Comparative life cycle assessment of end-of-life options for reverse osmosis membranes

With continuing growth in the reverse osmosis water treatment industry and the finite lifespan of the membranes, the number of membrane modules requiring disposal is expected to drastically increase over time. This study aimed to provide a quantitative assessment of the environmental impact from membrane manufacturing and its impact on the desalination process, using the tool of life cycle assessment. The results showed no significant difference between the manufacturing of 16″ and 8″ elements, and that module fabrication contributed to less than 1% of the CO2-e emissions for the production of potable water from seawater. The study also looked at the environmental impact of a number of proposed end-of-life disposal options for membranes within the context of the Australian desalination industry. The results of the study show that membrane reuse over one year is more environmentally favourable to landfill disposal, regardless of the transportation distance required. However, in terms of direct reduction of waste to landfill, incineration provided the greatest benefit, at the expense of increased greenhouse gas emissions. Overall, this study provides detailed quantitative information for membrane users and manufacturers to enhance their decision making process when it comes to end-of-life membrane options.