HERNDON, Virginia — Around 790 million people worldwide don’t have access to an improved water supply or a water supply that is protected from outside contamination. Unsafe water causes disease, diarrhea-related mortality and even death. Lack of access to clean water is closely intertwined with poverty and the causal connection goes both ways. The “average American uses 100 to 175 gallons of water per day” and the largest source of water usage is the toilet.
Toilet flushing can use more than one-fourth of one household’s water. Many toilets worldwide utilize freshwater, which consequently places an even larger strain on the globe’s very limited resources since only about 3% of the water on earth is freshwater. Of this 3%, less than 1% is accessible for human use. In realizing this urgent issue, researchers at the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have been searching for ways to alleviate the freshwater supply burden. KAUST research has been looking for and found new solutions to the problem.
KAUST Research on Wastewater
Pascal Saikaly, an associate professor at KAUST, leads a team of researchers that focuses on a salt-tolerant bacterium culture found in the Red Sea, Candidatus Scalindua sp. AMXII, which can remove salt from wastewater. Therefore, researchers say that the bacteria could potentially replace more freshwater toilets with toilets that utilize seawater. This bacteria’s main role is to remove nitrogen from seawater so that it becomes safer for both the environment and for human usage. In Saikaly’s research group, they used real seawater to test the effectiveness of Candidatus Scalindua sp. AMXII and found that it could treat around 90% of wastewater and successfully remove a high level of nitrogen from seawater.
The next step for this research team is looking for other necessary bacteria to accompany Candidatus Scalindua sp. AMXII. This way, its findings could be applied to larger-scale treatment. The team hopes to eventually implement the research into actual treatment centers in coastal cities as cities along the coast are more likely to use these kinds of toilets for preserving freshwater and use less energy for desalination processes. In addition to research on a larger scale, KAUST researchers have also partnered with a Saudi fertilizer company to test the bacteria’s efficiency on industrial wastewater. With hopes of expansion and more elaborate findings, the team expects its research will benefit many communities worldwide.
Hong Kong Preserving Freshwater
Various parts of the world already use seawater toilets, including Hong Kong, Singapore and Tokyo. Hong Kong implemented a separate water distribution system in the 1950s and currently treats the wastewater with chlorine. Though some argue that using chlorine may be harmful, researchers have found that Hong Kong’s system saves freshwater while also contributing to wildlife conservation in coastal areas.
The seawater quality complies with the Water Supplies Department’s (Government of Hong Kong Special Administrative Region) regulations and guidelines to ensure safety. By using seawater for toilet flushing, Hong Kong has been able to reduce freshwater consumption by 20% every year. The system has been in use for more than 50 years.
Conclusively, as more than 50% of the world lives along the coast, the KAUST research results could potentially cause a drastic reduction in the world’s freshwater use as proved by Hong Kong’s system. If wide use of the Candidatus Scalindua sp. AMXII bacteria becomes feasible for larger-scale use, then it will have an impact on problems tied to freshwater access, such as poverty, too. Therefore, it would mean one step closer to better serving the underserved.
– Grace Wang