Diffusion of microbe plays an important role in microbial restoration of soil and groundwater.For saturated soil,a membrane cell was designed to measure the effective diffusion coefficient.In this study,the theory of fractal dimension was also used to calculate the cell constant of bacteria and the tortuosity factor of soil membrane.In the experiment of KCl diffusion,cell constant of KCl was directly calculated.In the second experiment the model of fractal dimension was used and the cell constant of microbe diffusion was obtained.Using the model of fractal dimension,tortuosity factor was also deduced.The effective diffusion coefficient of bacteria was obtained.
