Abstract: A method and apparatus for selectively recovering ions from an aqueous solution and producing deionized water for reuse. When used in a nickel plating process, a rinse water stream is passed through a first cation removing assembly that contains an ion exchange media having a greater affinity for nickel ions than for most or all other ions present in the system. Rinse water processed by the first cation removing assembly is conveyed to a second cation removing assembly and then to an anion removing assembly so that deionized water is produced and is then returned to a rinse bath. Rinse water is passed through the first ion exchange media until substantially all of the ion exchange sites hold a nickel ion. The other cations in the rinse water are captured by the second cation assembly. The first cation assembly is regenerated using a regeneration solution compatible with the plating bath.

Abstract: A water softening apparatus and method for reducing odor in, and improving the taste of, problem water, including a pair of treatment tanks and a control valve assembly for determining which tank is on-line, and which tank is off-line, and for controlling the regeneration of the off-line tank. An exhausted tank is taken off-line and partially regenerated by communicating a regeneration solution from a reservoir to the tank and passing the solution through a resin compartment after which the solution is discharged to drain. After a predetermined quantity of regeneration solution is passed through the tank, the resin compartment is slowly rinsed using treated water from the on-line tank. Prior to fully rinsing the off-line tank, the fluid flow is terminated leaving a diluted regeneration solution in the off-line tank thereby keeping the off-line tank in a "high solids" condition.