Method for removing metals from a citric acid cleaning solution

摘要

A method for removing accumulated metals from a cleaning solution is provided. After removal of the metals, the cleaning solution can be discharged or recycled. The process manipulates the pH levels of the solution as a means of precipitating solids. Preferably a dual phase separation at two different pH levels is utilized. The cleaning solution may be a chelating solution, in particular a citric acid solution. After dual phase separation including filtering, the collected filtrate is preferably polished with a cationic ion exchange resing.