| 摘要 |
A purification method by nanofiltration of an aqueous solution containing one or several sugars, multivalent cations, monovalent metallic cations, monovalent anions and multivalent inorganic anions and/or organic acid anions, characterized in that it comprises the following steps which consist in: (a) replacement of at least a part of the multivalent cations and/or the mineral multivalent anions and organic acid anions respectively with monovalent metal cations and/or monovalent anions in order to obtain an aqueous solution depleted in multivalent cations and/or multivalent inorganic anions and organic acid anions, and containing the monovalent metal cations and monovalent anions; (b) nanofiltration of the solution resulting from step (a) to obtain as a retentate, a sugary aqueous juice enriched in sugars, in multivalent cations and in multivalent inorganic anions and/or in organic acid anions, and as a permeate, an aqueous effluent enriched in monovalent anions and monovalent metal cations; (c) demineralization of at least a part of the retentate obtained in (b), with a cation-exchange resin of which the counter-ion is H+ and an anion-exchange resin of which the counter-ion is OH-, these reins thus charging themselves respectively in residual cations of the retentate; and (d) regeneration of the cation-exchange resin by means of an inorganic acid of which the anion is of the same type as the monovalent anions present in the initial aqueous solution, and on the other hand, the anion-exchange resin by means of an inorganic base of which the cation is the same type as the monvalent metal cations present in the initial aqueous solution, which produces regenerated exchange resins and two regeneration effluents mainly containing monovalent anions and monovalent metal cations. Also described is the use of the above method in the purification of a whey and a permeate resulting from the ultrafiltration of a whey, sugar beetroot juice, sugarcane juice, chicory juice or Jerusalem Artichokes. The whey, permeate or juice comprises Ca2+ and Mg2+ ions, Cl- anions, Na+ and K+ cations and anions selected mainly in the group consisting in the phosphate and sulphate anions, anions from organic acids and their mixtures. |
