L-色氨酸和L-苯丙氨酸在732树脂上的吸附平衡

Adsorption equilibrium of L-tryptophan and L-phenylalanine on 732 cation-exchange resins in a constant-temperature bath

研究了L-色氨酸和L-苯丙氨酸在732阳离子交换树脂上的单组分等温吸附平衡,分别采用Freundlich方程和Langmuir方程拟合吸附平衡数据.料液初始pH值介于3.5～6.5时,pH值对平衡吸附量影响不大,而料液中过多H+存在会降低氨基酸在树脂上的吸附量.当温度处于25～40℃范围,随着温度的升高,树脂的吸附量略有下降.在不同的pH和温度下,分别用Freundlich方程拟合L-色氨酸和L-苯丙氨酸平衡数据,其平均相对误差在3.63%～4.93%范围.

The adsorption equilibrium of L-tryptophan or L-phenylalanine on 732 cation-exchange resins in a constant-temperature bath was investigated.The adsorption equilibrium was represented with the Freundlich and the Langmuir isotherms.The effect of pH values on the amount of adsorption was not significant when the initial pH value of the feed was between 3.5 and 6.5.The exchanging capability of the resin was reduced due to the excess of H＋,when the initial pH value was lower than 2.0 and when the temperature was 25~40 ℃.The mean relative errors of L-tryptophan and L-phenylalanine predicted by the Freundlich equation were between 3.63% and 4.93% under different pH values and temperatures,respectively.