Using numerical simulation software for improving wastewater treatment

The aim of this paper is to show the using of numerical software in order to improve the wastewater treatment plants efficiency from the design phase. The use of computer simulation programs to evaluate and design wastewater treatment plants is becoming more prevalent; design engineers often implement models without adequate influent characterization and calibration. In this paper the STOAT (Sewage Treatment Operation and Analysis over Time) software is considered to simulate a real wastewater treatment plant, to analyze the solids retention time and the nutrients (N and P compounds) in the effluent taking into account different activated sludge models.