Electrochemical growth kinetics of Leptospirillum ferrooxidans through oxidation of Fe~(2+)

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(Fe~(3+))/c(Fe~(2+))].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/m~3 the oxidation of ferrous ion increases,however the increase of ferrous ion concentration up to 5kg/m~3 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 1.25×10~8cells/dm~3.Based on the ferrous ion oxidation and redox potential the growth kinetics models were established and the value of activation energy(E_a),frequency factor(K_0),saturation constant(K_m),and substrate inhibition coefficient(K_i) were determined.The kinetics model is well in coincidence to the experiments results.