Access to freshwater is becoming significantly more difficult as the world’s population and the ensuing need for water increase. The extreme demand for this essential need will leave two-thirds of the planet in the struggle of not having enough fresh water. Animal populations are also ravaged by humankind’s reckless use of freshwater. Human carelessness with freshwater shrinks and degrades the habitats of many freshwater animals. Even megafauna such as the Baiji Dolphin are becoming extinct due to habitat loss. Great steps must be taken to support both the planet and its inhabitants. Two-thirds of the earth’s surface is saline ocean water. Saline water is defined as water with a high concentration of salts. The obvious option to prevent the overuse of freshwater resources is to tap into the quintillions of gallons of water right at humanity’s fingertips. But there is an issue with this resource, and it is the first word in the phrase “saline water.” The salinity of ocean water makes the water impossible to use for many of humanity’s needs. This necessitates the desalination of ocean water to use for agricultural and daily needs. The issue with this is that while small-scale desalination such as distillation is available, large-scale desalination remains very expensive. Desalination plants are not very common because they are expensive. Lots of energy must be provided to run these plants. They can filter millions of gallons of water per day, but many people dislike these plants because they create high water costs for nearby residents and cause marine life loss. Most plants use reverse osmosis as the main way to desalinate, but distillation is also a reliable small-scale option.

Distillation is the act of boiling the saline water and condensing the pure water vapor. This leaves the salt and other particles behind. This is a classic method that has been used for millennia. The biggest downside to this is the amount of energy required to heat the water, due to its high heat capacity. This massive energy consumption makes distillation quite impractical for large-scale desalination. Reverse osmosis is another potential way to provide fresh water. It is a reliable yet expensive form of treating saline water. Reverse osmosis is the method of forcing saline water through a semi-permeable membrane which acts like a filter by trapping salt while allowing water to pass through. This is the method used at the Carlsbad Desalination Plant, which is the largest plant in the United States and provides water to over 400,000 people. The Ras Al Khair Plant on the eastern coast of Saudi Arabia is the largest desal plant in the world. It also uses reverse osmosis to cleanse over one million cubic meters of water per day. While expensive for now, the cost for this process will decrease over time, so it should become a more accessible way to treat water. Freshwater is a major necessity to life, but humankind is running out of it. As more of it is used up, new methods of getting usable water must be found. Seawater is a great source of water, but it must be processed to desalinate it. Currently, reverse osmosis remains the most effective way of desalinating water although different methods like distillation exist. As the cost of desalination decreases with improving technologies, humanity can seek to create freshwater from salty ocean water with as few complications as possible.

By: Vishnu Pothera