Simultaneous Nitrification and Denitrification for Treating Slightly Polluted Water with Heterotrophic Nitrification Bacteria and Aerobic Denitrifiers

Three strains of heterotrophic nitrification bacteria and three strains of heterotrophic nitrification bacteria are isolated from sediments of a reservoir respectively,and immobilized in suspended sponge spherical pellets,which is used as media in an experimental biological contact oxidation system for treating slightly polluted water. The experimental result indicates that after an operation of 17 days,removal of NH4+-N could attain 100% and TN 42% under the condition of water temperature of 25℃,DO 4mg/L and a long hydraulic retention time.