Water-soluble polymers for recovery of metal ions from aqueous streams
AssigneeThe Regents of the University of California Office of Technology Transfer
InventorsBarbara F. Smith, Thomas W. Robison
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Abstract
A process of selectively separating a target metal contained in an aqueous solution by contacting the aqueous solution containing a target metal with an aqueous solution including a water-soluble polymer capable of binding with the target metal for sufficient time whereby a water-soluble polymer-target metal complex is formed, and, separating the solution including the water-soluble polymer-target metal complex from the solution is disclosed.
Claims33
A process of separating selected metal ions from an aqueous solution comprising:
- contacting an aqueous solution containing selected metal ions with a reaction solution under conditions and for a period of time effective to form a water-soluble polymer-metal complex, the reaction solution including an effective amount of a water-soluble polymer having nitrogen-, oxygen-, or sulfur-containing groups capable of binding the selected metal ions, said water-soluble polymer having been pre-purified so as to have polymer molecule sizes capable of being retained by a membrane with a molecular weight cutoff value of a first preselected level and characterized as essentially free of polymer molecule sizes capable of passing through a membrane with a molecular weight cutoff value of a second preselected level, said second preselected level being smaller than said first preselected level;
- and, treating the aqueous solution by membrane separation means effective to separate water and low molecular weight materials having a molecular weight of less than said second preselected level from the aqueous solution while retaining a concentrated aqueous solution including materials having sizes capable of being retained by a membrane with a molecular weight cutoff value of greater than said second preselected level, said materials having sizes capable of being retained by a membrane with a molecular weight cutoff value of greater than said second preselected level including said water-soluble polymer and said water-soluble polymer-metal complex.
A process of selectively separating a target metal contained in an aqueous solution further including competing ions, wherein said target metal includes trivalent actinide metal ions and said competing ions include trivalent lanthanides, comprising:
- contacting said aqueous solution with a reaction solution including an effective amount of a water-soluble polymer having nitrogen-, oxygen- or sulfur-containing groups capable of binding the target metal without binding said competing ions for a time effective to form a water-soluble polymer-trivalent actinide metal complex;
- and,
- separating said water-soluble polymer-trivalent actinide metal complex from said aqueous solution including said trivalent lanthanides.
A process of separating selected metal ions from an aqueous solution comprising:
- contacting an aqueous solution containing selected actinide metal ions with a reaction solution under conditions and for time effective to form a water-soluble polymer-metal complex, the reaction solution including an effective amount of a water-soluble polymer having nitrogen-, oxygen-, or sulfur-containing groups capable of binding the selected metal ions, said water-soluble polymer having been pre-purified so as to have polymer molecule sizes capable of being retained by a membrane with a molecular weight cutoff value of a first preselected level and characterized as essentially free of polymer molecule sizes capable of passing through a membrane with a molecular weight cutoff value of a second preselected level, said second preselected level being smaller than said first preselected level;
- and,
- treating the aqueous solution by membrane separation means effective to separate water and low molecular weight materials having a molecular weight of less than said second preselected level from the aqueous solution while retaining a concentrated aqueous solution including materials having sizes retained by a membrane with a molecular weight cutoff value of greater than said second preselected level, said materials having sizes retained by a membrane with a molecular weight cutoff value of greater than said second preselected level including said water-soluble polymer and said water-soluble polymer-metal complex.
Dependencies are inferred from the claim text.