How Does Desalination By Reverse Osmosis Work?

Around the world, countries suffer from shortages of fresh water. At the same time, many of these lands have an abundance of seawater just beyond their long coastlines. Removing the salt from this water could produce plenty of fresh water and remediate these shortages. In fact, plenty of people have wondered if California could benefit from desalination through a process called reverse osmosis. Learn more about how this process works and if it’s a workable solution in the United States and overseas.

How Does Reverse Osmosis Desalination Work?

Even though the term sounds complex, it’s fairly easy to explain the process of reverse osmosis Basically, the saltwater solution gets forced through a membrane that filters out the salt to produce desalinated water. The membrane’s holes are large enough to allow water molecules to pass through, but they’re too small to allow salt molecules to flow with them. With reverse osmosis, one side collects fresh water, and the other one keeps a more highly concentrated brine solution.

Water plants use a special filter made from cellular acetate. Scientists first developed this material for photographic applications and only later discovered that it made a great filter for salt water. A plant in Coalinga, California has relied upon this material and method to desalinate water since the 1960s, and it’s now employed in over 100 countries around the globe. This kind of technology has been tested very well.

Drawbacks of Reverse Osmosis Desalination

If the process of turning into sea water works so well, why doesn’t everybody do it to deal with shortages of fresh water? After all, seas cover two-thirds of the planet. Actually, critics say that this kind of desalination comes with some problems that doesn’t make it an ideal solution for every situation.

The high cost of developing one of these desalination plants creates a big obstacle. Many developing countries simply lack the finances to complete a project. Also, the typical yield of fresh water may only be 15 percent of the total, so these nations have to build very large plants to yield enough drinking and irrigation water to justify the effort.

Concerns over the environmental impact of water desalination present another obstacle. Once the process creates fresh water, the leftover waste consists of a very salty brine that might damage delicate ecosystems by harming the wildlife and plants in the area.

Overcoming Obstacles To Desalination

Developing countries don’t always have to finance an entire project by themselves. Some global organizations that try to help with financing include UNICEF and The World Health Organization.

Even better, scientists have made recent advances that help increase yields and even deal with the high concentration of salt in the waste. They reduce waste by diluting the brine back into regular saltwater or wastewater that eventually comes back through the system. These new systems even use water pressure to make the system work, so that helps to defray energy costs.

What is The Future Of Water Desalination Via Reverse Osmosis?

Reverse osmosis technology has proven itself workable over decades. As technology improves, these systems may hold the key to producing plenty of fresh water for drinking, irrigation, and other uses.