Riding the Waves to Clean Water

By PSU EcoMerge Capstone - 10:25 PM

Potable water is a relatively scarce resource world-wide despite the Earth's surface consisting of about 71% water. The problem is that the vast majority of the Earth's water comes from the ocean and is not safe for humans to drink due to its high salt content. And much of the fresh water on the Earth's surface is locked away in glaciers and icecaps, leaving us with even less fresh water than is actually accessible.

Fresh water can still be found naturally in rivers, lakes and underground, but these forms of fresh water are not always available to certain regions of the world. This often applies to those who live in a desert climate where fresh water is exceptionally scarce. Qatar and Israel are examples of countries that have a much more severe water scarcity problem compared to other areas of the world. However, these countries are still able to meet all of their water requirements with the use of modern technology. They are able to turn sea water into potable drinking water by using a process called desalination.

Desalination uses reverse osmosis to separate salt and other impurities from sea water by passing the sea water through a semi-permeable membrane. The sea water must be highly pressurized to achieve this separation, but the result of the process provides clean drinking water than can be distributed as tap water to the local population. This may sound like a great way to solve humanity's water scarcity problem but this process is not without its drawbacks.

Desalination is normally a very expensive process. The reason countries like Israel and Qatar are able to use this as a solution for providing fresh water is because they are very wealthy countries. The process also requires a tremendous amount of energy to pressurize the water to the level needed to achieve desalination. This usually involves a power plant burning fossil fuel to satisfy the high energy requirement, contributing to a high amount of pollution. There is also a problem with dumping the leftover brine back into the ocean. The higher concentration of salt in the brine can have a harmful effect on ocean life. But not using this technology is really not an option for parts of the world that have limited fresh water.

Like many technologies, efforts are being made to make desalination cheaper and more environment friendly. SAROS (Swell Actuated Reverse Osmosis System) is a company that has developed prototype devices that use the energy of ocean waves to power the desalination process. They are able to turn sea water into fresh, drinkable water by using a buoy to pump sea water to the necessary pressure for reverse osmosis to work. It is much cheaper and environmentally friendly than conventional desalination plants. Although, the SAROS method is done on a much smaller scale in comparison. The question is whether the method can eventually match the scale of traditional desalination plants. According to a representative from SAROS, there may be a practical limitation on its scalability.

In the mean time, SAROS will be working to assist in providing fresh water to remote communities that struggle with water scarcity. They plan to work with non-profits and other organizations to bring their technology to those who need it the most. It would make sense for them to partner with Green Empowerment since the two organizations seem to have similar goals.






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