DENITRIFICATION WITH BIOGAS AS EXTERNAL CARBON SOURCE

Denitrification with biogas consisting of approximately 60% methane was tested over one year in three types of lab-scale reactors. Denitrification of sanitary landfill leachate with biogas as a sole carbon source was found to be possible. Denitrification rates from 60 mg NO3-N/l * d with an activated sludge reactor, 150 mg NO3-N/l * d with a trickling filter and 550 mg NO3-N/l * d with a fluidized bed reactor were obtained. The oxygen concentration played a significant role in process optimization. Not only high concentrations of oxygen in the liquid medium but also low oxygen concentrations in the aeration gas inhibited denitrification.