Currently, an estimated 728 million people worldwide do not have access to water deemed ‘clean’ by the United Nations. This results in around six to eight million deaths each year from water borne disease (1). It is no secret that over the coming years clean water will likely become one of the world’s most valuable resources.
To solve this issue, science is looking towards utilizing the world’s oceans, earth’s largest reservoir of water. This seems quite the obvious choice as salt water from the ocean accounts for nearly 97% of all water on earth; while, on the other hand, accessible fresh water occupies less than 1%. However, the process of turning seawater into water that can be used by humans is expensive and inefficient with current technology.
Thankfully, due to its vast potential, several companies and organizations are working on improved desalination methods. One of the most intriguing and promising new methods comes out of the Massachusetts Institute of Technology. Researchers there have developed a new means to desalinate water through a process referred to as ‘shock electrodialysis’.
The process starts when water flows through a frit, a porous material made of small glass particles, with electrodes and a membrane lining the sides. An electric current is then sent through the entire system; as a result, the salt water divides into areas where the concentration is either high or low. Next, “When that current is increased to a certain point, it generates a shockwave between these two zones, sharply dividing the streams and allowing the fresh and salty regions to be separated by a simple physical barrier at the center of the flow (2).” Though this process may seem complex at first glance, it is actually rather straightforward and will be relatively easy to implement.
The most important aspect of this new technology is the efficiency and cost at which it will run. Current methods of desalination, such as reverse osmosis, require expensive filters that are prone to clogging after some time. With shock electrodialysis, the water is not run through a filter, but through cheap porous material made of small glass particles. Additionally, the material and infrastructure required for this process is much simpler than with traditional desalination. This means that large scale use of this method could be done with relatively low operating costs; good news for impoverished countries in need of clean water.
Another benefit lies in the diversity of this process. Shock electrodialysis also excels in purifying potentially dangerous contaminants from water, not just salt. This means that not only could this method treat seawater, but it could also clean toxic ions in groundwater that has been contaminated. This would be useful for the wastewater generated by fracking; a popular method of natural gas extraction in the United States.
At this time, this technology is in its infant stages as researchers have yet to move the experiment past a relatively small scale. However, in the future, shock electrodialysis could help provide millions with clean, affordable, potable water.
(1) Facts and figures. (n.d.). Retrieved June 14, 2016, from http://www.unwater.org/water-cooperation-2013/water-cooperation/facts-and-figures/en/
(2) Chandler, D. L. (n.d.). Shocking new way to get the salt out. Retrieved June 14, 2016, from http://news.mit.edu/2015/shockwave-process-desalination-water-1112
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