Cost analysis of activated sludge and membrane bioreactor WWTPs using CapdetWorks simulation program: Case study of Tikrit WWTP (middle Iraq)

Abstract

This paper aims to display benefits of applying economic modeling to predict the most economic treatment among three wastewater treatment plants containing conventional activated sludge without denitrification (CAS), conventional activated sludge with pre-denitrification (CAS-N), and membrane bioreactor (MBR) using CapdetWorks (v.3) simulation software. The software was run for each alternative with an average flow of 30,000 m3/d to calculate and evaluate the current worth costs of these WWTPs. Besides, the price per cubic meter of influent flow of the WWTPs has been evaluated. Tikrit WWTP was selected as a case study. Results demonstrated that the current worth cost of the MBR plant is higher than that for the CAS and CAS-N by about 57%, 42% respectively. Furthermore, the price per cubic meter of influent flow of the CAS plant is 0.2 $/m3. Dissimilarity, costs of the CAS-N and MBR plants are 0.27 $/m3 and 0.43 $/m3 respectively. The low cost of the CAS comes with lower removal efficiencies in comparison to the CAS-N and MBR. Accordingly, the economic modeling is helpful to build and compare relative costs for treatment alternatives which lead to better engineering decisions and suitable selection of the appropriate treatment based on either cost or effluent quality.