Comparative Life Cycle Assessment of Four Municipal Water Disinfection Methods

The disinfection of treated water is an important process to provide healthy water to the public. The chosen disinfection methods can vary depending on the water source, regulations, targeted microorganisms, operating conditions, capital costs and operation and maintenance costs. Another important factor for decision-makers is the environmental impacts caused by the disinfection process. This paper will reveal the life cycle assessment (LCA) of four different water disinfection scenarios at a municipal scale from the operational phase. A comparison is made between chlorination systems, two ultraviolet disinfection systems that use different types of lamps and an ozonation system. The results demonstrate that the UV disinfection system with low-pressure lamps had the lowest environmental impact across all categories, followed by chlorination. In contrast, the ozonation system and the UV disinfection system with LED lamps showed the highest impacts in all categories, primarily due to their high electricity consumption. Changes in the electricity mix had a substantial influence on the impact categories for all disinfection methods, but the gradation of the water disinfection methods was not that significant. Studies on the environmental impacts of the water disinfection process need to be carried out for larger flow rates to increase the information on this topic.