Regeneration of anion exchange resins by catalyzed electrochemical reduction
First Claim
1. A method for the regeneration of a strong-base anion exchange resin sorbed with perchlorate (ClO4−
- ) comprising;
addition of an aqueous complexed metal reducing agent selected from the group consisting of Ti(III) and Re(V) to convert perchlorate to chloride;
eluting the column with a dilute acid; and
optionally eluting the column with a solution of NaCl.
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Accused Products
Abstract
Anion exchange resins sorbed with perchlorate may be regenerated by a combination of chemical reduction of perchlorate to chloride using a reducing agent and an electrochemical reduction of the oxidized reducing agent. Transitional metals including Ti, Re, and V are preferred chemical reagents for the reduction of perchlorate to chloride. Complexing agents such as oxalate are used to prevent the precipitation of the oxidized Ti(IV) species, and ethyl alcohol may be added to accelerate the reduction kinetics of perchlorate. The regeneration may be performed by continuously recycling the regenerating solution through the resin bed and an electrochemical cell so that the secondary waste generation is minimized.
22 Citations
15 Claims
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1. A method for the regeneration of a strong-base anion exchange resin sorbed with perchlorate (ClO4−
- ) comprising;
addition of an aqueous complexed metal reducing agent selected from the group consisting of Ti(III) and Re(V) to convert perchlorate to chloride;
eluting the column with a dilute acid; and
optionally eluting the column with a solution of NaCl. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- ) comprising;
Specification