Saltwater Sanitation

Freshwater makes up less than 1% of all of the Earth’s water. With the world’s population set to hit ten billion by the year 2050, scientists are searching for ways to conserve this essential and rare resource.

One area that has been greatly overlooked is sanitation. Nearly a third of all freshwater is flushed down the toilet. Using seawater could alleviate pressure on freshwater resources. Boats use this method while at sea, and it’s already in use in cities such as Honk Kong, Singapore, and Tokyo.

With so much of the Earth’s population living near coastlines, it is a viable idea, but applying this solution on a larger scale comes with a drawback: traditional water treatment processes use nitrogen-removing bacteria, that can’t survive the high salt content of seawater.

Researchers from Saudi Arabia’s ‘King Abdullah University of Science and Technology’ set out to solve this dilemma by developing a salt water toilet. Their search for answers led them to the Red Sea, which has a higher salt content than any other body of water in the world.

After three years of testing, they discovered a bacterium, called Candidatus Scalindua, species AMX11. This single cell micro-organism can remove 90 percent of nitrogen from salty wastewater and therefore, can be used to treat the saltwater sewage.

This discovery could change the way populated coastlines treat their wastewater, conserving billions of gallons of freshwater in the process.

The next step towards developing a saltwater toilet is testing the treatment method in a larger scale sewer system. The team is also working with a Saudi fertilizer company to test this bio-process for treating industrial wastewater, another area of great need.

On a planet where water is such a precious resource, flushing it, is absolutely foolish. Saltwater toilets are just the beginning, in saving drinkable water for future generations.