Fan Yiang, Wu Yunhai, Fang Peng, Ming Zhu
Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, Hohai University, 1st Xikang Road, Nanjing 210098, China E-mail:
College of Environment, Hohai University, 1st Xikang Road, Nanjing 210098, China.
Water Sci Technol. 2017 Jan;75(1-2):75-83. doi: 10.2166/wst.2016.491.
We compared the adsorption efficiency of phosphates onto Ca-alginate immobilized yeast and freely suspended yeast under different conditions of pH and temperature. The results clearly demonstrated that the adsorption efficiency onto Ca-alginate immobilized yeast was better than that of freely suspended yeast, and reached a maximum at pH 9.17 and 35 °C. Scanning electron microscopy was used to characterize the morphology of Ca-alginate immobilized yeast. Fitting the adsorption equilibrium data to existing models showed that the Freundlich isotherm model described the process better than the Langmuir model, and the process of adsorption followed pseudo-first-order kinetics. During the initial period of experiment, external diffusion was a key rate-controlling step, and intraparticle diffusion also contributed to the mass transport. The thermodynamic properties (Gibbs free energy change of -15.143 kJ/mol, enthalpy change of 274.118 kJ/mol, and entropy change of 290 J/(mol K)) indicated that the adsorption process was endothermic.
我们比较了在不同pH值和温度条件下，磷酸盐在海藻酸钙固定化酵母和自由悬浮酵母上的吸附效率。结果清楚地表明，海藻酸钙固定化酵母的吸附效率优于自由悬浮酵母，且在pH 9.17和35℃时达到最大值。利用扫描电子显微镜对海藻酸钙固定化酵母的形态进行了表征。将吸附平衡数据与现有模型拟合表明，Freundlich等温线模型比Langmuir模型能更好地描述该过程，且吸附过程遵循准一级动力学。在实验初期，外部扩散是关键的速率控制步骤，颗粒内扩散也对传质有贡献。热力学性质（吉布斯自由能变化为-15.143 kJ/mol，焓变为274.118 kJ/mol，熵变为290 J/(mol·K)）表明吸附过程是吸热的。
