Treatment of liquids containing complexed heavy metals and complexing agents

A method of separating alkali metal salt by-products of an electroless copper deposition bath from an alkanolamine complexing agent and a complex species of copper complexed with an alkanolamine complexing agent in an alkaline electroless copper deposition bath, said method comprising:

• a. lowering the pH of said alkaline bath or alkaline effluent thereof to less than 11, to render said alkanolamine-complexed copper and said alkanolamine complexing agent extractable by an ion exchange medium;
• b. contacting the pH-adjusted bath liquid of step (a) with an ion exchange medium capable of extracting said alkanolamine-complexed copper and said alkanolamine complexing agent from the pH-adjusted bath liquid, said ion exchange medium being selected from the group consisting of cation exchange resins and chelating exchange resins;
• c. removing from said exchange medium a bath liquid comprises alkali metal salt by-products and which is substantially free of said alkanolamine-complexed copper and said alkanolamine complexing agent;
• d. removing said alkanolamine-complexed copper and said alkanolamine complexing agent from the exchange medium, and
• e. returning said alkanolamine-complexed copper and said alkanolamine complexing agent to an alkaline electroless metal deposition bath.

A method of separating alkali metal salt by-products of an electroless metal deposition bath from an alkanolamine complexing agent and a complex species of a heavy metal complexed with an alkanolamine complexing agent in an alkaline electroless metal deposition bath, said method comprising:

• a. lowering the pH of said alkaline bath or alkaline effluent thereof to render said alkanolamine complexed heavy metal and said alkanolamine complexing agent extractable by an ion exchange medium;
• b. contacting the pH-adjusted bath liquid of step (a) with an ion exchange medium capable of extracting said alkanolamine-complexed heavy metal and said alkanolamine complexing agent from the pH-adjusted bath liquid;
• c. removing from the exchange medium a bath liquid which comprises said alkali metal salt by-products and which is substantially free of said alkanolamine-complexed heavy metal and said alkanolamine complexing agent;
• and
• d. removing said alkanolamine-complexed heavy metal and said alkanolamine complexing agent from the exchange medium.

A method of treating an aqueous alkaline solution comprising an alkanolamine complexing agent and a heavy metal complexed with an alkanolamine complexing agent, said method comprising:

• a. lowering the pH of said alkaline solution to render the alkanolamine-complexed heavy metal and the alkanolamine complexing agent extractable by an ion exchange medium;
• b. contacting the pH-adjust solution of step (a) with an ion exchange medium capable of extracting said alkanolamine-complexed heavy metal and said alkanolamine complexing agent from the pH-adjusted bath liquid;
• c. discharging from the ion exchange medium a liquid which is substantially free of said alkanolamine-complexed heavy metal and said alkanolamine complexing agent;
• an
• d. regenerating the ion exchange medium.