Investigation of Energy Efficiency in Wastewater Treatment Plants

In this study, energy efficiency of five full-scale municipal wastewater treatment plants with a population equivalent (p.e.) ranging between 33300-343000 were investigated. all of the plants are based on activated sludge process conducting biological nutrient removal. a systematic for calculation of energy consumption based on plant operation data and power consumption of the installed equipment was developed. specific energy consumptions of treatment plants were compared with each other. based on population equivalent and wastewater flow, specific energy consumption of the plants changed between 28.6-54.3 kwh/(p.e.).year and 0.24-0.42 kwh/m3, respectively. it was also calculated that 19-37% of the total energy consumption in these plants can be potentially recovered by anaerobic digestion of waste activated sludge generated in the plants. therefore, a reduction in the energy and sludge disposal costs can be achieved.