The studies of acids and metal salts removal from rinsing water after metal etching are presented. It has been found that the highest desalination efficiency can be reached when the current density is slightly lower than the limiting current density value. Removal of the acids (hydrochloric and sulphuric) and iron salts amounted to 92-97%, and energy consumption ranged between 0.26 and 3.60 Wh/dm(3).