Water, an essential element for life, make up 71% of the planet's surface. Paradoxically, only 3.5% of this water is suitable for human consumption, to be found in lakes, rivers and springs to supply our physical and hygienic needs. The remaining 96.5%, located in seas and oceans, is not drinkable due to its high level of salinity.
How to harness this inexhaustible source of life? The technology of water desalination makes it possible. Man has devised many systems to convert sea water into drinking water and be able to provide the population with difficulties with access to fresh water.
Methods like electrodialysis, reverse electrodialysis, multistage flash distillation or multi-effect distillation work in desalination plants operating worldwide. However, the most widespread and most advanced system is the water desalination by reverse osmosis, whose implementation involves 61% compared to other systems.
In this infographic we show you how the process of reverse osmosis desalination works, since salt water is caught in the sea until drinking water is obtained for use and consumption:
Does the brine that is returned to the sea have some negative impact?
It is a common question but it should be noted that there is no negative impact on the environment. The brine is returned to the sea under strict environmental conditions and potential problems are minimized. Harmful salt concentrations are avoided through outfalls or diluting the brine with seawater in tanks before returning to sea.
The desalination plant in Jávea (Alicante, Spain) is a good example of management discharge of brine: it was the first reverse osmosis desalination plant in the world that dilutes the rejected brine to minimize environmental impact (Watch video).
How many people use desalinated water?
Nowadays, up to a hundred and fifty countries host desalination plants of some sort. Overall, these plants supply with desalinated water to approximately 300 million people.
As for the global implementation of this technology, there are more than 17,000 desalination plants in the world producing 66.5 million cubic meters of desalinated water daily, although the installed capacity worldwide would be able to desalinate more than 80 million cubic meters per day.