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US 7,419,602 B2Granted
Selenium removal from water
AssigneeConocoPhillips Company
InventorsRoosevelt Alexander, Charles J. Lord, Steven C. Mitchell
Life of this patent
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Abstract
A process for removing selenium from a water stream, in particular a waste water stream, by: 1) the addition thereto of a ferric salt, followed by 2) the addition of a cupric salt and pH adjustment to a pH value in the range of from about 6.5 to about 8.0, thereby forming a copper-and-selenium-containing precipitate, and 3) removing the copper-and-selenium-containing precipitate to thereby form a treated water stream, is disclosed. The optional precipitation and removal of excess copper ions is also disclosed.
Claims17
A process comprising:
- adding a ferric salt to a feed stream comprising water and selenocyanate to thereby form a first intermediate stream, wherein at least about 0.003 milligrams of said ferric salt are added to said feed stream;
- adding a cupric salt to said first intermediate stream to thereby form a second intermediate stream;
- adjusting the pH of said second intermediate stream to a pH value in the range of from about 6.5 to about 8.0 in order to maximize the reaction of said cupric salt with said selenocyanate to thereby form a copper-adding a polymer to said second intermediate stream for flocculation with said copper-and-selenium-containing precipitate thereby forming a third intermediate stream comprising floccules of said polymer and said copper-and-selenium-containing precipitate;
- and-selenium-containing precipitate;
- and
- removing said floccules-and-selenium-containing floccules from said third intermediate stream to thereby form a treated water stream.
3 more elements
Dependencies are inferred from the claim text.