Biological Denitrification in Attached-growth Reactor

The denitrification in attached-growth system was made using the expanded bed reactor with particle activated carbon as biofilm supporting carrier. The over 95 percent removal efficiency was achieved at a volumetric nitrogen loading of 9 Kg NO\_3_-N/m\^3^-day with the corresponding hydraulic reaction time of only 9.1 min. The average concentration of biofilm in the column was in the range of about 15000 to 20000 mg/l as MLSS equivalence. Therefore, it turned out that the volumetric loadings made possible by use of expanded bed increased to an order of magnitude greater, compared with those in conventional suspended-growth system.departmental bulletin pape