| 摘要 |
659,494. Electro-dialytic purification of liquids. NEDERLANDSE CENTRALE ORGANISATIE VOOR TOEGEPAST. NATUURWETEN-SCHAPPELIJK, ONDERZOEK. Feb. 10, 1949, No. 3708. Convention date, March 19, 1948. [Class 41] A process for the recovery of products which do not dialyse or dialyse only slowly from a liquid contaminated with inorganic substances, comprises subjecting the liquid to electrodialysis under vigorous agitation, while controlling the pH value of the liquid by washing at a controlled rate the anode chamber with a dilute solution of an acid and/or a neutral reacting electrolyte and the cathode chamber with a dilute solution of a mixture of a base and a neutral reacting electrolyte, or by washing at a controlled rate the anode chamber with a dilute solution of a mixture of an acid and a neutral reacting electrolyte and the cathode chamber with a dilute solution of a base and/or a neutral reacting electrolyte, the recovery of the products being completed by concentration, precipitation, or the application of other chemical and physical means. Examples are given of (1) the treatment of unpurified saltedout pepsin in which a solution of sulphuric acid and sodium sulphate was used as anodic washing liquid and a solution of sodium hydrate and sodium chloride was used as the cathodic washing liquid; and (2) the treatment of sugar syrup, the anodic washing liquid containing sulphuric acid and potassium sulphate and the cathodic washing liquid containing potassium hydrate. The process of the invention may be combined with other methods, for example acid or alkali may be added to the liquid under treatment, to assist in keeping the pH value constant. |
