This research investigated the effect of COD/N ratio on nitrogen removal, and the use of organics in raw wastewater as a carbon source for denitrification in SBR (Sequencing Batch Reactor) systems.
Four laboratory scale reactors were operated in three modes. Only the difference between modes were; Mode I operated in aerated condition during fill wile Mode II in anoxic condition. Mode III operated on two fills per cycle in anoxic condition.
When COD/N ratio increased, total nitrogen removal efficiencies increased from 8.7 to 57.7 percent in Mode I, from 28.9 to 83.2 percent in Mode II and from 42.7 to 97.8 percent in Mode III, respectively. COD removal efficiencies ranged from 93 to 98 percent through the study. When SBR is operated in Mode III, nitrogen concentrations in effluent can be estimated based on influent COD and nitrogen concentrations. Anoxic operation during fill and feeding twice per cycle were found an effective operating method for nitrogen removal in SBR system.
