Patent ID: 6908560

Claim:
A process for removing arsenic contamination from an arsenic-contaminated drinking water source additionally comprising feed water levels of at least one noncontaminant ion selected from the group consisting of chloride, sulfate and bicarbonate said process comprising a. passing the arsenic-contaminated drinking water over a bed of ion exchange resin under conditions whereby the resin selectively absorbs arsenic contamination from the drinking water thereby forming an arsenic-reduced drinking water product and a bed of arsenic-loaded ion exchange resin, b. halting the passing of drinking water over the bed of arsenic-loaded ion exchange resin, c. passing a regenerant solution over the bed of arsenic-loaded ion exchange resin, said regenerant solution comprising concentrated levels of said at least one noncontaminant ion said concentrated levels being related to one another as the feed water levels are related to one another, thereby displacing arsenic off of the ion exchange resin and forming a bed of regenerated ion exchange resin, the ions present on the regenerated resin being related to the feed water noncontaminant ion levels, and a spent regenerant solution, said spent regenerant solution containing an elevated level of arsenic, d. separating the spent regenerant solution from said regenerated ion exchange resin, e. treating the separated spent regenerant solution to selectively convert arsenic into an isolable form and to form a refreshed regenerant solution containing a reduced level of arsenic and concentrated levels of said at least one noncontaminant ion, f. isolating the isolable arsenic and g. recycling the refreshed regenerant solution to step c.