Development of simplified biofilm sorption and diffusion experiment method using Bacillus sp. isolated from Horonobe Underground Research Laboratory

摘要

We developed a simplified biofilm sorption and diffusion experiment method. The biofilms of the Bacillus cereus were incubated on cellulose acetate membrane filters (pore size 0.2 μm, diameter 47 mm) placed on thick NB broth agar medium (thickness was about 30 mm) to support sufficient biofilm growth of the Bacillus cereus. The thickness of the formed biofilms was about 1 mm. The formed biofilms were applied to through-diffusion method, which has been used to measure diffusion coefficient of crystalline and sedimentary rocks and clay minerals. The obtained copper sorption coefficient by batch experiments was about 100 ml/g (wet weight) at the case of the concentration of cupper ion was over 0.074mmol/L. And diffusion coefficients by through diffusion experiment was De=1.1 × 10~(-10) (m~2/s). From these results, this simplified biofilm sorption and diffusion experiment may make possible to obtain these parameters with ease.