Determining Economic Feasibility: A Cost Analysis of an Adsorption Based Wastewater Treatment Plant

Abstract This paper presents a three way cost comparison between three different methods of wastewater treatment: a conventional activated sludge plant, an adsorption based plant and a surcharge based system. We assumed plant capacity of 1 million gallons per day and wastewater composition of 2% phenolic compound, BOD5 of 1370 mg/L and TSS of 1400 mg/L. Capital, construction, non-construction, operational and maintenance costs for all three systems were calculated, and their costs discounted over a period of ten years to find the Net Present Value in first quarter 2016 USD. The discount rate used was 8% as that was the average weighted average cost of capital for wastewater treatment firms across the United States. NPV was determined to be positive $31,000,000 for an adsorption based plant assuming 100% efficiencies, negative $14,600,000 for a conventional activated sludge plant, and negative $9,100,000 for a surcharge system. There is potential for significant revenue generation in the resource recovery stage of an adsorption process, where up to $6,200,000 worth of steam can be generated when the adsorbent is burned off. Therefore, this study shows that an adsorption based wastewater treatment plant can be economically and financially feasible.