NITRATE REDUCTION IN ACIDOGENIC REACTOR - INFLUENCE OF WASTE-WATER COD N-NO3 RATIO ON DENITRIFICATION AND ACIDOGENIC ACTIVITY/

The denitrification and acidogenic potentials of a laboratory scale co ntinuous stirred anaerobic reactor have been investigated. The reactor was fed with synthetic wastewater containing nitrate and glucose as c arbon source. Under fixed conditions of chemical oxygen demand (COD) a nd hydraulic retention time (HRT), and under varied input nitrate conc entration, volatile fatty add (VFA) production without denitrification occurred at COD/N-NO3 ratios > 220; denitrification and VFA productio n at 88.5 less than or equal to COD/N-NO3 ratios less than or equal to 220 and denitrification and smallest VFA rates at COD/N-NO3 ratios < 44.3. At COD/N-NO3 ratios > 130, nitrate assimilation appeared to be t he main nitrate reduction pathway. Lowest concentrations of VFA in out let are obtained at COD/N-NO3 ratios < 20.