一种球形木质素吸附剂对L-天门冬氨酸的吸附行为研究

以硫酸盐木质素为原料,利用反相悬浮技术制备出球形木质素吸附剂.通过静态吸附试验,研究了球形木质素吸附剂对L-天门冬氨酸的吸附动力学和热力学特性,探讨了pH对吸附过程的影响.结果表明,当溶液pH值为3.0时,SLA的平衡吸附容量为518.0mg/g,球形木质素吸附剂对L-天门冬氨酸的吸附速率同时受液膜扩散和颗粒内扩散过程控制.吸附符合Langmuir和Freundlich等温吸附方程.且焓△H-16.81kJ/mol,表明该吸附反应是以吸热的化学吸附过程为主,活化能Ea=3.3406kJ/mol,说明球形木质素吸附剂的吸附过程是以颗粒内扩散为主.

ADSORPTION BEHAVIORS OF L-ASPARTIC ACID ON A SPHERICAL LIGNIN ADSORBENT

A spherical lignin adsorbent was prepared by applying the reverse-phase suspension technique with raw material of lignin sulphate.Then the study regarding the adsorption kinetics and thermodynamics of L-aspartic acid on the spherical lignin adsorbent was carried out through static experiments.The effect factors,i.e.,solution pH and temperature etc.,were also optimized.The results indicated that the equilibrium adsorption capacity could reach 518mg/g under 3.0 of solution pH.And,the adsorption rate of L-aspartic acid on the spherical lignin adsorbent was simultaneously controlled by the liquid film diffusion and the intraparticle diffusion.The adsorption process could correspond with the Langmuir and Freundlich adsorption isotherm,Additionally,the enthalpy(?H) value was 16.81kJ/mol indicating adsorption process belonged to the endothermic chemical adsorption process.And,the activation energy Ea=3.3406kJ/mol indicated that the intraparticle diffusion was predominant during the adsorption process.