JPS59193134A - Water purifying material - Google Patents

Abstract

PURPOSE:To obtain a water purifying material which is made possible to inhibit elution of Ag adsorbed by activated carbon by allowing a specified substance sparlingly soluble in water to coexist with the active carbon adsorbing Ag. CONSTITUTION:The water purifying material contains activated carbon adsorbing Ag and/or inorg. Ag compd., and >= one kind of org. component among oxides, hydroxides, or oxyacid salts of Ca, Mg, and/or Al, as primary components. Preferred amt. of Ag adsorbed to the active carbon is 5-0.01wt% expressed in terms of Ag. The proportion of the inorg. components in the water purifying material is usually 0.1-100pts.wt. basing on 100pts.wt. activated carbon component. When the water purifying material is used for the purification of, for example, city water, purification of about 5m<3> of water is possible with 100g of the water purifying material. The content of Ag in the purified water is only several ppb which is far lower than the upper limit value, i.e. 50ppb regulated by Bureau of Public Health USA for the content of Ag in drinking water.

Description

[Detailed description of the invention] The present invention relates to water purification materials.

In recent years, water purifiers using activated carbon have been commercially available and widely used to remove chlorine, odorous substances, and harmful organic substances from tap water. Because the chlorine in the water has been removed, bacteria can breed inside the vessel, which is a problem from a sanitary standpoint. It is also known that the growth of bacteria in a water purifier can be suppressed by impregnating activated carbon in the water purifier with silver or a silver compound. However, in this case, the drinking water obtained by passing through the water purifier contains a considerable amount of silver, which is not desirable from a health standpoint.

In view of these points, the present inventors conducted various studies and found that the elution of silver can be suppressed by allowing a specific poorly water-soluble substance to coexist in the silver-impregnated activated carbon.

That is, the present invention provides: (1) activated carbon impregnated with silver and/or an inorganic silver compound (hereinafter also referred to as "activated carbon component");
It is a water purification material containing as a main component one or more of poorly water-soluble calcium, magnesium and/or aluminum oxides, hydroxides and oxyacid salts (hereinafter also referred to as inorganic components).

The active process components described above can be obtained by impregnating activated carbon with silver and/or inorganic silver compounds.

The activated carbon used here is coal and coke.

It is manufactured by a known method using charcoal, coconut shell, resin, animal bones, etc. as raw materials, and its specific surface area is 100%.
Any material with a density of ~2000 m2/g may be used. Its shape is, for example, spherical.

It may be cylindrical, crushed, powdered, granular, fibrous, etc., but powdered or crushed is preferred.

Examples of silver include metallic silver, colloidal silver, and silver ions. ■■■■■Inorganic silver compounds include silver halides such as silver chloride, silver bromide, and silver iodide, silver nitrate, silver sulfate, silver phosphate, silver sulfide, silver chlorate, silver silicate, and silver oxide. Examples include silver, among which silver chloride, silver nitrate, etc. are preferred.

In order to impregnate activated carbon with silver and/or an inorganic silver compound (hereinafter also simply referred to as silver component), the silver component is suspended in water or an organic solvent to the extent that it is soluble, impregnated into activated carbon, and then dried. Then, if necessary, it may be further fired, or the liquid of the silver component may be sprayed to an active level, and then dried and/or fired if necessary. In this case, for example, silver nitrate and common salt are made into separate aqueous solutions, and activated carbon is first impregnated with one of them, and then the other is impregnated to form silver chloride on the inner surface of the pores of the activated carbon. It is also possible to separately impregnate activated carbon with a water-soluble compound on the surface of the activated carbon.

The amount of silver component impregnated to the activated carbon is 5 to 0.01% by weight, preferably 1.0 to 0.05% by weight, based on the activated carbon. If the amount of silver component is too small, it will not be possible to sufficiently suppress the growth of bacteria in the water purifier, and conversely, if the amount of silver component is too large, the amount of silver eluted will increase, causing this problem. In order to suppress this, a large amount of inorganic components are required, which is not preferable.

The inorganic component is one or more of oxides, hydroxides and oxyacids of calcium, magnesium and/or aluminum, and has a solubility in distilled water of 25 tE in terms of calcium, magnesium and/or aluminum. /100Ashi7 or less, preferably 10-3g/l 00π7~108g/l 00trt
It belongs to l. Specific examples include oxides such as magnesium oxide, porous alumina oxide, and porous spinel; for example, magnesium hydroxide (
hydroxides such as aluminum hydroxide, double hydroxides of magnesium aluminum (such as manasite, hydrotalcite, etc.), double hydroxides of calcium aluminum (such as alunite), carbonic acid, etc. μcium (e.g. calcite, etc.), magnesium carbonate (e.g. magnesite, etc.), magnesium calcium carbonate (e.g. dolomite, etc.), apminium phosphate, calcium phosphate (e.g. evaapatite, etc.), aluminum silicate, magnesium silicate, Examples include oxyacid salts such as calcium silicate (e.g., evatobermorite, sheet dryride, etc.).

These inorganic components may be composed of only one kind, or may be a mixture of two or more kinds, and may further contain keys and other compounds that are mainly composed of these inorganic components. Inorganic substances containing these inorganic components as main components include zeolite, permicuphyte, montmorillonite, kaolinite, mica clay minerals, halloysite, metahalloysite, sepiolite, palligoskite, chlorite, bone charcoal, shells, and coral. Among these, sepiolite, vermiculite, zeolite, and bone charcoal are preferred, and bone charcoal is preferred.

Sepiolite is particularly preferred.

The water purification material of the present invention contains the activated carbon component and the inorganic component as main components, but when bone char obtained from animal bones is used as the activated carbon in the activated carbon component, the activated carbon component contains bone char. It can also serve as the inorganic component. The water purification material of the present invention is usually used in a state where the activated carbon component and the inorganic component are uniformly mixed, but it may also be a material in which a layer of the activated carbon component and a layer of the inorganic component are stacked. These layers may be stacked one after the other to form multiple layers of 4 to 10 layers. The activated carbon component and/or the inorganic component may be used alone or in combination by spinning or forming into fibers or sheets. The proportion of the inorganic component in the water purification material of the present invention is usually 01 to 100 parts by weight per 100 parts by weight of the activated carbon component.
Preferably, the weight is 1 to 45%.

To purify water using the water purification material of the present invention, it is usually done by placing the water purification material in a water purifier and passing water through it. It can be done. When using a water purification material made of multiple layers of activated carbon components and non-alternative components, it is preferable to pass water through the activated carbon component layer and then the inorganic component layer. The water purifier has a good water purification effect, and bacteria will not grow inside the device for a long time after you start using it.

For example, when the water purification material of the present invention is used to purify tap water, it is possible to purify approximately 5 m3 with 10 (l) of the water purification material, and it can usually be used for about half a year in a general household kitchen. Also, the concentration of silver in purified water is
) pb, which is far below the US Public Health Service's upper limit of 50 ppb for silver concentration in drinking water, for example.

The water purification agent of the present invention is useful not only for purifying drinking water, but also for removing bacteria from water used when bacteria are grown in biotechnology, and for removing bacteria from water used in production plants such as LSI. Also, it can still be used to prevent stored water from spoiling.

EXAMPLES The present invention will be described in more detail with reference to Examples below.

Example / Dissolve 0.157 g of silver nitrate (0.1 g in terms of silver) in 50 ml of water, and sprinkle this evenly over 10 liters of activated carbon.
It was washed with water and dried to obtain silver-impregnated activated carbon (activated carbon component). A water purifying agent was obtained by mixing 5 g of this silver-impregnated activated carbon with 0.5 g of the inorganic components listed in Table 1. The results are shown in Table 1.

[Test 1] Measurement of silver elution amount A 20'Ort;l Erlenmeyer flask and water purification material were placed in a 2. O
To this was added 100 ml of distilled water, left overnight at 25°C, sifted, and the silver concentration was measured using an atomic absorption spectrophotometer.

[Test 2] Antibacterial effect in retained water Add 100πl of tap water to a sterile wide-mouth reagent bottle (240g? capacity)
and 5-5ff of water purification material were added. Add to this a test bacteria solution (Pseudomonas aeruginosa).
Engineering FO3080 and Eachrichia col
i Engineering FO30445, OXl Q7ceil/ Ml
Inject 0.5 ml of [containing]
The mixture was allowed to stand for 4 hours, and the number of viable bacteria in the supernatant was measured using a pour plate culture method C standard agar medium 35t (48 hours). Results first
Shown in the table.

Note 0 Shirasagi M (Takeda Pharmaceutical steam activated powdered charcoal BET specific surface area 1133m17/raw material sawdust) OWH2C (
Takeda Pharmaceutical Steam Activated Crushed Charcoal B'ET Specific Surface 1121
m2//98~32mesh raw material coconut shell) Example λ Pour tap water from step 11 into a transparent bottle of long-term storage water 171, pack it with 5.5 g of water purification material in a non-woven fabric, and store it as a window at room temperature for one month. I left it in the place marked H.

The preserved water was poured into a transparent coffin and the results were observed.
: Shown in Table 2.

Table 2

Claims (1)

[Claims] ■ Activated carbon impregnated with silver and/or inorganic silver compounds; ■ Slightly water-soluble calcium, magnesium and/or
Or a water purification material containing one or more of aluminum oxides, hydroxides, and oxyaltates as a main component.