Storage-stable aqueous solutions of chlorine dioxide and methods for preparing and using them
The present invention is for extremely pure solutions of chlorine dioxide, methods for making such solutions and to compositions and methods for storing, shipping and using such solutions. Generally, the chlorine dioxide solutions of the invention are aqueous solutions containing about 2500 ppm or less of total impurities. The chlorine dioxide solution can be prepare by passing dilute highly pure chlorine gas through a bed of substantially solid sodium chlorite and contacting the resulting chlorine dioxide gas with a liquid.
1. An apparatus for holding aqueous chlorine dioxide comprising: a storage container and a stable aqueous solution of chlorine dioxide containing about 1000 ppm or less of total impurities, wherein a starting concentration of chlorine dioxide in the solution is about 2000 ppm to 4500 ppm by weight, and wherein the solution retains at least 90% of the starting concentration of chlorine dioxide after 90 days at 40° C. when sealed within the storage container.
2. The apparatus of claim 1 , wherein the container comprises high density polyethylene.
3. The apparatus of claim 1 , wherein the container further comprises an inner surface treated with a chemical to reduce the rate of chlorine dioxide loss prior to addition of the chlorine dioxide solution, wherein the chemical used to treat the container is selected from the group of chemicals consisting of chlorine dioxide, chlorine and fluorine.
4. The apparatus of claim 1 , wherein the container comprises glass.
5. The apparatus of claim 1 , wherein the container comprises biaxially oriented polymers.
6. The apparatus of claim 1 , wherein the container comprises polyethylene.
7. The apparatus of claim 1 , wherein the container comprises polyethylene terephthalate.
8. The apparatus of claim 1 , wherein the container has a temperature of about 20° C. or less.
9. The apparatus of claim 1 , wherein the concentration of chlorine dioxide in the container is about 2500 ppm to 4500 ppm by weight and the container is flexible and has a gaseous headspace of about 1% of the container volume or less.
10. An apparatus for holding aqueous chlorine dioxide comprising:
a storage container; and
a stable aqueous solution of chlorine dioxide containing a starting concentration of about 2500 ppm by weight or more of chlorine dioxide in water and 1000 ppm or less of total impurities;
wherein said container is capable of storing said aqueous solution of chlorine dioxide for at least 90 days at a temperature up to 40° C. and retaining at least 90% of the starting concentration of chlorine dioxide when sealed within the storage container.
11. The apparatus of claim 10 , wherein the container comprises high density polyethylene.
12. The apparatus of claim 10 , wherein the container further comprises an inner surface treated with a chemical to reduce the rate of chlorine dioxide loss prior to addition of the chlorine dioxide solution, wherein the chemical used to treat the container is selected from the group of chemicals consisting of chlorine dioxide, chlorine and fluorine.
13. The apparatus of claim 10 , wherein the container comprises glass.
14. The apparatus of claim 10 , wherein the container comprises biaxially oriented polymers.
15. The apparatus of claim 10 , wherein the container comprises polyethylene.
16. The apparatus of claim 10 , wherein the container comprises polyethylene terephthalate.
17. The apparatus of claim 10 , wherein the concentration of chlorine dioxide in the container is about 3000 ppm by weight and the container is flexible and has a gaseous headspace of about 1% of the container volume or less.