电化学动力学
(1. 北京科技大学 冶金与生态工程学院，教育部生态与循环冶金重点实验室， 北京 100083;
2. 北京有色金属研究总院， 北京 100088)
摘 要: 研究Leptospirillum ferrooxidans溶液氧化还原电位φ与Fe2+氧化的内在联系， 得到φ随溶液ln［c(Fe3+)/c(Fe2+)］的增加呈线性增长关系； 研究Fe2+、 细菌浓度、 温度变化时Fe2+氧化反应速率的变化规律。 在给定条件下， 当溶液中Fe2+浓度较低时， 随着Fe2+浓度的上升， Fe2+的氧化速率加快， 而当Fe2+浓度在5 kg/m3以上时， Fe2+浓度的增加不但不会促使氧化速率加快， 反而会抑制Fe2+的氧化； 细菌浓度的增加， 氧化速率随之上升， 当细菌浓度在1.25×108 cells/dm3以上时， 氧化速率随细菌浓度的增加有较大幅度的增长； 当温度在20~35 ℃范围时， 温度的升高会加快细菌氧化Fe2+的速率， 当温度再升高， 则会抑制Fe2+的氧化。 通过一系列电化学与生物化学分析， 导出了Leptospirillum ferrooxidan生长动力学方程， 并计算出活化能Ea、 频率因子K0、 表观饱和常数Km和单元附着系数K′i等动力学参数的值； 动力学模型能很好说明实验结果。
关键字: Leptospirillum ferrooxidans; 细菌浸出; 生物冶金; 混合电位; 动力学; 电化学
oxidation of Fe2+
（1. Ecology and Recycling Metallurgy Laboratory of National Education Ministry,
School of Metallurgy and Ecology Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. General Research Institute of Nonferrous Metals, Beijing 100083, China）
Abstract: The relatively relationship between solution rexdox potential and the ferrous iron oxidation rate was established, and it shows that the φ value increases linearly with ln［c(Fe3+)/c(Fe2+)］. All the ferrous ion, the bacteria cells concentration and temperature have apparent effect on the ferrous oxidation rate. When the concentration of ferrous is less than 5 kg/m3 the oxidation of ferrous ion increases, however the increase of ferrous ion concentration up to 5 kg/m3 would give inhibition of oxidation rate, as well as at the temperature range of 20 ℃ to 35 ℃, the increased temperature can enhance the ferrous ion oxidation, but when the temperature is above 40 ℃, the growth of bacteria inhibis and the oxidation decreases relatively. The increase of cells concentration of bacteria enhances the oxidation apparently especially when the concentration of cells increases to above 1.25×108 cells/dm3. Based on the ferrous ion oxidation and redox potential the growth kinetics models were established and the value of activation energy (Ea), frequency factor (K0), saturation constant (Km), and substrate inhibition coefficient (Ki) were determined. The kinetics model is well in coincidence to the experiments results.
Key words: Leptospirillum ferrooxidans; bioleaching; biohydrometallurgy; redox mixed potential; kinetics; electrochemistry
