Oxidation of refractory organics in attached growth systems: Initial bacterial adsorption

The initial adsorption of a mixed bacterial culture, capable of degrading a phenolic wastestream, on a range of possible support particles was studied in a fluidized bed column. Activated carbon was found to be the most effective support in promoting initial attachment which was well described by a Langmuir type isotherm with values of Cv max and K being 5.48 × 10-3 (g cell DW) (gsupport)-1 and 3.88 (liter) (g cell DW)-1, respectively. Irreversible adsorption occurred very rapidly due either to initial chemical binding or to the immediate synthesis of binding exo-polymers which were observed by SEM at a later state of growth. Actively growing cultures adsorbed more rapidly and more extensively than either those in the stationary or death phase. No temperature effects were observed over the range 18-30°C because of the importance to the initial attachment/detachment of the hydrodynamics and particle collisions