GB2312424A

GB2312424A - Treatment of spillages of chlorine or hypochlorite

Info

Publication number: GB2312424A
Application number: GB9608389A
Authority: GB
Inventors: Stephen Stanley Smith
Original assignee: Wallace and Tiernan Ltd
Current assignee: Wallace and Tiernan Ltd
Priority date: 1996-04-23
Filing date: 1996-04-23
Publication date: 1997-10-29
Anticipated expiration: 2016-04-23
Also published as: GB9608389D0; GB2312424B

Abstract

Spillages of liquid chlorine or a alkali metal hypochlorite solution are neutralised by treating the spillage with an inorganic chemical reagent capable of reacting with the spilled material to produce a non-hazardous solid product. The chemical reagent may be pressurised in a storage device for discharge in the event of a spillage. Alternatively, the solid reagent may be contained within a porous covering.

Description

TREATMENT OF SPILLAGES The present invention relates to the treatment of a spillage, leak or other unwanted discharge (hereinafter referred to generically as a spillage) of liquid chlorine or alkali metal hypochiorites to prevent generation of potentially harmful fumes.

For convenience such treatment is referred to herein as neutralisation.

Liquid chlorine and solutions of alkali metal hypochlorites (particularly sodium hypochlorite) are chemicals used extensively in the treatment of water to destroy or control bacteria which may be present therein. Thus, these chemicals are used for the treatment of water from reservoirs before it is supplied to the public mains and also for the treatment of water in swimming pools.

Liquid chlorine is usually stored in a drum or cylinder whereas alkali metal hypochlorites may be stored either in drums (usually of a concentration of about 15%) or in tanks (usually of a concentration of 1% to 15%). Great care is of course in the storage and handling of these chemicals but nevertheless spillages do occur resulting in the generation of harmful fumes and action must be taken to deal with the spillage.

In the case of spillages of liquid chlorine, the currently recommended procedure is to build an earth or sand band to contain the spillage which is then simply allowed to "evaporate" so that the fumes are diluted, and carried away, by the atmosphere. Although the liquid spillage is contained effectively by the band, the fumes still present a danger to personnel within "gas reach".

Spillages of hypochlorite solution are dealt with primarily by washing away the spillage (which generates harmful fumes) with copious quantities of water which is often then simply flushed down a public drain.

Clearly the above methods of dealing with spillages are unsatisfactory since there is no containment of the fumes and, in the case of hypochlorite, the spillage enters the drainage system.

It is therefore an object of the present invention to obviate or mitigate the abovementioned disadvantages.

In its first, broadest aspect the present invention provides a method of neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the method comprising treating said spillage with an inorganic chemical reagent capable of reacting with at least one of chlorine or an alkali metal hypochlorite to produce a non-hazardous solid product.

Therefore in accordance with the invention the chemical reaction reacts with the liquid chlorine or alkali metal hypochlorite solution to produce a solid non-hazardous inorganic salt thus preventing release of further fumes.

The inorganic chemical reagent may be applied as a solution (e.g. by pressurised discharge of the solution) or as a solid.

The inorganic chemical reagent preferably comprises a sulphite, thiosulphite or hydrogen sulphite (i.e. a bisulphite), all of which are capable of neutralising liquid chlorine and alkali metal hypochlorite solutions to produce the non-hazardous products sodium chloride and sodium sulphate. More preferably it is the alkali metal (most preferably sodium) form of these compounds which is used.

According to a second aspect of the present invention there is provided a device for neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the device incorporating an inorganic chemical reagent capable of reacting with at least one of liquid chlorine or an alkali metal hypochlorite to produce a non-hazardous, solid inorganic product, said inorganic chemical reagent being pressurised in the device for discharge in the event of said spillage.

According to a third aspect of the invention there is provided a storage installation at which liquid chlorine or alkali metal hypochlorite solution is stored, the installation being provided with a device in accordance with the second aspect of the invention for discharge in the event of said spillage.

The device of the second aspect of the invention allows the inorganic chemical reagent to be discharged (under pressure) to neutralise the spillage.

Obviously discharge should continue until all of the spillage has been converted into a solid product which may then be disposed of easily and safely.

Preferably the chemical reagent used in the device of the second aspect of the invention is capable of neutralising both liquid chlorine and solutions of alkali metal hypochlorites.

For preference the inorganic chemical reagent is used as a solution (particularly an aqueous solution) of concentration 150 to 250 grams per litre. The inorganic chemical reagent preferably comprises a sulphite, thiosulphite or hydrogen sulphite (i.e. a bisulphite) as described above.

The device of the first aspect of the invention may be a conventional air pressured extinguisher with a fine spray nozzle attached. The device may be portable or may be a fixed installation.

If desired the reagent solution may incorporate an anti-freeze to allow the device to be used in cold weather conditions.

According to a fourth aspect of the invention there is provided a device for neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the device comprising a solid inorganic chemical reagent capable of reacting with at least one of chlorine or alkali metal hypochlorite to produce a non-hazardous solid product, said solid reagent being contained within a porous covering.

The device of the fourth aspect of the invention is intended for use as a "chemical bund" to be provided around a spillage so as both to contain the spillage and provide for neutralisation thereof as the spilt chemicals come into contact with the inorganic reagent.

Preferably the chemical reagent used in the device of the fourth aspect of the invention is capable of neutralising both liquid chlorine and solutions of alkali metal hypochlorites.

The inorganic reagent is preferably a sulphite, thiosulphite or hydrogen suiphite, as described above.

The device of the fourth aspect of the invention preferably also incorporates an inert absorbent material, e.g. vermiculite.

Preferably the contents of the device of the fourth aspect of the invention are in particulate or granular form.

The porous covering of the device may, for example, be of a fabric material, e.g. muslin or nylon.

It will be appreciated that once the device has been used for neutralising a spillage, it (i.e. the device) is harmless because it contains only harmless solid chemicals.

Claims

1. A method of neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the method comprising treating said spillage with an inorganic chemical reagent capable of reacting with at least one of chlorine or an alkali metal hypochlorite to produce a non-hazardous solid product

2. A method as claimed in claim 1 wherein the chemical reagent is applied to the spillage as a solution.

3. A method as claimed in claim 2 wherein the application is by pressurised discharge.

4. A method as claimed in claim 1 wherein the chemical reagent is used as a solid.

5. A method as claimed in any one of claims 1 to 4 wherein the chemical reagent comprises a sulphite, thiosulphite or hydrogen sulphite.

6. A method as claimed in claim 5 wherein the chemical reagent is a alkali metal sulphite, alkali metal thiosulphite or alkali metal hydrogen sulphite.

7. A method as claimed in claim 6 wherein the chemical reagent comprises sodium sulphite, sodium thiosulphite or sodium hydrogen sulphite.

8. A device for neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the device incorporating an inorganic chemical reagent capable of reacting with at least one of liquid chlorine or an alkali metal hypochlorite to produce a non-hazardous, solid inorganic product, said inorganic chemical reagent being pressurised in the device for discharge in the event of said spillage.

9. A device as claimed in claim 5 wherein the chemical reagent comprises a solution of a sulphite, thiosulphite or hydrogen sulphite.

10. A device as claimed in claim 9 wherein the chemical reagent comprises a solution of an alkali metal sulphite, alkali metal thiosulphite or alkali metal hydrogen sulphite.

11. A device as claimed in claim 7 wherein the chemical reagent comprises a solution of sodium sulphite, sodium thiosulphite or sodium hydrogen sulphite.

12. A device as claimed in any one of claims 9 to 11 wherein the solution is an aqueous solution.

13. A device as claimed in any one of claims 9 to 12 wherein the solution has a concentration of 150 to 250 grams per litre.

14. A device as claimed in any one of claims 8 to 13 wherein the chemical reagent incorporates an anti-freeze.

15. A storage installation at which liquid chlorine or alkali metal hypochlorite solution is stored, the installation being provided with a device as claimed in any one of claims 8 to 14 for discharge in the event of said spillage.

16. A device for neutralising a spillage of liquid chlorine or an alkali metal hypochlorite solution, the device comprising a solid inorganic chemical reagent capable of reacting with at least one of chlorine or alkali metal hypochlorite to produce a non-hazardous solid product, said solid reagent being contained within a porous covering.

17. A device as claimed in claim 16 wherein the chemical reagent comprises a sulphite, thiosulphite or hydrogen sulphite.

18. A device as claimed in claim 17 wherein the chemical reagent comprises an alkali metal sulphite, alkali metal thiosulphite or alkali metal hydrogen sulphite.

19. A device as claimed in claim 18 wherein the chemical reagent comprises sodium sulphite, sodium thiosulphite or sodium hydrogen sulphite.

20. A device as claimed in any one of claims 16 to 19 further incorporating an inert absorbent material.

21. A device as claimed in claim 16 wherein the inert absorbent material is vermiculite.

22. A device as claimed in any one of claims 16 to 21 wherein the contents of the device are in particulate or granular form.

23. A device as claimed in any one of claims 16 to 22 wherein the covering device is of a fabric material.

24. The use of an alkali metal sulphite, alkali metal thiosulphite or alkali metal hydrogen sulphite for the neutralisation of spillages or liquid chlorine or alkali metal hypochlorite solutions.