Improving Effluent Total Nitrogen Using Advanced Dynamic Control of Aerobic/Anoxic Phasing

The BIO-DENIPHO® process accomplishes both nitrification and denitrification within a pair of tanks though a repeating cycle alternating anoxic and oxic phases without separate anoxic reactors or internal recycle streams. Typically, the phase lengths are manual fixed inputs into the control system. As Process conditions are not constant, Fixed Phase Control cannot provide optimal process performance. Therefore, a Dynamic Phase Control strategy has been developed were phases are automatically adjusted as process conditions vary.This paper presents results from the study of the Dynamic Phase Control strategy at the North Cary WRF, NC. The study showed that process can be significantly optimized by incorporation of Dynamic Phase Control. It showed a 40% reduction in TN and reduced aerator runtime (10-12%). Full-scal experience at the BioDenipho WWTP in Highspire, PA indicates that the Dynamic Phase Control can achieve 10-15% reduction in aeration energy and reduce TN concentrations by 2-3 mg/L.