Activated sludge wastewater treatment plant reduces runtime of aerators from 240 to 180 horsepower
A SolarBee mixer installed at the activated sludge wastewater treatment plant in Eden, N.C., has helped reduced annual electricity cost by 42% and provided an 11-month payback. The unit takes over some of the mixing and oxygenation previously supplied solely by high-horsepower electric aerators.
The main reactor basin where aeration is supplied for mixing required a dozen 20-horsepower (hp) aerators for a total of 240-hp of aeration. This amount of aeration kept total suspended solids in the 3,000 to 4,000 mg/L range, as required by the Environmental Protection Agency’s National Pollution Discharge Elimination System.
“We ran brush aerators constantly to try and mix it all, but they could only mix and aerate the top half,” said plant Superintendent Melinda Ward. “The results were a high, wasteful level of dissolved oxygen at the top of the basin and a mass of sludge at the bottom that wasn’t impacted by the treatment process.”