Life Cycle Assessment In Energy Costs And Environmental Benefits Of Wastewater Treatment Project

With the accelerating process of urbanization, urban water supply problems is becoming seriously gradually. Admittedly, the construction and operation of water treatment plants project could relieve the situation of urban water pollution effectively and improve the quality of urban water environmental quality. However, the water treatment plants would also cause a certain negative impact on the environment during its life cycle periods. Life Cycle Assessment could comprehensively analyze the natural resource and energy consumption, and environmental impact of water treatment plants from its whole life cycle periods, including construction, operation and destruction. Besides these, Life Cycle Assessment could provide a considerable suggestion for proposed relative project based on its qualitative and quantitative analysis.This paper introduces the concept, the evaluation framework model and the methods of Life Cycle Assessment. And then establish a Life Cycle Assessment framework and system for sewage treatment project based on urban wastewater treatment situation. The instance in this paper is Cyclic Activated Sludge Technology (CAST) in Xi'an third sewage treatment plants, its inventory of natural resource and energy consumption, and waste emission during whole life cycle periods is comprehensively collated and analyzed. Here we can calculate the energy costs, while analyze and evaluated the positive and negative benefits of environmental impact of wastewater treatment plants in this instance. Its main conclusions are as follows:1. The whole energy consumption of Xi'an third sewage treatment plants is 3579.89 x109kJ during its life cycle period. The energy consumption in its operation phase is 3213.04 x109kJ, which accounted for 90%of total.2. The EB value of Xi'an third sewage treatment plants during its life cycle period is energy consumption caused global warming and atmospheric acidification, which is 2612.03 and 248.91.3. In the part of evaluation improvement, the paper proposes energy cost reduction measures based on blower room and pump room operation as sewage treatment process reorganization, layout improvement, air flow control and so on.