that, ion-exchanged water 10l is 200m
It was washed with water at a rate of 1 / min.

The calcium chloride solution and all of the effluent during the passage of ion-exchanged water were collected, and the calcium ion concentration was measured by the chelate titration method (based on the water purification test method). When the amount of calcium present was back calculated, it was found that 1.92 equivalents / l-ion exchange resin had been exchanged. Activated carbon is Kuraray Coal T made by Kuraray Chemical Co.
-SB48 / 100 was used as it was on the market.

The test results of the water purifier thus obtained are shown below. In the test, the water flow rate was set to 4 l / min. The cartridge life was set at the time when the integrated flow rate of the signal obtained from the flow rate sensor was 8 m ³ .

(1) Residual chlorine removal capacity 2.0 ± 0.2 ppm Residual chlorine-containing water was passed through, and the residual chlorine concentration of the outflow water was measured. The residual chlorine was measured by the o-tolidine method. The residual chlorine concentration in the outflow water after passing 8 m ³ was 0.01 ppm or less.

(2) Sterilizing ability Pseudomonas diminuta IFO 142131.7 × 10 ⁷ pieces / m
Although 6 l of water containing 1 was passed, the number of bacteria in the runoff was 0 / m
It was l.

(3) Lead removal capacity A lead chloride aqueous solution prepared to have a lead concentration of 150 ppb was passed through. The lead concentration in the outflow water after passing 8 m ³ was 10 ppb or less.

(4) Trihalomethane Removal Ability A solution prepared by adjusting chloroform to 60 ppb was passed through.
The chloroform concentration in the effluent during the passage of 8 m ³ of water was 5 ppb or less.

(5) Cartridge life display When the cartridge life display of this apparatus was confirmed using a commercially available integrating flow meter, it was 8012 liters.

[0039]

INDUSTRIAL APPLICABILITY The present invention is a novel water purifier composed of activated carbon, cation exchange resin, activated carbon and porous hollow fiber membrane, which is compact while having sufficient adsorption performance by using a large amount of activated carbon. A revolutionary water purifier equipped with a cartridge life detector that can remove dissolved ionic toxic substances that have been difficult to remove until now, and prevents unpleasant drinking even if toxic substances flow out. is there.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a water purifier of the present invention.

[Explanation of sign]

 1 Water Purifier Outer Container 2 First Water Purification Tank 3 5 7 9 Resin Frame 4 Outflow Side Activated Carbon 6 Cation Exchange Resin 8 Inlet Side Activated Carbon 10 Tap Water Inlet 11 Second Water Purification Tank 12 Porous Hollow Fiber Membrane 13 Flow Rate Sensor 14 Display and control unit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masahiko Taneike 2-3-19 Kyobashi, Chuo-ku, Tokyo Inside Mitsubishi Rayon Co., Ltd.

Claims (3)

[Claims] 1. A first method comprising a cation exchange resin and activated carbon.
In the water purifier consisting of the water purification tank of No. 2 and the second water purification tank made of porous hollow fiber membrane, the first water purification tank is activated carbon from the water inlet side,
A water purifier characterized by being filtered in order of cation exchange resin and activated carbon. 2. A flow sensor or a constant flow valve and a pressure switch are provided between the first water purification tank and the second water purification tank.
Water purifier as described. 3. The water purifier according to claim 1, wherein the cation exchange resin is a calcium salt type.