Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
  • C02F1/505—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment by oligodynamic treatment

Definitions

• the invention is therefore based on the object of enabling the storage of water and aqueous solutions, but in particular of drinking water, for several years.
• the new molded bodies which ensure that germs are not kept free from water-soluble but water-soluble metals achieve binding with a solubility of at most 100 mg / liter, which is brought into a form in which it does not disintegrate in the aqueous environment.
• the present invention allows a long-term effect, since the effective concentration of metal ions according to the solubility product of the salt is reached very quickly and then remains constant until the metal compound has completely dissolved .
• the present invention relates to a process for the production of molded articles for the release of active substances which do not disintegrate in the aqueous environment, which is characterized in that at least one metal compound which is sparingly soluble in water and prevents the development of germs or deformed without carrier substances under a pressure of at least 8000 kg / cm 2 and activates the body or melts this metal compound onto an inert carrier.
• the following description mainly refers to the use of silver compounds. Although such compounds are preferred for certain fields of application, other poorly soluble metal compounds, such as copper, tin, mercury compounds, can also be used.
• a sparingly soluble metal compound for example a sparingly soluble silver compound, such as silver chloride AgCl, silver bromide AgBr, silver phosphate Ag 3 PO 4 , silver oxide / silver hydroxide, silver carbonate Ag 2 CO 3 , etc., thus allows an effective silver ion concentration to be kept constant, which is necessary to keep pure bacteria free of germs Water or certain aqueous solutions is necessary and sufficient.
• the silver ion concentration is about a power of ten higher than that of pure silver halide.
• the "activation" can be carried out by adding a more soluble silver salt, for example silver phosphate, silver carbonate or silver hydroxide in the order of magnitude of about 1 to 10% to the silver chloride or bromide.
• the activation can also be carried out by thermal or chemical treatment, in particular in tablet form, for example by briefly heating the surface to high temperatures, preferably not more than 10 seconds in general, preferably to about 1000 ° C., for example with hot gases, by acid treatment, etc. on the surface of the molded body at least in part a silver oxide / silver hydroxide layer, which has a larger solubility product.
• thermal or chemical treatment in particular in tablet form, for example by briefly heating the surface to high temperatures, preferably not more than 10 seconds in general, preferably to about 1000 ° C., for example with hot gases, by acid treatment, etc. on the surface of the molded body at least in part a silver oxide / silver hydroxide layer, which has a larger solubility product.
• silver hydroxide and silver oxide are to be regarded as identical, since silver hydroxide is known to be subject to an aging process which leads to the oxide with the elimination of water from hydroxide.
• a sufficiently high, initial silver ion concentration is necessary in order to effectively treat germ-containing water or aqueous solutions, i.e. to sterilize.
• Table I lists the solubility products and the silver content of an equilibrated aqueous solution in milligrams / liter for some poorly soluble silver compounds:
• the poorly soluble silver or other suitable metal compound is most conveniently used in the form of an optionally activated tablet.
• the essence of such a tablet is that metal ions dissolve to the same extent as they form a firm bond with microorganisms in aqueous solution, according to the solubility product of the tablet. When containers are closed, this ensures that water or aqueous solutions have a practically unlimited shelf life (i.e. germ-free), even with repeated recontamination.
• the shaped bodies for example tablets, can be produced, for example, by pressing the desired amount of one or more poorly soluble silver compounds at a pressure of at least 8000 kg / cm 2 up to 15 t / cm 2 into bodies of the desired shape and size, for example tablets , Cubes, pearls, chopsticks and the like.
• activation is generally necessary.
• the tablets are advantageously placed in an ion-permeable plastic membrane, e.g. "Metricel VF-6" from Gelman, pore size 0.45 u, welded in, as they can disintegrate in the water under heavy mechanical stress (e.g. ultrasound) or when hot.
• an ion-permeable plastic membrane e.g. "Metricel VF-6" from Gelman, pore size 0.45 u, welded in, as they can disintegrate in the water under heavy mechanical stress (e.g. ultrasound) or when hot.
• Silver chloride and silver bromide or other suitable metal compounds can also be carried on an inert support, e.g. Silver, gold or platinum wire, magnesium oxide, aluminum oxide, are melted and used in this form.
• the moldings according to the invention are particularly suitable
• the minimum concentration of silver ions required in water, which is usually necessary and sufficient to keep it germ-free, is 0.1 to 1.0 mg / liter.
• initial silver ion concentrations of up to about 5 mg / liter are indicated.
• the silver compounds are used in such an amount that the active substance concentration is at most 10 mg / liter.
• the dosage is 200 mg of sparingly soluble silver compound for 10 to 60 liters Water, depending on the desired duration of sterile maintenance.
• Fig. 1 is a magnesium oxide rod, which is coated at one end with molten silver chloride, and
• Burnt magnesium oxide as it is pressed into thin rods in qualitative inorganic-analytical chemistry for the borax pearl, is heated in the Bunsen burner flame to a bright red glow and the heated end is immersed in finely powdered silver chloride.
• the substance stuck to the stick is carefully melted in the Bunsen burner flame so that a compact silver chloride coating is formed over a length of approx. 30 mm.
• Much silver chloride is melted onto the stick until the entire desired amount (usually approx. 200 mg) adheres to the magnesium stick.
• the sticks are broken in two without touching them with your fingers (hand fat) at the substance boundary and placed in the appropriate container (Fig. 1). Additional activation is not necessary, since enough silver oxide has been generated by the melting process.
• the amount of liquid was mixed well by swirling and the top was removed using sterile pipettes.
• the corresponding dilutions (1 ⁇ 10 - 1 to 1 ⁇ 10 - 5 ) were membrane filtered (Gelman membrane filter Metricel GN 6 Metricel, at a filtering rate of 2 liters per minute). Samples were taken later daily after the hourly values had been evaluated.
• the membrane filters were each placed on a CLED (Cysteine Lactose Electrolyte Specific Agar BBL) plate and incubated for 48 hours at 37 ° C. Since there was no significant difference in the oligodynamic silver effect in the temperature range from 20 to 37 ° C, the further tests were carried out at room temperature. The results can be seen from the accompanying drawing (Fig. 2).
• the duration of the investigation was between 5 and 11 days. During this time, neither the humidification system nor any existing breathing hoses were replaced, both of which had previously been changed daily, only the water loss in the water chamber was cleaned with sterile aqua dest. added.

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• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

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Citations (5)

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• 1982
  • 1982-04-01 WO PCT/CH1982/000051 patent/WO1982003381A1/de not_active Ceased
  • 1982-04-01 JP JP57501029A patent/JPS58500472A/ja active Granted
  • 1982-04-01 AU AU82098/82A patent/AU554311B2/en not_active Ceased
  • 1982-04-01 BR BR8207251A patent/BR8207251A/pt unknown
  • 1982-04-01 EP EP82900931A patent/EP0075566B1/de not_active Expired
  • 1982-04-01 DE DE8282900931T patent/DE3266122D1/de not_active Expired
  • 1982-04-01 DE DE82CH8200051T patent/DE3239707D2/de not_active Expired
• 1986
  • 1986-03-25 US US06/843,789 patent/US4749537A/en not_active Expired - Fee Related

Patent Citations (5)

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