A new study by researchers at Yale University, United States, argues that seawater desalination should play an important role in helping address worldwide fresh water shortages once conservation, reuse and other methods have been exhausted. One-third of the world’s population already struggles to keep up with the demand for fresh water, and that number is expected to double by 2025. The study also explores ways in which desalination technology can be made more affordable and energy efficient. According to Menachem Elimelech, a professor of chemical and environmental engineering at Yale and lead author of the study, “The globe’s oceans are a virtually inexhaustible source of water, but the process of removing its salt is expensive and energy intensive,” adding that the leading method for seawater desalination today – reverse osmosis – requires a minimum amount of energy that cannot be overcome. The researchers suggest that the real gains in efficiency can be made during the pre- and post-treatment stages of desalination, suggesting that membranes that do not build up organic matter on their surfaces could help avoid any pre-treatment of seawater. Additionally, a membrane that was capable of filtering out boron and chloride would result in substantial energy and cost savings. While Elimelech cautions that desalination should be a last resort in the effort to provide fresh water to the world’s populations, he believes desalination has a major role to play now and in the future. “All of this will require new materials and new chemistry, but we believe this is where we should focus our efforts going forward,” Elimelech said. “The problem of water shortage is only going to get worse, and we need to be ready to meet the challenge with improved, sustainable technology.” The study was published in the journal Science.
http://opac.yale.edu/news/article.aspx?id=8775