IMPROVING PLANT PERFORMANCE AND ENERGY EFFICIENCY IN A SEQUENCING BATCH REACTOR AND EXTENDED AERATION FACILITY IN CENTRAL OKLAHOMA USING ADVANCED RESPIROMETRIC MONITORING

In August of 2003 Severn Trent Services began a survey of two wastewater treatment facilities in Central Oklahoma using the Mobile Analytical Trailer (MAT2000) technology which is based on assessing the biomass using a respirometer. This respirometer technology measures the oxygen uptake rate (OUR) to determine the loading of the facility, the biomass health, and the appropriate detention time needed to reach the state of endogenous respiration where all readily biodegradable wastes are treated. The respirometer is a key in allowing simulations of plant process to be performed in a quick and efficient manner in order to consider process changes.The first facility surveyed was in Mustang, Oklahoma which is a 1.5 MGD sequencing batch reactor where the staff was experiencing treatment problems in one of the reactors. This particular reactor was producing poor settling and higher ammonia concentrations. After the loading of the reactor was determined over a few days it was quite apparent that the aeration time needed exceeded that of the setting of the aeration cycle time in the SBR. The cycle time was adjusted by extending the aeration setting for an additional hour of aeration and lowering the time for the settling cycle. Within a few days the effluent quality significantly improved in terms of settling and ammonia concentration in the settled supernatant.In late February of 2004 the MAT2000 was then moved to the Chickasha, Oklahoma which is a 3.0 MGD extended aeration facility where there were questions to the possibilities of reducing the aeration capacity to save electrical costs. In the initial analysis it became quite apparent that the facility had potential for reduction in aeration capacity as the respirometeric data showed endogenous respiration rates throughout the aeration basins. Approximately half of the aeration basin was taken offline in late May and is currently being monitored to ensure that the capacity is adequate for treatment. Initial results have been positive to indicate that the reduction in capacity is a feasible option. The electrical costs associated with this have potential to be quite significant with the reduction in aeration needs and sludge processing.