Perchlorate Destruction

Abstract

Perchlorate is removed and effectively destroyed in devices and methods that employ a eluting solvent in which the anion of an acid solubilizes Ti (III), which may be electrochemically generated or added in situ. Using such solvents, destruction of perchlorate is unexpectedly and several orders of magnitude faster than using solvents without solubilizing acids. In most preferred aspects, the solubilizing acid is methane sulfonic acid and/or sulfamic acid, and Ti (III) is electrochemically generated. Perchlorate destruction will then result in formation of Ti (IV), which may be present in the eluent in a subsequent elution.

1 . A method of regenerating an anion exchange resin to which perchlorate is bound comprising a step of contacting the resin with an eluent that includes titanium ions and that further comprises an additive that (a) increases solubility of the titanium ions relative to the same eluent without the additive and (b) increases perchlorate conversion to chloride relative same eluent without the additive. 
   
   
       2 . The method of  claim 1  wherein the additive is selected from the group consisting of an alkylsulfonic acid, methanesulfamic acid, and a halogenated alkylsulfonic acid. 
   
   
       3 . The method of  claim 1  wherein the titanium ions are titanium (IV) ions. 
   
   
       4 . The method of  claim 1  wherein the titanium ions are titanium (III) ions. 
   
   
       5 . The method of  claim 1  wherein the exchange resin further comprises nitrate bound to the exchange resin. 
   
   
       6 . A method of concurrent perchlorate and nitrate destruction comprising reacting the perchlorate and the nitrate with titanium (III) in a solvent that comprises the titanium (III) and an additive that (a) increases solubility of the titanium ions relative to the same solvent without the additive and (b) increases perchlorate conversion to chloride relative same solvent without the additive. 
   
   
       7 . The method of  claim 6  wherein the additive is selected from the group consisting of an alkylsulfonic acid, methanesulfamic acid, and a halogenated alkylsulfonic acid. 
   
   
       8 . The method of  claim 6  wherein the destruction is performed on a column. 
   
   
       9 . The method of  claim 8  wherein the ion exchange resin is a perchlorate selective ion exchange resin. 
   
   
       10 . The method of  claim 6  wherein the titanium (III) is electrochemically generated from titanium (IV). 
   
   
       11 . A method of removing perchlorate and nitrate from water, comprising:
 adsorbing the perchlorate and the nitrate onto an ion exchange resin;   eluting the perchlorate and the nitrate from the ion exchange resin;   using Ti (IV) in a solution to thereby destroy the perchlorate and the nitrate; and   wherein the solution further comprises an additive that (a) increases solubility of the Ti (IV) relative to the same eluent without the additive and (b) increases perchlorate conversion to chloride relative same eluent without the additive.   
   
   
       12 . The method of  claim 11  wherein the Ti (IV) is electrochemically generated. 
   
   
       13 . The method of  claim 11  wherein the perchlorate and the nitrate are reabsorbed onto a second ion exchange resin prior to the step of using the Ti (IV). 
   
   
       14 . The method of  claim 11  wherein the additive is selected from the group consisting of an alkylsulfonic acid, methanesulfamic acid, and a halogenated alkylsulfonic acid.