Abstract: The present invention relates to an electrowinning cell adapted to recover metal ions from a solution as their corresponding elementary metals. The electrowinning cell includes a reservoir and a filter in fluid communication with the reservoir. The filter is operative to receive a solution containing metal ions from a location proximate to the cathode and to retain a first portion of the solution having a first concentration of metal ions and to remove a second portion of the solution having a second concentration of metal ions lower than the first concentration. The electrowinning cell additionally includes return means operative to return the first portion of the solution to the reservoir. The present invention also relates to a method of concentrating metal ions in a solution for use in an electrochemical cell and to a system for reducing metal ions in a solution to their corresponding elementary metals.

Abstract: The present invention provides a method for selectively removing metal ions of interest from a solution (12), such as the wastewater from a chemical mechanical polishing process. The method comprises contacting a solution (12) containing solid particles, an oxidizing agent and a first concentration of the metal ions with an ion-exchange resin (20), such as a crosslinked poly-4-vinylpyridine resin, that is resistant to damage by the oxidizing agent and that is operative when in contact with the solution (12) to exchange selected ones of the metal ions in the solution for selected preferred ions in the ion-exchange resin thereby to produce a treated solution (22) having a second concentration of the metal ions that is lower than the first concentration. The present invention also relates to an apparatus (100) and system (500) for use with the method of the present invention.

Abstract: Wastewater discharge, which is generated in an ion exchange regeneration system having a cation exchange bed and an anion exchange bed, is minimized by circulating a displacement rinse through a cation exchange bed, saving an effluent of the displacement rinse to be used as a regenerant solution in a subsequent cycle, circulating the remaining rinse in the cation exchange bed through an anion exchange bed that has been exhausted by service flow, circulating a displacement rinse through the anion exchange bed, and circulating a final rinse through the cation and anion exchange beds. The volume of wastewater discharge can be reduced to a degree of approximately 80-90% of a typical conventional system, i.e., waste water discharge can be reduced to 1-2 bed volumes. Storage tanks, automation valves, etc. can be eliminated while high reduction of wastewater discharge is effected.

Abstract: A method for minimizing wastewater discharge generated in an ion exchange regeneration system having a cation exchange bed and an anion exchange bed, which method is characterized in that all of the segments of regenerant and displacement rinse are recirculated in a common loop, and shifted forward by one position, whereby the first segment is discarded in the subsequent cycle, and the last segment in the subsequent cycle is provide by fresh rinse, while chemicals are added as necessary, and in final rinse cycle, rinse flows through the cation exchange bed and the anion exchange bed in series, and recirculates in a loop, thereby eliminating over 90% of waste.

Abstract: A method for minimizing wastewater discharge generated in an ion exchange regeneration system having a cation exchange bed and an anion exchange bed, which method is characterized in that all of the segments of regenerant and displacement rinse are recirculated in a common loop, and shifted forward by one position, whereby the first segment is discarded in the subsequent cycle, and the last segment in the subsequent cycle is provide by fresh rinse, while chemicals are added as necessary, and in final rinse cycle, rinse flows through the cation exchange bed and the anion exchange bed in series, and recirculates in a loop, thereby eliminating over 90% of waste.