废酵母菌吸附水中铜离子热力学及动力学研究

Thermodynamic and Kinetic Studies on the Waste Yeast Adsorbing Copper Ions in Wastewater

研究了应用低成本吸附剂废酵母菌经微波改性后去除溶液中的重金属铜离子。并研究了在pH值、温度、初始浓度、酵母菌吸附量等因素的影响下，废酵母菌对水中铜离子的吸附效率。研究结果表明，在pH为7．0、温度为328K、Cu^2＋初始浓度为40mg／L时，微波改性酵母菌的最大吸附容量为41．84mg／g。吸附过程符合Langmuir吸附等温模式。吸附过程的热力学常数△G0、△H0和AS0分别为-3．51254kJ／mol，3．29096kJ／mol和20．18146J／（mol·K）。表明废酵母菌对Cu^2＋的吸附是自发的、吸热反应。微波改性废酵母菌对Cu^2＋的吸附动力学模型能够较好地符合准二级动力学方程。

Low-cost sorbents were studied to replace current costly methods for removing heavy metals from solutions. Microwave modified yeast was tested as adsorbents for removing copper ions （Cu^2＋） from aqueous solutions. The highest Cu^2＋ adsorption capacity of the yeast could reach 41.84 mg/g for 40 mg/L initial Cu^2＋ concentration at pH 7.0 and 328 K. The adsorption data fitted with Langmuir model. Thermodynamic constants of the adsorption process A Go, A Ho and A So were evaluated to be -3.512 54 kJ/mol, 3.290 96 kJ/mol and 20.181 46 J/tool/K, respectively. It indicated that the Cu2. adsorption by waste yeast was a spontaneous and endothermic reaction. The kinetic model of the yeast adsorbing Cu^2＋ has well shown in agreement with quasisecondary kinetic equation.