GB2420725A

GB2420725A - Pollution control

Info

Publication number: GB2420725A
Application number: GB0426619A
Authority: GB
Inventors: John Denby Downing; Keith Morris
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-04
Filing date: 2004-12-04
Publication date: 2006-06-07
Anticipated expiration: 2024-12-04
Also published as: GB0426619D0; GB2420725B

Abstract

A method of removing a pollutant from a liquid comprises a vulcanised rubber obtained from tyre reclamation plants. Preferably the rubber is a granulate or buffing and may be a natural or synthetic rubber or a mixture of both. The vulcanised rubber may be formed into mats or sprayed onto the polluted surface of water. Increased buoyancy may be provided by the addition of a water proof powder, priming or heat treating prior to use. Alternatively the vulcanised rubber is allowed, during use, to sink thus treating polluted waters where pollutant has sunk to the bottom of the water. Advantageously the method is employed to clean oil slicks thus protecting the shoreline.

Description

-1- 2420725 Pollution Control This invention concerns a method of

pollution control and particularly but not exclusively a method of removing a pollutant such as oil from water, and especially from seas, lakes or rivers.

Considerable damage has been caused over the years by oil pollution in seas lakes and rivers. Such pollution has often been caused by damage to an oil tanker or by such a ship cleaning its tanks at sea. When oil enters the water it tends to form an oil slick on the surface of the water which causes considerable damage to wildlife and the shoreline. Chemicals can be applied to disperse the slick but such chemicals can constitute pollutants in themselves. Methods of physically lifting the oil from the water have been used, but these are relatively difficult to carry out and have met with limited success due to the physical difficulties involved in handling the oil.

The term "rubber" when used in this specification is to be understood as referring to vulcanised natural or synthetic rubber, or mixtures of these.

According to the present invention there is provided a method of removing a pollutant from a liquid, the method comprising adding to the liquid a material in which the pollutant is absorbable, allowing time for the pollutant to be absorbed into the material, molecular absorbsion is created locking the pollutant into the absorbent.

The material when fully absorbed by the pollutant, prevents the pollutant from adhering to rocks or sand.

The liquid may be water which may be in the sea, a lake or a river. The material is particulate or can be formed into mats or other shaped material forms.

The material has a higher density than that of water but floats for a period of time dependent on water conditions. In a majority of cases this is sufficient to allow the material to effectively remove polluting material from the water. By introducing a 1-20 Micron finely divided water proof powder or by treating with heat or by priming the product, enhanced buoyancy is achieved.

The material may be added to the water by spraying from an air borne craft or a water borne craft or by land based personnel, either of which may also remove the material from the water.

The material is preferably supplied to substantially form a layer on the surface of the water.

Alternatively, the material may be retained within an open structure which permits entry of water. The open structure may comprise a net which may be towed behind a waterborne craft.

The material may be used untreated which would have a higher density than that of water and allowed to sink to the bottom of the water. This method would allow the material to treat pollutant which has sunk to the bottom of the water, locking it to the molecular structures of the material, thereby preventing further pollution.

Preferably the pollutant is subsequently removed from the material by washing with solvent or by compression to permit reuse of the material and/or pollutant. Or the material and pollutant may be used as fuel or in a pyrolysis system to recover oil and other useful by products.

The material may comprise rubber granulate or buffings which can be obtained from the tyre re-treading industry or rubber reclaiming plants.

Also according to the present invention there is provided a method of removing oil from water and protecting the shoreline according to any of the preceding paragraphs.

The invention will now be described in more detail with an indication of how the method may be carried out by way of example only.

The invention provides a method of cleaning up pollution and particularly oil slicks. Treated particulate rubber is dropped onto the slick to substantially form a layer thereon. The rubber may be in the form of rubber buffings which are obtained when buffing a tyre prior to retreading. Alternatively, or in addition, the rubber may be in the form of rubber granulates which are obtained during processing in a tyre reclaiming plant. The material is then treated by introducing a waterproof powder or by heat treating or priming to give buoyancy. The material may be applied to a slick by blowing on to the surface for example by using a cyclone fan. The rubber may be applied from a ship or alternatively from an aeroplane, or simply by hand from the shoreline.

Whilst the treated rubber is on the oil slick it absorbs the oil and floats on or very near the surface of the water in a manner similar to seaweed. The oil soaked rubber can then be taken out of the sea by suction or by nets. If required the rubber can be subsequently washed with solvent or compressed to remove the oil for subsequent reuse of the rubber and/or oil.

The treated rubber granules when sprayed onto the oil coated water soak up to three times their own weight of oil, locking the oil into the molecular structure of the treated rubber particles which in themselves are none poisonous and none toxic and environmentally friendly.

A typical composition of rubber buffings or crumbs is as follows:- Natural and synthetic rubber 35% Carbon Black 30% Zinc Oxide 5% Stearic Acid 3% Processing Oils 10% Fillers 10% Organic Accelerators 2% Other Components 5% This composition is stable at temperatures between minus 50 c and 150 c due to the vulcanising process used.

In an alternative method the rubber particles may be retained in a net or similar enclosure and towed behind a ship or boat through the oil slick. The saturated particles can be subsequently removed from the net for reprocessing or disposal.

There is thus described a method for pollution control which is suitable for use with oil slicks. This method is relatively easy to operate and does not produce harmful by products such as can be produced when dispersal agents are added to oil. The rubber particles used are readily and inexpensively available from for example the tyre industry.

Various other modifications may be made without departing from the scope of the invention. For example the rubber may be in a different form than those suggested. Materials which have the required properties other than rubber could be used, and particularly for cleaning materials other than oil.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination or features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Methods for removing oil pollutant from an expanse of water according to the invention will now be described with reference to the accompanying drawings in which:- Figure 1 - is a diagrammatic cross section of the material (A) and its molecular structure (B) Figure 2 - is a diagrammatic cross section of the material (C) the pollutant (D) the water (E) Figure 3 - is a diagrammatic cross section of the untreated material submerged on the bottom of the water. Water (F) the material (G) the pollutant (H) the bottom (I)

Claims

Claims.

1. A method of removing a pollutant from water especially from seas, lakes or rivers, but not exclusively from water. Composed of a vulcanised rubber granulate or buffing which can be obtained from tyre reclamation plants or the tyre re-treading industry.

2. The product used is a natural or synthetic rubber or a mixture of these.

3. The rubber can be treated to aid buoyancy if required by adding a 1-20 Micron finely divided water proof powder or by heat treatment or priming.

4. The rubber can be left untreated to allow the product to sink, thereby allowing the clean up of sea or river and lake beds or land based pollution.