GB2375105A - Water disinfection knitted matrix - Google Patents

Abstract

A water disinfection/filtration media comprising a knitted mesh of silver and copper wire. The wires may be silver-plated copper. Optionally the silver-plated copper wires and other wires with known bacteriacidal properties, e.g. zinc can be knitted together to provide a considerable surface area with an open matrix.

Description

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Water disinfection knitted matrix This application relates generally to water treatment media, specifically in the mechanics of disinfection.

Disinfection media are useful in the removal of unwanted bacteria and other species from water to render it safe for consumption.

For over two millennia it was known that two metals, copper and silver purified water, it was found that storage of water in copper vessels prevented the growth of algae, while silver kept the water potable. However it was only a hundred years ago that the oligodynamic action of such metals on biological processes became understood. It is now known that silver attaches to sulphur atoms which link the helices of DNA in individual cells (bacteria) thus preventing replication and growth, while copper has a pronounced effect on the photochemical reproduction of algae and certain bacteria. It is known that there is synergism between the two metals, as with other chemical species which further oxidise and complex the metals ions rendering them more soluble in water.

The common methods of treatment by adding dilute solution or releasing the metals electrochemically are fraught with problems, particularly in controlling the final concentrations in the treated water, as both copper and silver are toxic to humans and other vertebrates.

The present Invention, seeks to provide an improved disinfection method by overcoming many of these problems by providing a strictly controlled amount to Bacteria coming into contact with a knitted mesh of silver-plated copper wires, placed in a cartridge or container. The differences in electromotive series between the various metals and alloys, cause release of minute quantities of the metal ions allowing for their uptake by any micro-organisms.

One preferred embodiment of the media comprises of six separate strands of wire which are grouped together and then knitted together to provide a considerable surface area with an open matrix. Optionally, the silver coated copper wire and other wires with known bactericidal properties (such as zinc) can be knitted together in differing proportions.

Preferred embodiments provide a swift and efficient method of disinfecting large volumes of hot or cold water and can be used within widely available water filtration apparatus including plumbed in in-line devices.

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Tested disinfection media Work undertaken by South West Water Scientific Laboratory, Countess Wear, Exeter, Devon, (NAMAS accredited), on the action of a wound'bung'of knitted silver coated copper wire on a range of pathogenic bacteria, demonstrates the efficacy of this unique process over other disinfectants. Their results are appended.

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Micro-biological Assay of the Kill Rate of Bacteria by Knitmesh Silver Plated Copper Wire Undertaken by the South West Water Scientific Services Laboratory, Countess Wear, Exeter Bacterial Kill Experiments

Organism Condition To Tl T3 T6 Tl2 T24 T48 E. coli Silver plated 3.9 x 105/ml 3.8 x 105/ml 5.2 x 104/ml 1.1 x 103/ml < 1/ml < 1/ml < 1/ml Knitted mesh (ATCC 25922) Control 5. 4 x 105/ml 4.8 x 105/ml 2.4 x 105/ml 2. 6 x 105/ml 4.7 x 104/ml 2.9 x 104/ml 48/ml Pseudomonas Silver plated 2. 6 x 105/ml 2.1 x 104/ml 3.0 x 103ml 6. 3 x 102/ml 5/ml < l/ml < l/ml aeruginosa Knitted mesh (ATCC 27853 Control 1.6 x 105/ml 3.4 x 104/ml 2.8 x 103/ml 65/ml 7/ml 2/ml < 1/ml Staphaureus Silver plated 3. 5 x 102/ml 1. 6 x 102/ml 22/ml 2/ml < 1/ml < 1/ml < 1/ml Knitted mesh (ATCC 6538P) Control 5.7 x 104/ml 4.3 x 104/ml 3.4 x 104/ml 3.9 x 104/ml 2.2 x 102/ml 1/ml < 1/ml Entero. Silver plated 3. 3 xl05/ml 1. 3 x 105/ml 1.2 x 104/ml 6/ml < 1/ml < 1/ml < 1/ml Aerogenes Knitted mesh * (ATCC Control 2. 4 x 105/ml 1. 8xl0/ml 1. 8 x 105/ml 1. 9 x 105/ml 9 x 104/ml 3. 6 x 05/ml 3. 8 x 1Q6/ml 13048)

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Micro-biological Assay of the Kill Rate of Bacteria by Knitmesh Silver Plated Copper Wire Undertaken by the South West Water Scientific Services Laboratory, Countess Wear, Exeter

Organism Condition To Tl T3 T6 T12 T24 T48 Total Viable Silver plated 8. 3 x 104/ml 4. 1 x 10/ml 4. 8 x 104/ml 7. 7x 104/ml 2. 3 x 105/ml 6. 2 x 105/ml 9. 3 x 10/mol Count at Knitted mesh 220C Control 1. 1.8 x 105/ml 9.5 x 104/ml 9.1 x 104/ml 9. 6 x 104/ml 9.2 x 104/ml 5.2 x 105/ml 30/ml Salmonella silver plated > 1.8 x 108/ml > 1.8 x 108/ml 2.5 x 105/ml 2. 0 x 104/ml 4.3 x 102/ml < 1/ml < 1/ml Knitted mesh * typhimurium ATCC 14028 Control* 9.0 x 105/ml 7.0 x 106/ml 2.2 x 107/ml 1.6 x 107/ml 5.4 x 105/ml 5.4 x 105/ml Legionella Silver plated Knitted mesh pneumophila 1 Control * 2. 5x 105/ml 1. 1 x O/ml 2. 6 x 105/ml 2.7 x 105/ml 2.5 x 104/ml 1.5 x 104/ml (NCTC 12821) # Performed in jar test

Claims (5)

1. f CLAIMS 1. A filtration/disinfection media made from a combination of knitted wire.
2. 2 A filtration/disinfection media as in claim 1, in which the knitted wire is made from a combination of copper and silver.
3. 3. A filtration/disinfection media as in claim 2, which requires no external power source.
4. 4 A method of disinfecting fluids by providing the antibacterial effects of copper and silver without an external power source.
5. 5. A method of disinfecting water below boiling point.