Mercury removal process
View Patent ↗A process for removing mercury from an aqueous stream using a supported selenium and sulfur material is disclosed.
1. A method for removing mercury from a feed stream comprising water and mercury which comprises:
relocating a composition recovered from a selenium removal treatment system used for removing selenium from an effluent stream, wherein said composition is relocated for contact with said feed stream to remove the mercury in solution with said water; and
contacting said feed stream with said composition comprising selenium, sulfur and a porous support for removal, by said composition, of at least a portion of the mercury in said feed stream resulting in a treated stream comprising less mercury than said feed stream.
2. The method of claim 1 wherein at least a portion of the selenium and sulfur of said composition are present as selenium sulfide.
3. The method of claim 1 wherein said composition comprises between about 2 and about 20 wt. % selenium.
4. The method of claim 1 wherein said composition comprises between about 5 and about 15 wt. % selenium.
5. The method of claim 1 wherein said composition comprises between about 8 and about 10 wt. % selenium.
6. The method of claim 1 wherein said feed stream is contacted with said composition at a temperature in the range of from about 20° C. to about 90° C.
7. The method of claim 1 wherein said feed stream is contacted with said composition at a temperature in the range of from about 40° C. to about 75° C.
8. The method of claim 1 wherein said feed stream is contacted with said composition at a temperature in the range of from about 50° C. to about 75° C.
9. The method of claim 1 wherein said feed stream is contacted with said composition at a pH between about 2 and about 11.
10. The method of claim 1 wherein said feed stream is contacted with said composition at a pH between about 3 and about 10.
11. The method of claim 1 wherein said feed stream is contacted with said composition at a pH between about 3 and about 7.
12. The method of claim 1 wherein said treated stream comprises at most about 30% of the mercury contained in said feed stream, on an elemental mercury basis.
13. The method of claim 1 wherein said treated stream comprises at most about 20% of the mercury contained in said feed stream, on an elemental mercury basis.
14. The method of claim 1 wherein said treated stream comprises at most about 10% of the mercury contained in said feed stream, on an elemental mercury basis.
15. The method of claim 1 wherein said porous support is selected from the group consisting of an inorganic oxide, carbon and combinations thereof.
16. The process of claim 1 wherein said porous support is selected from the group consisting of alumina, carbon and combinations thereof.
17. The process of claim 1 wherein said porous support is carbon.