Chalcogenide compounds for the remediation of nuclear and heavy metal wastes

1. A method comprising:

exposing a fluid sample comprising a metal to a chalcogenide compound having the formula (A x B x ′)M y Q z , where A is an alkali cation or an alkylammonium cation; B is an alkaline earth cation; M is Sn, Zn, P, Cu or Sb; and Q is S or Se, wherein the values of x, y and z can be the same or different; x, x′ and y can range, independently, from 0 to 9, provided that if one of x and x′ is zero, the other is not; and z can range from 1 to 25, whereby the chalcogenide compound absorbs the metal; and

removing the absorbed metal from the fluid sample, wherein the metal is an elemental metal.

2. The method of claim 1 , wherein the metal is mercury.

3. The method of claim 2 , wherein the fluid sample comprises a liquid hydrocarbon.

4. The method of claim 3 , wherein the metal is mercury and the liquid hydrocarbon is petroleum or crude oil.

5. The method of claim 1 , wherein the fluid sample comprises natural gas.

6. A method comprising:

exposing a fluid sample comprising a metal to a chalcogenide compound having the formula A x M y Q z , wherein A is an alkali cation; M is Sn, Zn, P, Cu or Sb; and Q is S or Se, wherein x and y are in the range from 1 to 9, and z is in the range from 1 to 25, whereby the chalcogenide compound absorbs the metal; and

removing the absorbed metal from the fluid sample.

7. The method of claim 6 , wherein x is 1 or 2, M is Sn or Sb; y is 2, 4 or 8; and z is in the range from 6 to 23.

8. The method of claim 6 , wherein the chalcogenide compound has a formula selected from the group consisting of A 2 Sn 4 S 9 , A 2 Sn 2 S 5 , A 2 Sn 3 S 7 , and A 2 Sb 4 S 7 , and A is selected from the group consisting of Li, Na, K, Rb, and Cs.

9. The method of claim 6 , wherein the metal comprises Cs or Sr radionuclide ions.

10. The method of claim 6 , wherein at least 90 percent by weight of the metal is removed from the fluid sample.

11. The method of claim 6 , wherein at least 98 percent by weight of the metal is removed from the fluid sample.

12. A method comprising:

exposing a fluid sample comprising a metal to a chalcogenide compound having the formula B x M y Q z , wherein x and y are in the range from 1 to 9 and z is in the range from 1 to 25, where B is an alkaline earth cation; M is Sn, Zn, P, Cu or Sb; and Q is S or Se, wherein the values of x, y and z can be the same or different, whereby the chalcogenide compound absorbs the metal; and

removing the absorbed metal from the fluid sample.

13. The method of claim 12 , wherein x is 1 or 2, M is Sn or Sb, y is 2 or 4, and z is in the range of 5 to 25.

14. A method comprising:

exposing a fluid sample comprising a metal to a chalcogenide compound selected from the group consisting of A 2 Sn 4 S z , BSnS z , and A 4 B 2 Sn 4 S 12 , where A is an alkali cation or an alkylammonium cation; B is an alkaline earth cation; and where z is in the range from 4 to 25, whereby the chalcogenide compound absorbs the metal; and

removing the absorbed metal from the fluid sample.

15. A method comprising:

exposing a fluid sample comprising an elemental metal to a chalcogenide compound having the formula (A x B x ′)M y Q z , where A is an alkali cation or an alkylammonium cation; B is Ca, Sr or Ba; M is Sn, Zn, P, Cu or Sb; and Q is S or Se, wherein the values of x, y and z can be the same or different; x, x′ and y can range, independently, from 0 to 9, provided that if one of x and x′ is zero, the other is not; and z can range from 1 to 25, whereby the chalcogenide compound absorbs the elemental metal; and

removing the absorbed elemental metal from the fluid sample.

16. The method of claim 15 , wherein the fluid sample comprises both ionic and elemental metal and further wherein ionic and elemental metal are removed simultaneously from the fluid sample.