[Determination the parameters of bacteria transport in soil]

The tested bacterial in this study is the efficient degrading bacteria Chryseobacterium sp. A-3 to methyl tert-butyl ether (MTBE). The bacterial transport parameters during the process of soil bioremediation were described and determined, which included the properties of soils, adsorption isothermal parameters, adsorption dynamics, effective diffusion coefficient and growth coefficients of bacterial. The results showed, compared with other adsorption isotherms, experimental data are correlated reasonably well by Freundlich isotherm models with correlation coefficient of 99.5%. The exponential coefficient is 1.1, which is close to 1. So linear isotherm model can be used to describe the adsorption isothermal process of bacterial in soil. The adsorption constant of Chryseobacterium sp. A-3 value is 0.98 mL/g. The bacteria adsorption dynamics can be well forecasted by the stagnant film theory, which showed the adsorption process is reversible. The microbial reversible attachment rate coefficient is 0. 004 s(-1), and the microbial reversible detachment rate coefficient is 0. 002 s(-1). Based on the membrane cell and fractal dimension model, the diffusion coefficient 3.66 x 10(-6) cm2/s and effective diffusion coefficient 5.18 x 10(-7) cm2/s can be obtained. Simulation of biodegradation process was carried out. The results showed the maximum bacterial growth rate is 0.01 h(-1), the half saturated constant of MTBE is 134 mg/L as well as the biology rate is 0.33. The proposed of determine methods of bacterial transport parameters can be widely used in laboratory and field studies of microbial migration during soil. These parameters are great significance for the model establishment and study of bacteria transport in soil.