국내 공공하수도 시설의 에너지 사용 및 자원화실태 조사연구

Abstract

To establish effective and prompt measures for energy conservation in public wastewater treatmentplants in Korea, energy consumption rates in 233 utilities in 9 provinces and 7 metropolitan cities areinvestigated and compared to the rest of the world. Mean load factor for wastewater treatment utilities is74.9% and those for influent pumps and aeration blowers are 56.2% and 61.0%, respectively. Meanelectrical energy usages as the key performance indicators are 0.243kWh/m3 for overall sewagetreatments and 2.07 kWh per unit kg BOD removal. Digester gas as one of major byproducts in the processamounts to 382,000m3/day nationwide. While major part of the digester gas is used for sludge heating,only 7.3% of the gas is utilized for electricity generation. Both efficiencies for BOD removal and digestiongas generation are considerably lower than those in USA and EU utilities due to low concentration oforganic material in influent wastewater. Such low energy regeneration, in turn, results in significantly higherenergy consumption in Korean plants, compared to that in USA and EU ones.