Treatment of chemical agent hydrolysates
The present invention relates generally to the destruction of chemical weapons. In particular, the present invention relates to methods for treating hydrolysates of chemical agents. In one embodiment, the present invention provides a method for heating solids resulting from precipitation of organophosphorus compounds to make them un-recombinable. In another embodiment, the invention relates to solidification of hydrolysate into a solid with or without the presence of an oxidizer.
1. A method of precipitating one or more organophosphorus compounds from a first solution, comprising: contacting the first solution with an iron salt to form a second solution and solidifying from the second solution a solid comprising at least one organophosphorus compound comprising an iron-phosphorus polymer, wherein the molar ratio of iron to organophosphorus compound in the second solution is from about 1:3 to about 10:1.
2. The method of claim 1 , wherein the molar ratio of iron to organophosphorus compound is around 3:1.
3. The method of claim 1 , wherein the molar ratio of iron to organophosphorus compound in the second solution ranges from about 4:1 to about 5:1.
4. The method of claim 1 , wherein the molar ratio of water to organophosphorus compound in the second solution is below about 100:1.
5. The method of claim 4 , wherein the molar ratio of water to methyl phosphoric acid (MPA) in the second solution is below about 80:1.
6. The method of claim 5 , wherein the molar ratio of water to MPA in the second solution is below about 50:1.
7. The method of claim 1 , wherein the pH of the second solution ranges from about 4.5 to about 6.0.
8. The method of claim 7 , wherein the pH of the second solution is about 5.0.
9. The method of claim 1 , wherein the solid further comprises one or more organosulfur compounds.
10. The method of claim 1 , wherein the first solution comprises oxidized or un-oxidized hydrolysate of a chemical agent.
11. The method of claim 10 , wherein the chemical agent is selected from the group consisting of VX, RVX, Sarin, Soman, and Tabun.
12. The method of claim 1 , further comprising separating the precipitated iron-phosphorus polymer from the aqueous solution.
13. The method of claim 12 , further comprising heating the separated iron-phosphorus polymer.
14. The method of claim 13 , wherein said heating comprises heating to a temperature of about 300° C. to about 500° C. for a period of time ranging from about 30 min to about 120 min.