Using a Dynamic Process Model to Investigate Full-Scale Upgrades to Maximize Secondary Wet Weather Treatment Using Step-Feed

摘要

The Metropolitan Sewer District of Greater Cincinnati (MSDGC) is implementing plans tosignificantly reduce combined sewer overflows (CSO) through secondary treatment plantupgrades. Major upgrades at the Mill Creek Wastewater Treatment Plant (WWTP) includemodifications of the existing secondary clarifiers to improve sludge removal and hydraulics, andconversion of the 3-pass activated sludge lanes to be able to operate in step-feed operation. Thispaper discusses operational modeling investigations using state point analysis and biologicalprocess modeling with Biowin to develop guidelines for operating the step feed mode.Furthermore, full scale plant performance of step-feed operation and process model predictionsunder wet weather conditions are presented and show that the field data matches the modelpredictions reasonably well. The model demonstrated that it is a powerful tool that can be used topredict plant performance and guide plant operations.