D301-G大孔树脂吸附菊芋多糖色素机理探究

Adsorption Mechanism Research on Jerusalem artichoke Polysaccharide Pigment with D301-G Macroporous Resin

为了探究菊芋多糖提取液中色素杂质的去除效果,本文采用静态吸附法对六种大孔树脂进行了初步筛选,并研究了D301-G大孔树脂对菊芋多糖色素的静态吸附动力学、静态吸附模型及其吸附热力学,深入探讨了D301-G大孔树脂对菊芋多糖色素的吸附机理。结果表明,在相同的实验条件下,D301-G大孔树脂与其它树脂相比脱色效果最好,吸附菊芋多糖色素速率较快,多糖的损失率最小,脱色率可达到79.63%,多糖保留率为92.28%。此外D301-G大孔树脂对菊芋多糖色素的吸附过程符合准二级吸附动力学方程,主要受颗粒扩散阻力的影响。等温吸附实验表明,在293、303和313 K时Freundlich等温线模型较Langmuir模型更为准确地描述D301-G大孔树脂的吸附行为,它对色素分子的吸附可能是多分子层的。热力学方程表明D301-G大孔树脂吸附过程是一个吸热过程,吸附焓变ΔH> 0、吸附自由能变ΔG <0、吸附熵变ΔS> 0。

In order to explore the removal of pigment impurities in the extract of Jerusalem artichoke polysaccharide,a preliminary screening of six macroporous resins was carried out by static adsorption method. The static adsorption kinetics,adsorption model and adsorption thermodynamics of D301-G macroporous resin on Jerusalem artichoke polysaccharide pigment were studied to explore adsorption mechanism of D301-G resin. The results showed that,under the same experimental conditions,D301-G macroporous resin adsorbed Jerusalem artichoke polysaccharide pigment faster than other resins,and the loss rate of polysaccharides was the smallest. The decolorization rate of D301-G was 79.63% and the Jerusalem artichoke polysaccharide retention was 92.28%.The adsorption process conformed to the pseudo-second-order model,which was mainly affected by particle diffusion resistance.When D301-G macroporous resin was used at 293,303 and 313 K,compared with the Langmuir isotherm,it was more in line with the Freundlich isotherm model,and its adsorption of pigment molecules might be multi-molecular.The thermodynamic parameters were found to be ΔH > 0,ΔG < 0,ΔS > 0,a physical adsorption process that exhibited an endothermic.