Today’s Solutions: December 19, 2025

Freshwater is a scarce and valuable natural resource. Humans couldn’t survive without it, so why do we waste precious freshwater to flush our toilets? Researchers from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) are trying to solve this water-wasting dilemma with the creation of a saltwater toilet, and they’re using a new variety of bacteria to help them do so.

Traditional sewage treatment systems use two types of bacteria to treat sewer water and remove nitrogen before it is recycled into our waterways, but one of these varieties: anaerobic ammonium oxidation bacteria, only works in freshwater.

To get around this roadblock, the researchers cultivated bacteria from the Red Sea called Candidatus Scalindua sp. AMX11. This new type is 90 percent effective at removing nitrogen from a nitrogen-rich seawater solution. The team’s research was published in the Water Research journal, but the next step towards developing a saltwater toilet is testing the treatment method in a larger scale sewer system. 

On a planet where water is a precious resource, converting our toilets to use salt water is a great solution for large scale water conservation with a minimal impact on people’s daily lives.

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