Abstract
The performance and economic simulation and modeling are crucial for accurate and rapid designing, construction, and forecasting future economic needs of municipal wastewater treatment plants (MWWTPs). In this study, combined nitrifying trickling filter/activated sludge (NTF/AS) process was suggested for the modernization of a MWWTP and the performance and economics of MWWTPs based on the combined TF/AS process and combined NTF/AS process were analyzed and compared. In real, the performance, total project construction, total operation labor, total maintenance labor, total material, total chemical, total energy, and total amortization costs of these proposed MWWTPs were calculated and compared. Under the used design criteria and operational conditions in this study, the project construction cost of the MWWTP based on TF/AS was 15.25 % higher than that of the MWWTP based on NTF/AS. Also, MWWTP based on NTF/AS was cost effective and the material and amortization costs for both plants were higher in comparison with the operation, maintenance, energy, and chemical costs. It is necessary to note that this study is a computer simulation for a case and drawing general conclusions only on the basis of this simulation may be insufficient.