Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil

1. A process of treating in-situ elemental mercury contamination within a soil comprising steps of:

providing an in-situ soil substrate having elemental mercury contamination;

introducing a supply of sulfur into a below ground region in proximity to the in-situ soil substrate;

heating the supply of sulfur in the below ground region to form a sulfur vapor;

directing the sulfur vapor from the below ground region and into the in-situ soil substrate having elemental mercury contamination;

precipitating, the sulfur within the in-situ soil substrate;

allowing the precipitated sulfur to react with residual elemental mercury present within the soil, thereby forming a reaction product of a mercury sulfide.

2. The process according to claim 1 wherein said step of introducing into a soil a sulfur vapor further comprises passing heated air through a mixture of course sand and elemental sulfur.

3. The process according to claim 1 wherein said step of introducing into a soil a sulfur vapor further comprises introducing a sulfur vapor through an access well.

4. The process according to claim 1 wherein said heating step further comprises heating the elemental sulfur to a temperature of between about 100° C. to about 207° C.

5. The process according to claim 1 wherein the step of heating a supply of elemental sulfur further comprises heating a supply of elemental sulfur present within an access well.

6. The process according to claim 1 wherein said step of heating further comprises heating the elemental sulfur to a temperature of at least about 100° C.

7. The process according to claim 1 wherein said heating step further comprises heating the elemental sulfur to a temperature of between about 100° C. to about 207° C.

8. The process according to claim 5 wherein said heating step further comprises heating the elemental sulfur to a temperature of between about 100° C. to about 207° C.

9. A process of treating elemental mercury within a soil comprising steps of:

heating a subsurface soil to a temperature sufficient to enhance vapor phase concentration of elemental mercury present within the soil;

using vapor extraction to remove vaporized elemental mercury from the soil;

introducing a vapor phase of elemental sulfur into the heated soil by passing heated air through a mixture of coarse sand and elemental sulfur, thereby distributing the elemental sulfur throughout the mercury contamination zone;

allowing the sulfur vapor to react with vapor phase elemental mercury to form a reaction product of a mercury sulfide;

cooling said soil and thereby precipitating the vapor phase sulfur within the soil;

allowing the precipitated sulfur to react with residual elemental mercury present within the soil thereby forming a reaction product of mercury sulfide.

10. A process of treating in-situ elemental mercury contamination within a soil comprising steps of:

introducing into a soil contaminated with mercury a sulfur vapor, the sulfur vapor formed by heating elemental sulfur present within an access well;

allowing the sulfur vapor to react with a vapor phase elemental mercury present in the soil to form a stable and nontoxic reaction product of mercury sulfide;

precipitating a portion of the sulfur vapor as elemental sulfur within the contaminated soil region;

reacting the precipitated elemental sulfur with residual elemental mercury present within the soil, thereby forming a reaction product, of a mercury sulfide.

11. The process according to claim 1 wherein said process comprises the additional step of reacting sulfur vapor introduced into the soil with a vapor phase of elemental mercury present within the soil.