DE2404010A1 - PROCESS FOR IMPRAEGNATING FILTER MATERIALS, IN PARTICULAR FELT-SHAPED FILTER MATERIALS, WITH CATALYTIC AND / OR BACTERICIDE OR BACTERIOSTATIC METALS AND / OR METAL COMPOUNDS - Google Patents

Description

GHH Basel AG-, Basel (Switzerland)

Method for impregnating filter materials, in particular filζiformη filter materials, with catalytic and / or bactericidal or bacteriostatic metals and / or metal compounds

The invention relates to a method for impregnating filter materials, in particular Felt-shaped filter materials with catalytically and / or bactericidal or bacteriostatic metals and / or metal compounds.

For cleaning liquids, especially water of various origins, e.g. river, baoh, Sea water, treated and untreated drinking water

etc., are a large number of filtering and clarifying-409833/0736

methods known. For example, river water can pass through a quick sand filter are separated from coarse particles and then cleaned in a natural gravel filter (groundwater recharge) to such an extent that it is already is drinkable. Chemical pretreatments (precipitation) and subsequent filtration can also be used, as well as Disinfection Waters of almost any kind can be cleaned in such a way that they are suitable for consumption. The numerous Methods of bulk water filtration are available however, no suitable methods and devices for filtering small amounts of water, e.g. for a household, for a house or for a small village, opposite. This is due to the fact that when cleaning small amounts of water the outlay on equipment becomes so great that the costs become too high.

There are already water filters and water purification devices known for small amounts of water, but these are not capable of removing water from dangerous water Bacteria and / or harmful chemicals contaminated. " is and / or has an unpleasant smell and / or taste, without eliminating the normally in uncontaminated Water containing minerals essential to health and viability is safe and economical to produce pure drinking water for humans and pets. For example, harmful bacteria are found in

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in a medium such as untreated activated carbon, but multiply in it and can already Re-infect purified water if the demand for water occurs only intermittently.

Filter materials made from coarse fibers can be used to clean liquids, especially water and / or use fine fibers and / or materials with a high to very high specific surface area, preferably a coarse fleece made of coarse fibers, the pores of which are spanned by a network of fine fibers and into which Substances with a high to the highest specific surface are embedded, so that a felt-shaped filter material results.

Such a felt-shaped filter material is capable of a wide variety of cleaning processes at the same time perform and thus allows to get by with a minimal amount of equipment, which is essentially limited to a pure clamping device for the universal felt-shaped filter material.

The main advantageous properties of such a filter material are:

1) Retention of coarse and fine particles, e.g. bacteria, up to 0.4 μτα.

2) By combining coarse fibers and fine fibers

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the filter material acts simultaneously as a coarse pre-filter and as a fine post-filter, whereby the pre-filter effect relieves the fine filtering. If you just used a filter of the appropriate fineness, it would clog up far too quickly.

3) Adsorption of inorganic and organic odor and Flavors, e.g. free chlorine * chlorophenol etc.

The cleaning of liquids, especially water, is not just about separating particles and the adsorption of inorganic and organic odors and flavors, but rather also influencing the vital activity of microorganisms, even if they are separated from the filter with other particles due to their size, as well as e.g. the catalytic splitting of certain substances, e.g. harmful substances or smells and flavors.

So that the desired chemical and physicochemical processes when flowing through the liquid, in particular of the water, through the filter material, in particular the above-mentioned felt-shaped filter material, occur, the flow rate must not be too high, which can be achieved by suitable selection of the filter material and the pressure of the liquid can be achieved.

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On the other hand, it is also advantageous if on the surface of the coarse fibers and / or fine fibers and / or Substances with a high to the highest specific surface area, finely divided substances are present that the vital activity of microorganisms, i.e. have a bactericidal or at least bacteriostatic effect, and / or the Accelerate and / or catalytically accelerate the adsorption and splitting of harmful substances or smells and flavors influence. This fine distribution of such substances results in a maximum contact area with the flowing liquid.

The invention therefore relates to a method for impregnating filter materials, in particular Filzförrnigen filter materials, with catalytically and / or bactericidal or bacteriostatic acting Metals and / or metal compounds that are practically insoluble in the liquid to be cleaned; this method is characterized in that one is an aqueous slurry of coarse fibers and / or Fine fibers and / or fabrics with a high to very high specific surface area have at least an aqueous solution a salt of a metal from the 1st to 5th period of the Periodic Table of the Elements and the metal salt (s) directly or after an intermediate precipitation as less soluble compounds, e.g. chlorides,

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2A04010

-D-

. in the strongly alkaline range at least to the largest Part as practically insoluble metal hydroxides and / or Metal oxides and / or metals on the coarse fibers and / or fine fibers and / or substances with high to highest specific surface, which is preferably in the form of a coarse fleece made of coarse fibers, whose pores are spanned by a network of fine fibers and in which the substances with high to the highest specificity Surface are stored.

In the accompanying drawings, FIGS. 1 to 4 show different embodiments of the felt-shaped Filter material before impregnation on various scales and FIG. 5 shows the values of R for the Elements with ordinal numbers 1 to 83.

Fig. 1 shows a cross section through the

Filter material enlarged 48 times. The water flows from bottom up through the filter material.

Fig. 2 shows a cross section through the filter material 240 times enlarged. The water flows also from bottom to top through the filter material.

Fig. 3 shows a plan view of the filter material 2400 times enlarged. You can see clearly the network of fine asbestos fibers over the coarse cellulose fibers.

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Fig. 4 shows a cross section through the filter material 2400 times enlarged. The water flows from bottom to top through the filter material. Here, too, you can see the network of fine asbestos fibers over the coarse cellulose fibers.

Fig. 5 shows the R values for the elements with the ordinal numbers 1 to 83, which are a measure for are the oligodynamic ^ action of the elements concerned and according to the equation

R =

can be calculated. A is the wavelength in cm corresponding to the ionization energy of the element in question. In the table work "Numerical values and functions from physics, chemistry, astronomy, geophysics, technology" by Landolt-Börnstein. the ionization energies are given in wave numbers. From the wave number V , the corresponding wavelength can easily be calculated using the following equation:

X x V = 1 cm

A is the difference between the atomic radius and the ionic radius of the element in question in cm. R is thus a dimensionless number. If R has values between 11 and 14, that element shows a

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oligodynamic ^ effect. The same is true for alloys and compounds whose R ¥ erte additively of the R values of the alloying constituents or the atoms of the compounds can be calculated by the the content of the alloy or the compound to the individual elements in atomic percent of corresponding fractions of R Values of these elements are added.

Fibers with a diameter are used as GiOf fibers from 0.005 to 0.5 mm and a minimum length of 1 mm, generally with a maximum length of 50 mm, in consideration e.g. natural cellulose, fibers made from regenerated cellulose, fibers made from natural or synthetic polyamides, Acrylic fibers, polyester fibers, polyvinyl chloride fibers, polyurethane fibers, polyolefin fibers, etc., for example, are suitable cotton, flax, hemp, jute, ramie and coconut fibers, wool, goat, calf, cow and horsehair, nylon fibers, Polyethylene terephthalate fibers, polypropylene fibers, polystyrene fibers, such as those used for textile purposes as well as pulp fibers used for paper production, e.g. those made from softwood or hardwood, cereal straw, Grasses and macerated rags, which can be cut to the correct length if necessary.

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Pipes with a diameter are used as fine fibers from 0.00005 to 0.005 mm and a minimum length of 1 mm, generally with a maximum length of 50 mm, in question, e.g. fibers made of the materials specified for the coarse fibers, Glass fibers (glass silk, beta), whiskers (thread-like single crystals), asbestos, artificial mineral fibers such as slag fibers, Rock fibers (rock wool), quartz fibers and the like.

The substances with a high to the highest specific surface should have a specific surface of at least

have at least 10 m / g. Suitable substances are e.g. silica gel

(up to 800 m / g), fuller's earth, optionally prepared or surface-coated kieselguhr, activated carbon (up to 1000 m / g), activated aluminum oxide, zeolites, etc.

For example, a felt-shaped filter material may contain

20 to 80 kg, preferably 30 to 40 kg of coarse fibers 1 to 60 kg, preferably 30 to ² K) kg of fine fibers 10 to 50 kg, preferably 25 to 30 kg of substances

high to very high specific surface 0.01 to 6 % finely divided silver or silver compounds

0.01 to 5 % finely divided copper or copper compounds

0.01 to 5 % finely divided manganese or manganese compounds.

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The fibers can be crimped or drawn synthetic fibers, staple fibers, split fibers, etc. Asbestos fibers can be treated with acid and cleaned. The fibers (e.g. cellulose or asbestos fibers) can be fiberized by treatment in refiners or the like, until they have the desired fineness. The dimensions of the coarse and fine fibers and their proportions can be chosen so that the desired flow rate results. Suitable values can easily be determined through experiments.

For the production of the felt-shaped filter material ^ In principle, the methods of paper and cardboard manufacture can be applied. One can proceed in such a way that the coarse fibers are mixed with water and defibrated in a refiner, then the fine fibers, optionally in water slurried, added and again frayed in a refiner and finally the substances with a high to the highest specific surface, expediently suspended in water, mixes. This slurry can be used as starting material for the process according to the invention to serve.

Production takes place in order not to load the substances with a high or very high specific surface area with ions of the above suspension in water, for example with cation and anion exchangers of ions

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24ÖA010

was released. It is also advantageous to treat the coarse and / or fine fibers with weak or strong acids, for example to treat and then wash off well to remove the inside to remove the ions contained.

It is preferred to have the slurry prepared as described after settling by decantation to free most of the liquid. The thus obtained Pulp is e.g. on eftiem suction tape, as it is in paper and felt machinery is used, if appropriate converted into an endless belt with the supply of heat. the end This felt-shaped filter material can then be filter disks of the desired size, which can have a thickness of 2 to 10 mm, for example.

One · can replace certain metals by metals with the same R-value without creating an essential one Change in the catalytic effect results. According to these principles one can choose the metals and combine to achieve a catalytic cleavage of certain smells and flavors or others harmful substances should serve.

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To achieve a bactericidal or bacteriostatic effect, silver, gold, copper, chromium, nickel and arsenic or their compounds are preferred. The addition of the metals mentioned or their compounds can also promote the adsorption of harmful substances or odorous and cosmetic substances on the above-mentioned filter materials.

The metals or their compounds can be used individually or in a mixture with one another in amounts of 0.01 to 8 % _s based on the filter material. Metals from group Ib of the periodic table are preferably used in amounts of 1 to 8 % and metals from group VIIa of the periodic table preferably in amounts of 0.1 to 5 %, based on the filter material, either individually or in a mixture with one another.

The method according to the invention can, for example, be carried out in such a way that one in the form of a salt dissolved metal with a precipitant, e.g. sodium chloride, precipitates and the precipitated metal compound,

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eg a chloride, in a strongly alkaline medium by adding alkali, eg sodium hydroxide, with stirring
slowly converted into the metal and / or metal hydroxide and / or metal oxide, which is in finely divided
Shape on the coarse fibers and / or fine fibers and / or
Separates substances with a high to the highest specific surface.

But one can also pass away by converting a metal dissolved in the form of a salt directly as a hydroxide is deposited, which is optionally at least partially converted into the oxide by drying at a suitable temperature convicted.

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Claims (6)

Claims ί 1) \ Process for impregnating filter materials, in particular felt-shaped filter material ions, with catalytically and / or bactericidal or bacteriostatic metals and / or metal compounds which are practically insoluble in the liquid to be cleaned, characterized in that an aqueous suspension of coarse fibers and / or fine fibers and / or substances with a high to very high specific surface area a v / äs acid solution of at least one salt of a metal from the 1st to 5th period of the periodic table of the elements and the metal salt (s) directly or after a Zv / i see the fall as poorly soluble compounds, in the strongly alkaline range at least for the most part as practically insoluble metal hydroxides and / or metal oxides and / or metals on the coarse fibers and / or fine fibers and / or substances with a high to very high specific surface area. 2) Method according to claim 1, characterized in that the coarse fibers, fine fibers and fabrics with high to very high surface area to form a coarse fleece made of coarse fibers, the pores of which are covered by a network of fine fibers are overstretched and in which the substances with a high to the highest specific surface are embedded, processed. 409833/0736 3) The method according to claim 1 or 2, characterized in that to achieve a certain catalytic activity see salts of one or more metals are used, whose R value or their added R values according to the accompanying drawing are sufficient to bring about the desired cleavage. 4) Method according to one of claims 1 to 3 * characterized in that the metal salts in amounts from 0.01 to 8% with respect _t to the filter material used, namely salts of metals selected from the group Ib preferably in quantities of 1 to 8 % and salts of metals from group VIIa, preferably in amounts of 0.1 to 5 %, based on the filter material. 5) Process according to one of claims 1 to 4, characterized in that the metal dissolved in the form of a salt is precipitated with a precipitant, e.g. sodium chloride, and the precipitated metal compound, e.g. a chloride, is added by adding alkali, e.g. sodium hydroxide, strongly alkaline medium slowly converted into the metal and / or metal hydroxide and / or metal oxide with stirring, which is deposited in finely divided form on the coarse fibers and / or fine fibers and / or substances with a high to very high specific surface area. 6) Method according to one of claims 1 to 4, 409833/0736 characterized in that the metal dissolved in the form of a salt is deposited directly as hydroxide, which is optionally at least partially converted into the oxide by drying at a suitable temperature. 09833/0736