Method of removing Cr(VI) ions from an aqueous electrolyte solution

A device for the electrochemical machining of a workpiece, wherein the device comprises:

• a work table adapted to support the workpiece to be machined;
• an electrode tool;
• a storage tank for feeding an electrolyte solution;
• a feed line for feeding the electrolyte solution from the storage tank to the workpiece to be machined by at least one pump;
• an intermediate container for collecting the electrolyte solution which has been fed to the workpiece;
• a return line for recycling the electrolyte solution to the storage tank from the intermediate container, and
• optionally, a bypass line for circulating the electrolyte solution via the intermediate container to the storage tank bypassing the workpiece,
• and wherein in at least one of the feed line, the return line and the bypass line an ion exchanger with an ion exchange resin loaded with Fe(II) ions is positioned.