Life Cycle Assessment of a Municipal Wastewater Treatment Plant

• Main Authors: Huan-Yu Shiu, 許桓瑜
• Other Authors: 闕蓓德
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/38531838936438211661

碩士 === 國立臺灣大學 === 環境工程學研究所 === 102 === 　　Waste water treatment plants are an important foundation for urban water management. While there has been greater emphasis on the efficiency, convenience in operation, maintenance, and overall environmental impacts, energy and chemical input, as well as waste emission also cause significant environmental effects. 　　Life cycle assessment is used to evaluate the environmental benefits and impacts associated with the treatment of a wastewater treatment plant in Kinmen, Taiwan. The objective of this study is to compare the current treatment process with several other proposed advanced treatment processes. The system boundary of the present LCA includes operation and maintenance phase, sludge treatment and disposal, and water reuse. 　　In this study, life cycle assessment software SimaPro 7.1 and CML 2 baseline 2000 methodology were applied to evaluate functional units of 1 m3 treated water. The results show that energy has the most significant impact on environment, with a total impact of 79%. Recycled water used in agriculture, on the other hand, has the most significant benefits. While tertiary treatment systems will increase environmental impact by 55%, using recycled water in the city also increases environmental benefits by 50%. Similarly, in the sludge treatment system, power consumption is the most significant factor responsible for environmental impacts. Sludge used in agriculture can reduce methane, nitrous oxide and sulfur oxide formation, thereby increasing environmental benefits by 54%. Impact of sludge generated by incineration, as well as energy recycling, can reduce overall environmental impact by 86%. Sludge as a building material is the highest among impact scenarios. Finally, to further reduce the environmental impact arising from sewage treatment plants, energy is chosen as the first priority.