Evaluation of capital and operating costs of the domestic and urban wastewater treatment plants according to different treatment processes in our country

Wastewater treatment plants which have been increasing in number in recent years, require an important financing requirement for the Municipalities, especially considering the CAPEX and OPEXs. Designing WWTP projects one of the high-investment environmental infrastructure projects, with the right process is very important for minimizing the CAPEX and OPEXs. In addition to selecting right processes, the initial investment and operating costs of different biological treatment processes in different population and flow ranges must be estimated accurately at the feasibility stage. In this thesis study, the initial investment costs of 230 WWTPs from different processes built across the country were compiled from the tender documents and data obtained from the facilities. The initial investment costs of 129 WWTP constructed between 2011-2018 which consists of 71 simultaneous nitrification/denitrification Bio-P processes, 16 5-stage Bardenpho processes, 26 extended aeration activated sludge processes (EAAS), 9 oxidation ditches, and 7 conventional activated sludge processes, were investigated. Based on these data, equations and graphs have been created showing the relationship between facility capacity and initial investment cost and population and initial investment cost. The initial investment costs in WWTPs are between 37 euro and 90 euro per person for 129 WWTPs consisting of 5 different treatment processes and the average cost for these WWTPs is calculated as 64 euro per person. Operating costs in WWTP's were evaluated by TURAAT project data, survey results conducted by SUEN in 2019 and data obtained from some water and sewerage administrations, and WWTP operation cost and electricity consumption are calculated as 0.036 Euro/m3, 0.27 kWh/m3 for extended aeration activated sludge process and as 0.057 euro/m3, 0.40 kWh/m3 for 5-stage Bardenpho processes, respectively.