Patent ID: 7309436

Claim:
A method for removing perchlorate ion contamination from a perchlorate-ion-contaminated water stream comprising: a. obtaining a plurality of at least 6 vessels each substantially filled with a bed of an ion exchange resin having affinity for perchlorate ions, b. feeding said perchlorate-contaminated water stream over the resin in a substantial proportion but not all of the plurality of vessels, said substantial proportion of vessels operating in parallel to one another thereby removing perchlorate ion from the water stream and generating reduced perchlorate content product water streams and loading the resin beds in the substantial proportion of the plurality of vessels with perchlorate ions, c. periodically removing from service a subset of the vessels employed in step b, said subset of vessels containing resin that has been loaded with perchlorate in step b and replacing this subset with a similar subset of vessels taken from those vessels obtained in step a, but not employed in step b, d. either replacing in the plurality of vessels those vessels removed from service in step c with an equivalent number of equivalent replacement vessels having fresh ion exchange resin or replacing the ion exchange resin in those vessels removed from service in step c with fresh replacement ion exchange resin and returning the vessels with the fresh replacement ion exchange resin into the plurality of vessels, e. disposing to the perchlorate-loaded resin present in those vessels removed from service in step c, and f. continuing step b while periodically repeating steps c and d at least until all of the plurality of vessels have either been replaced or had their resin replaced.