Process using rare earths to remove oxyanions from aqueous streams
First Claim
1. A process for removing oxyanions of an element having an atomic number selected from the group consisting of 5, 13, 14, 22 to 25, 31, 32, 40 to 42, 44, 45, 49 to 52, 72 to 75, 77, 78, 82, 83 and 92 from an aqueous feed containing one or more of said oxyanions, which process comprises contacting said aqueous feed with a sorbent comprising one or more rare earth compounds to remove one or more of said oxyanions from said feed and thereby produce an aqueous fluid having a reduced concentration of said oxyanions as compared to said feed, wherein said rare earth compound or compounds are not supported on particulate solids having a cation exchange capacity for said rare earth compound or compounds greater than 20 milliequivalents per 100 grams.
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Accused Products
Abstract
Oxyanions of various contaminant elements, such as chromium, antimony, molybdenum, tungsten, vanadium and uranium, are removed from water and other aqueous feeds by treating the feed with (1) a sorbent comprising one or more rare earth compounds, usually mixed or supported on particulate solids having a cation exchange capacity less than 20 milliequivalents per 100 grams or (2) an aqueous solution of one or more soluble rare earth compounds.
34 Citations
33 Claims
- 1. A process for removing oxyanions of an element having an atomic number selected from the group consisting of 5, 13, 14, 22 to 25, 31, 32, 40 to 42, 44, 45, 49 to 52, 72 to 75, 77, 78, 82, 83 and 92 from an aqueous feed containing one or more of said oxyanions, which process comprises contacting said aqueous feed with a sorbent comprising one or more rare earth compounds to remove one or more of said oxyanions from said feed and thereby produce an aqueous fluid having a reduced concentration of said oxyanions as compared to said feed, wherein said rare earth compound or compounds are not supported on particulate solids having a cation exchange capacity for said rare earth compound or compounds greater than 20 milliequivalents per 100 grams.
- 23. A process for removing oxyanions of an element selected from the group consisting of bismuth, manganese, molybdenum, antimony, lead, uranium, and hafnium from an aqueous feed containing one or more of said oxyanions, which process comprises contacting said aqueous feed with a sorbent comprising one or more rare earth compounds to remove one or more of said oxyanions from said feed and thereby produce an aqueous fluid having a reduced concentration of said oxyanions as compared to said feed.
- 28. A process for removing oxyanions of an element having an atomic number selected from the group consisting of 5, 13, 14, 22 to 25, 31, 32, 40 to 42, 44, 45, 49 to 52, 72 to 75, 77, 78, 82, 83 and 92 from an aqueous feed containing one or more of said oxyanions, which process comprises contacting said aqueous feed with an aqueous solution of one or more soluble rare earth compounds to precipitate one or more of said oxyanions from said feed and thereby produce an aqueous fluid having a reduced concentration of said oxyanions as compared to said feed.
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32. A process for removing oxyanions of an element having an atomic number selected from the group consisting of 5, 13, 14, 22 to 25, 31, 32, 40 to 42, 44, 45, 49 to 52, 72 to 75, 77, 78, 82, 83 and 92 from an aqueous feed containing one or more of said oxyanions, which process comprises contacting said aqueous feed with a sorbent comprising one or more rare earth compounds to remove one or more of said oxyanions from said feed and thereby produce an aqueous fluid having a reduced concentration of said oxyanions as compared to said feed.
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33. A device for removing oxyanions from drinking water comprising:
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(a) an inlet communicating with a source of said drinking water; (b) a vessel containing a sorbent comprising one or more rare earth compounds supported on or mixed with particulate solids having a cation exchange capacity less than 20 milliequivalents per 100 grams, wherein said vessel has an entry portion and an exit portion and said entry portion communicates with said inlet; and (c) an outlet communicating with said exit portion of said vessel.
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Specification