Selective removal of copper or nickel from complexing agents in aqueous solution

摘要

A method is provided for selectively separating and removing complexed heavy metal ions, preferably copper or nickel, from complexing agents in aqueous solution and removing substantially all heavy metal ions while leaving complexing agent in said solution. In preferred embodiments, complexed copper or complexed nickel is selectively removed from aqueous effluent from electroless plating systems by passage through a bed of chelating ion-exchange resin having an iminodiacetic acid functionality. Substantially all copper or nickel will be removed from solution and retained in the resin bed and the complexing agent will pass through for conventional waste treatment or disposal. The copper or nickel is recovered by elution from the resin bed with an acid solution and may, if desired, be precipitated by addition of sodium hydroxide or the like and subsequently separated for recovery or disposal. An improved process for electroless disposition of copper, or nickel, which facilitates waste treatment or recovery of residual complexed copper or nickel ions from plating or effluent solutions is likewise provided in accordance with the invention.