Reverse Osmosis Separation of Some Monoamino Monocarboxylic Acids in Aqueous Solutions Using Cellulose Acetate Membrane
Journal of the Faculty of Agriculture Kyushu University
The reverse osmosis separation of some monoamino monocarboxylic acids (1.0x 10-3mol/Z) in single aqueous solutions was carried out by batch cell under an operating pressure of 20Kg/cm2.G at a temperature of 30°C. using DDS-cellulose acetate membrane. Taft's polar parameter (Jo*). Taft's steric parameter (-YE,) and nonpolar parameter (.ZS*) governing reverse osmosis separations of nonionized polar aliphatic and alicyclic organic compounds could be applied to amino acids whose substituents are
... posed of hydrocarbon, such as aliphatic amino acids and part of aromatic amino acids. These three parameters (.X6*, ZE,. ZS*) were correlated with polarity of covalent bond, molecular weight of substituent, and interaction energy of London-van der Waals dispersion force, respectively. As a result, these characteristic parameters were also applied to sulfurcontaining amino acids, aromatic amino acids, and hydroxy amino acids. The calculated values of rejection of amino acids based on these parameters agreed with observed values approximately. Also, the separation of monoamino monocarboxylic acids in binary aqueous solution system containing L-alanine (1.0~10-m ol/l) was carried out by reverse osmosis under the same operating conditions. As a result, preferential permeability of L-alanine was governed with Taft's polar parameter of added amino acids in the concentration range of added amino acids (<1.0x10-3mol/Z). in which the formation of adsorbed layer of added amino acids on the surface of membrane might be taken place.