Development and Calibration of a BioWin Process Model to Evaluate Treatment Alternatives for Optimized Efficiency

A biological process model was developed using BioWin to evaluate treatment performances at the Truckee Meadows Water Reclamation Facility (TMWRF) in Reno, Nevada. Historical flow and loading data for the facility were analyzed and used to develop a preliminary BioWin model for the existing plant layout. To aid in model development, several different two-week sampling campaigns were implemented to capture the plant influent loading and target chemical constituent concentrations in internal recycle streams. The sampling campaigns helped determine the influent wastewater fractions needed to properly calibrate the BioWin model. Upon further investigation, process data revealed that the activate sludge Systems 1 and 2 within the facility operate differently; as such, the two systems were modeled and calibrated individually. By sampling both the plant influent and recycle streams separately, and modeling each process flow as their own input, the model can be readily modified if influent loads or internal processes change in the future. The BioWin model for the existing process scheme was developed so that alternative processes can be investigated. Research efforts then focused on expanding the model to evaluate anticipated performance of alternative treatment configurations. The alternatives investigated include activated sludge reconfiguration for biological nutrient removal (BNR) treatment and chemical treatment for enhanced phosphorus removal. BNR activated sludge configurations investigated include the anaerobic/anoxic/aerobic (A2O), 5-stage Bardenpho, Standard and Modified University of Capetown (UCT), Virginia Initiative Plant (VIP), and Modified Ludzack-Ettinger (MLE) processes. In combination with the MLE activated sludge configuration, chemical treatment for enhanced phosphorus removal was also investigated. After analyzing carbon and nutrient removal between the alternative treatment configurations, the aeration demand was investigated to compare requirements of the current process to proposed alternatives. Finally, the energy and chemical costs of the current TMWRF process were compared to the alternative designs