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.

本文旨在展示应用经济模型预测三个废水处理厂中最经济的处理方法的好处，这些废水处理厂包含常规的不脱氮活性污泥（CAS），预脱硝的常规活性污泥（CAS-N）和膜生物反应器（MBR）使用CapdetWorks（v.3）模拟软件。该软件针对每种替代方案运行，平均流量为30,000 m ³/ d来计算和评估这些污水处理厂的当期成本。此外，还对污水处理厂每立方米进水的价格进行了评估。提克里特污水处理厂被选为案例研究。结果表明，MBR工厂的当前价值成本分别比CAS和CAS-N高出约57％，42％。此外，CAS工厂每立方米进水的价格为0.2 $ / m ³。相差不大，CAS-N和MBR工厂的成本分别为0.27 $ / m ³和0.43 $ / m ³分别。与CAS-N和MBR相比，CAS的低成本具有较低的去除效率。因此，经济模型有利于构建和比较治疗方案而导致更好的工程决策和基于成本或出水水质适当的治疗的合适的选择相对成本。