In ancient times, the world provided living things with sufficient amount of potable water through freshwater ponds, lakes, and streams among others. Unfortunately, the rapid surge of population growth and environmental damage greatly reduced such availability of drinkable water, thereby pushing man to find ways on how to maximize other water sources.
According to the United Nations, around 1.8 billion individuals are predicted to live in areas with scarce water supplies by 2025. Increasing industrial demand, droughts, and population growth are primary contributors of water shortages in the world.
It was late President John Kennedy who once proposed to obtain freshwater from saline water, but at the most economical way possible. The breakthrough happened in 1960 when researchers of the University of California Los Angeles (UCLA) discovered the first membrane material now used in desalination plants.
Such membrane is used in the process known as reverse osmosis (RO), which is basically the opposite of natural osmosis. Osmosis is the process that keeps your body from dehydration as it achieves a state of equilibrium between high and low concentrated solutions. The contrary happens in RO systems.
Rather than achieving equilibrium, only the concentrated water is forced through the other side to leave behind large particles (i.e. salt molecules). The highly concentrated solution (e.g. saltwater, brackish water) is completely diluted and converted into fresh, drinking water.
This process is suitable in coastal areas or locales near oceans such as California, which currently has more than 20 small desalination plants across the state.