EFFECT OF SOLIDS RETENTION TIME ON NITROGEN REMOVAL IN INTERMITTENT CYCLE EXTENDED AERATION ACTIVATED SLUDGE (ICEAS) SYSTEM
The effect of food to microorganism ratio (F:M) on nitrogen removal in intermittent cycle extended aeration activated sludge (ICEAS) system, has been studied using a large pilot scale treatment system. A basic operation schedule for BOD removal was used in the study. The objective of the study was also to develop data that would provide additional insight regarding the mechanisms for enhanced nutrient removal. Simultaneous nitrification and denitrification takes place during the aeration phase, and nearly complete denitrification takes place in the settling sludge blanket during the sedimentation and decant phases. The study has demonstrated that the ICEAS system can provide enhanced nitrogen removal at different F:M ratios by adjusting the SRT. Nearly complete nitrification takes place in the reactor operating at an SRT of 20 days, with a total inorganic nitrogen removal of 70 %