REMOVAL OF NITROGEN FROM WASTE WATERS

摘要

In a process of nitrogen removal from wastewater comprising mixing wastewater containing reduced nitrogenous compounds with active nitrifying organisms and an oxygen containing gas and contacting said nitrified wastewater stream with heterotrophic denitrifying bacteria in the presence of a source of organic carbon for a length of time sufficient to reduce the nitrate nitrogen to elemental nitrogen the improvement which comprises heating the biomass removed from the nitrifying and denitrifying steps in the presence of an oxygen-containing gas to partially oxidize the biomass and convert substantially all of the organic nitrogen to ammonia nitrogen, separating the solid phase from the liquid phase of the oxidized mixture, stripping ammonia from the liquid phase and directing said liquid phase to the denitrifying contact step to provide a source of organic carbon.