The present invention relates to a method for electrochemical purification of an aqueous solution comprising the steps of: providing a cathode and an anode to an aqueous solution, wherein said aqueous solution comprises soluble ions of at least one toxic heavy metal and wherein said cathode comprises an outer surface, which outer surface comprises a noble metal; applying an absolute potential to said cathode and wherein said absolute potential of said cathode drives the formation of an alloy comprising said noble metal and said at least one toxic heavy metal.