Performance enhancement of SBR applying real-time control

This paper presents the applications of a real-time oxidation reduction potential (ORP) and pH control system to enhance the system performance of a continuous-inflow sequencing batch reactor (SBR). The real-time controlled SBR showed better performances than sequential control regarding substrate removal efficiency and cost reduction. In substrate removal efficiency, good COD, total Kjeldahl nitrogen, and NH₄⁺ removals were achieved by real-time and conventional sequential controlled systems. However, the poor removal of total nitrogen caused by incomplete denitrification in the sequential controlled SBR was improved significantly to 91% by real-time control. Moreover, in contrast with sequential controlled SBR, the real-time controlled SBR can save 14-32% of aeration energy and 11-29% of reactor capacity. Observation of nitrogen compound variations showed nitrites accumulated during the aerobic phase of the real-time controlled SBR. In addition, the kinetics of nitrification and denitrification also proved that the real-time controlled SBR performed the nitrite-type nitrification, which was identified as the key-point of system performance enhancement in the real-time controlled SBR.