FLUIDIZED-BED REACTOR OPERATION FOR GROUNDWATER DENITRIFICATION

Groundwater denitrification was carried out in a laboratory scale flui dized bed reactor using sand particles as the biomass carrier. This pa per is concentrated on the fluidized bed reactor operation at very hig h nitrate loading rates (between 30 to 100 kg.NO3/m(3) reactor/day) wi th corresponding short retention times (5 to 1.5 minutes). The effects of nitrate loading rate on nitrate and nitrite removal, as well as on reactor biomass profiles and biofilm characteristics, are presented i n this article. The results of the present study indicate that this ty pe of reactor can operate efficiently at retention times shorter than 3 minutes and at nitrate loading rates higher than 70 kg.NO3/m(3)/day. However, this system requires careful control of the biofilm thicknes s to achieve a reliable reactor operation.