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Seawater Desalination

For thousands of years, scholars have tried to solve water shortages by trying to figure out how to make ocean water potable. In ancient civilizations, a god or goddess controlled water, and they were used to differentiate between seawater and clean water found in the lakes and streams. If the water Gods became angry, the water dried up and forced migration which caused hardships and loss.

seawater1

            In ancient times, Europeans would pray to Melusine who was believed to be the goddess of freshwater. Cursed by her water-fairy mother for seeking revenge against her commoner father, King Elyneos, she became a mermaid-like figure who became the caretaker of springs and lakes.

In 350 BC, Aristotle found a way to distill water after he theorized in Meteorologica that vaporized saltwater became sweet, and the salt did not reform once the water condensed. In the 2nd-century BC, the Egyptians began to practice distillation. In the 17th-century, the Japanese practiced distillation using bamboo stilts and earthen pottery. Historically, it was cheaper and more gainful to distill wine rather than water.

In 1881, the first commercial desalination plant opened in Tigne, Sliema, Malta. By the early 20th-century, scientists were still using Aristotle’s definition to describe the technology for a thermal distillation approach to desalination, but the way to do it had advanced considerably.

Types of seawater used for desalination processing:

  • Deep Seawater
  • Shallow Surface Seawater
  • Beach Well Seawater
  • Brackish River Water

Desalination Methods:

  • Distillation:
  • Multi-stage Flash distillation, Vapor Compression. Multi-effect distillation
  • Ion Exchange
  • Membrane Process
  • Electrodialysis reversal, Reverse Osmosis, Nanofiltration, Membrane Distillation, and Forward Osmosis.
  • Freezing Desalination
  • Geothermal Desalination
  • Solar Desalination
  • Solar humidification, Multiple-effect humidification
  • Methane Hydrate
  • Water Recycling
  • Seawater Greenhouses

 

In the mid-twentieth-century, polymer science became the primary technique used for water purification. However, over the last decade, desalination has become much more scientific in nature because of membrane separation that has proven to be an affordable option for clean water.

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            Water plants have become a critical element for water production globally. The expenses for building and maintaining them have deterred some countries from even beginning desalination processing programs. Only 18,426 plants exist worldwide. They produce more than 22.9 billion gallons of drinkable water per day for more than 300 million people who rely on processing stations in 150 countries. Even so, almost half of the world is without a means to receive clean water which means more must be done to get the ocean’s resources to those who need it most.

Socio-economic concerns significantly hinder this process globally. The UN released information, in 2014, showing that 1.2 billion people live in areas where water shortage is a genuine threat because many societies have no choice but to rely on rainwater collection or the ability to recycle wastewater. Another 1.6 billion live in areas that lack the infrastructure to pump clean water from nearby water sources.

Some countries have continued to rely on the belief that natural resources will be abundantly available in the future. Other factors like environmental laws and production costs prevent water production initiatives. However, some private organizations like the Global Programme Water Divison have taken the lead in overcoming political and socio-economic conditions to solve the water crisis by finding solutions to drinking, agricultural, and cross-border management of water resources.

The ocean offers an unlimited supply of water for saltwater desalination processing. With a global effort, seawater and renewable energy could quickly become the viable solution to this problem. Socio-economic conditions could also change in that access to clean water could become a global right instead of a commodity afforded only to those who have the resources to buy it.

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