DEVELOPMENT OF BIOFILMS IN ANAEROBIC REACTORS

The development of biofilms in polyethylene sheets and particles was studied using downflow reactors with synthetic nutrient media made up of a mixture of volatile fatty acids. Results suggest a preferential immobilization of acetoclastic organisms in the inner space of the surfaces and the colonization by the butyrotrophic bacteria in the outer layers. After 101 days the bioparticles reached a specific acetoclastic activity of 72.45-mu-mol acetic acid/mu-g protein .h while the biofilms had 58.80-mu-mol acetic acid/mu-g protein attached .h. Due to the low density of the polyethylene particles low fluidization velocities would be needed (2m/h) in a downflow fluidized bed reactor.