하수처리장의 에너지 효율성 개선 방안 연구

Abstract

고유가와 기후변화 협약에 대처하기 위해 우리나라는 2008년, ‘저탄소 녹색성장’을 대한민국의 새로운 국가비전으로 선포하고 “녹색성장 국가전략”을 수립하여 3대 전략 10대 정책방향을 추진 중에 있다. 에너지를 많이 소비하는 환경기초시설 중의 하나인 공공하수처리시설에도 에너지 고갈과 기후변화에 대응하기 위하여 온실가스·에너지 목표관리제가 도입됨에 따라 수처리에 소모되는 에너지 절감 및 신·재생 에너지 이용 등을 통한 하수도시설의 에너지 자립의 필요성이 요구되고 있다. 이에 본 연구에서는 국내 공공 하수처리시설의 에너지 소모 특성 및 에너지 관리 관련제도를 고찰하고 각 공공하수처리시설의 특성을 고려한 에너지 효율성을 평가하여 국내 하수처리시설 에너지 사용량의 근본적인 감소를 꾀하며, 최종적으로 하수처리시설 에너지 자립률을 증가시킬 수 있는 하수처리시설의 에너지 효율적 운영을 위한 에너지 관리 방안을 제시하고자 한다.

In the 60th anniversary of founding the Republic of Korea in 2008, 'Low Carbon, Green Growth' was declared as the new national vision to cope with high oil prices and climate change. The national strategy for "Green Growth" was established with three main strategies and ten policy directions, and the "Framework Act on Low carbon, Green Growth" was enacted in April 2010. Municipal wastewater treatment facilities are considered energy-intensive environmental infrastructures, and they are regulated under the GHG Target management which sets and implements targets for emission reduction, energy conservation, and energy efficiency to respond against energy depletion and climate change. As a result, the importance of energy conservation and recovery in wastewater treatment plants (WWTPs) are being emphasized. In this study, the energy consumption characteristics of WWTP and energy management-related systems were investigated. Also, energy efficiency comparisons among WWTPs were carried out. Finally, measures to improve energy efficiency and energy management at WWTPs are presented. In the last decade, the electricity cost at WWTPs with the capacity of 500 m3/day or more increased by 10.6% per year, and compared to year 2002, the cost increased to 101.9% in year 2009. These increases can be attributed to increases in wastewater that must be treated and advanced treatment technologies equipped to comply with increasingly stringent discharge requirements, among other reasons. In response, the Ministry of Environment has developed the "basic plan for energy independence at wastewater utility" in 2010, which placed a goal to achieve energy self-sufficiency rate of 50% by 2030. The energy efficiency opportunities suggested in the basic plan can be grouped into three broad categories as follows; Replacement of aging equipments with more efficient equipments, and operational improvements Energy recovery, such as biogas, through anaerobic sludge digestion or small hydro power using a discharge of treated wastewater Alternative energy production from photovoltaic power generation, wind power, and others