GB2167053A - Products containing charcoal and their use in water purification - Google Patents

Abstract

Charcoal, either as free particles or borne on a substrate, is contained within a water-permeable material, e.g. within two sheets, bonded together at their edges, of such a material.

Description

SPECIFICATION Products containing charcoal and their use in water purification This invention relates to products suitable for use in water purification. Such a product, according to the invention, comprises charcoal contained within a water-permeable material.

The charcoal may be provided in particulate or granulate form or, preferably, as a charcoal-bearing substrate such as a paper or foam material within or on which charcoal particles are provided.

Alternatively, the charcoal-bearing substrate may be charcoal cloth. A bactericidal charcoal cloth or felt, e.g. of the type described in GB-A-2127389, may also be used.

The water-permeable material may be, for example, a fabric or plastics material. For example, a paper-based fabric or polypropylene may be provided in sheet form, so that the charcoal is contained between two such sheets, bonded together at their edges. For this purpose, it is convenient that the material should be heat-sealable.

A charcoal-bearing substrate may be held freely within, or bonded to, the water-permeable material. The primary criterion is that water should be able to pass through the material and come into contact with the charcoal, without there being any possibility that charcoal particles disperse freely cut into the water. Alternatively, therefore, a product of the invention may be formed as a laminate of, say, charcoal cloth between two layers of water-permeable material, or the water-permeable material may form an envelope within which the charcoal is contained. If desired, a charcoal-bearing substrate can be bonded to the water-permeable material, e.g. between sealed edges of separate sheets of the water-permeable material. The product can be rigid or flexible.

A product of the invention allows water to be purified simply. One or more products, depending on their size and the volume of water, can be introduced and, if desired, removed from water at any stage when it is desirable to purify the water. Purification occurs as the result of adsorption of bacteria, viruses and/or organic contaminants on the charcoal. The necessary effect can take place in less than 60 seconds, and the product can then be removed. It is also satisfactory for a product of the invention to be kept in a volume of water to be stored, e.g. for drinking purposes.

For domestic purposes, a product of the invention may have dimensions of, for example, 10 to 150 mm, e.g. 50 mm square, and be relatively thin.

Larger products may be suitable for other purposes. Again, for domestic purposes, and for ease of removal, the product can be provided with a string. After usage, the product can be immediately ready for disposal.

1. A product, suitable for use in water purification, which comprises charcoal contained within a water-permeable material.

2. A product according to claim 1, in which the charcoal is in the form of particles borne on a substrate.

3. A product according to claim 1, which comprises charcoal cloth.

4. A product according to claim 2 or claim 3, in which the substrate or cloth is fixed to the waterpermeable material.

5. A product according to any preceding claim, in which the charcoal is contained between two sheets, bonded together at their edges, of waterpermeable material.

6. A water purification process, which comprises contacting contaminated water with a product according to any preceding claim.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Products containing charcoal and their use in water purification This invention relates to products suitable for use in water purification. Such a product, according to the invention, comprises charcoal contained within a water-permeable material. The charcoal may be provided in particulate or granulate form or, preferably, as a charcoal-bearing substrate such as a paper or foam material within or on which charcoal particles are provided. Alternatively, the charcoal-bearing substrate may be charcoal cloth. A bactericidal charcoal cloth or felt, e.g. of the type described in GB-A-2127389, may also be used. The water-permeable material may be, for example, a fabric or plastics material. For example, a paper-based fabric or polypropylene may be provided in sheet form, so that the charcoal is contained between two such sheets, bonded together at their edges. For this purpose, it is convenient that the material should be heat-sealable. A charcoal-bearing substrate may be held freely within, or bonded to, the water-permeable material. The primary criterion is that water should be able to pass through the material and come into contact with the charcoal, without there being any possibility that charcoal particles disperse freely cut into the water. Alternatively, therefore, a product of the invention may be formed as a laminate of, say, charcoal cloth between two layers of water-permeable material, or the water-permeable material may form an envelope within which the charcoal is contained. If desired, a charcoal-bearing substrate can be bonded to the water-permeable material, e.g. between sealed edges of separate sheets of the water-permeable material. The product can be rigid or flexible. A product of the invention allows water to be purified simply. One or more products, depending on their size and the volume of water, can be introduced and, if desired, removed from water at any stage when it is desirable to purify the water. Purification occurs as the result of adsorption of bacteria, viruses and/or organic contaminants on the charcoal. The necessary effect can take place in less than 60 seconds, and the product can then be removed. It is also satisfactory for a product of the invention to be kept in a volume of water to be stored, e.g. for drinking purposes. For domestic purposes, a product of the invention may have dimensions of, for example, 10 to 150 mm, e.g. 50 mm square, and be relatively thin. Larger products may be suitable for other purposes. Again, for domestic purposes, and for ease of removal, the product can be provided with a string. After usage, the product can be immediately ready for disposal. CLAIMS

1. A product, suitable for use in water purification, which comprises charcoal contained within a water-permeable material.

2. A product according to claim 1, in which the charcoal is in the form of particles borne on a substrate.

3. A product according to claim 1, which comprises charcoal cloth.

4. A product according to claim 2 or claim 3, in which the substrate or cloth is fixed to the waterpermeable material.

5. A product according to any preceding claim, in which the charcoal is contained between two sheets, bonded together at their edges, of waterpermeable material.

6. A water purification process, which comprises contacting contaminated water with a product according to any preceding claim.