A halogen atom is given to the object metal from the halogenated hydrocarbons, and the metal halide is formed. The metal halide is converted to an ion pair of a metal polyhalide anion complex and an alkylammonium cation by the action of the cationic surfactant, and the metal is dissolved ...
a softener operative in parallel to the cation exchanger, and treating the partial streams treated by the cation exchanger and the softener by at least one anion exchanger operating in the OH mode, and wherein the water stream obtained from the pretreatment is fed into the reverse osmosis ...