Just right

Abstract

The automated control system provides enough oxygen to meet the system needs by handling constant variation. Prevoiusly controlled aeration system wasted energy and promoted unstable biological conditions for its oxidation ditch. The automated control system includes a programmable logic controller (PLC), variable-speed drives, and a continuous, on-line dissolved oxygen (DO). The DO monitor is installed in the innermost channel and the variable speed drives on the two aeration motors. The continuous DO monitor consist of a float ball with a DO sensor mounted near the bottom. The sensor remains underwater and the smooth surface prevents debris from grabbing on and affecting DO readings. The automated control system aerators uses less power and the power consumption follows flow pattern. The total power consumption of the plant dropped an average of 6%, even though influent flows had increased by an average of nearly 20%.