研究了淀粉微球(CSM)对Co^2+的吸附行为,分析了其吸附热力学性质和动力学特性,初步探讨了吸附机理。结果表明,在研究的浓度范围内,CSM对Co^2+吸附行为符合Langmuir和Freundlich等温方程,不同温度下,CSM吸附Co^2+的吸附焓变ΔH、吸附自由能变ΔG、吸附熵变ΔS均为负值,表明吸附是一个自发的、放热的过程,降低温度有利于吸附;CSM主要通过物理吸附方式吸附Co^2+,吸附同时受液膜扩散和颗粒内扩散过程控制,液膜扩散为吸附过程的主控步骤。
The adsorption behavior of starch microspheres(CSM)for Co^2+ was investigated at different temperatures.The thermodynamics parameters in adsorption process were calculated and the property of adsorption kinetics was studied,the mechanism of adsorption was preliminarily discussed.The results show that the adsorption characteristic of CSM for Co^2+ is adapted to langmuir and Freundlich adsorption isotherm equation,the adsorption thermodynamic of CSM for Co^2+ including enthalpy changeΔH,free energy change ΔG and entropy change ΔS,are all negative when temperature were in the range of 308 to 328K,which indicates the adsorption is a spontaneous and exothermic process of decreased entropy,and the decrease of temperature would benefit the adsorption.The CSM absorb Co^2+ by means of physical adsorption.the adsorption rate is mainly controlled by the external diffusion and the particle diffusion,and the external diffusion is the main rate-controlling step.