Original Research - Seawater Desalination

The lack of sufficient sources of fresh water may not seem like a crisis in New Jersey, but many parts of the world face this monumental issue. Approximately 1 in 6 people lack access to safe water, water that is necessary for cooking, farming, drinking. A way to combat the steadily growing deficiency of fresh water as the world’s population steadily increases is through a process known as desalination. To desalinate water is just as the word implies---to remove the salts from briny water. This conversion from saltwater/seawater to fresh water is accomplished through a couple of techniques and has eye-opening advantages over other solutions to the water crisis, but also has some outstanding shortcomings that need to be fixed.

            To begin, one technique to desalination is distillation. To distill salt water, large amounts are heated to evaporate pure water from the liquid. The large structure containing the process then separates the once saline water into two products: fresh, almost pure, water and very briny water. Another way to desalinate water, the most popular, is through membranes and filtration. Two processes under this category are reverse osmosis and electrodialysis. Basically, a semi-permeable membrane removes ions, the salts, selectively, after a filter has removed most of the impurities.

            Several advantages of desalination are that the supply of water from the ocean is unlimited, the water product is relatively pure, and it removes the need to destroy or infringe on other sources of freshwater. However, there are negative aspects to the workings of the many desalination plants throughout the world. Although the cost of desalination has decreased over past years, this method of purification is still expensive in comparison to others. Also, tons of energy is consumed in the process; it isn’t “green.” Additionally, it negatively impacts marine life and the environment. Larger animals are killed on the impact screen through impingement; small organisms are killed in the process through entrainment. The briny solution left over contains nitrates, iodine, lead, and lots of salt, and there is no useful or safe place for it to be disposed.

            Ultimately, while desalination has some major distinct advantages over other methods of obtaining safe water, problems are evident that need to be fixed: the cost, the excessive energy consumption, the death of marine organisms, and the harmful briny leftover.