SINGAPORE - Water used to wash clothes could be recycled with the help of a special type of clay.
National water agency PUB will fund a $42,500 trial to test whether bentonite clay can be used to remove soap-based pollutants from used water.
If the trial is successful, the eventual goal is to create a system that can be installed at industrial laundromats to help Singapore re-use more water.
Researchers also hope to come up with a smaller cartridge that families can add to their washing machines. About one-fifth of a household's water consumption is for doing laundry.
The nine-month trial will start in April and is a collaboration between PUB and Ngee Ann Polytechnic's Environmental and Water Technology Centre of Innovation.
It aims to build on the findings of a previous award-winning project by Anderson Junior College (AJC). Last year, a team of AJC students developed a method to use bentonite clay to clean soapy water without creating waste by-products. It removed 99 per cent of non-ionic surfactants, soap-like additives used in industrial and household detergents, from the dirty water.
The used bentonite clay could also be flushed clean with alcohol and used again, the students said, but other researchers said this would require a lot of alcohol and could be expensive.
Current methods to treat laundry waste water usually produce hazardous sludge.
The project won the annual Singapore Junior Water Prize - organised by Ngee Ann Polytechnic and the Lien Foundation and supported by PUB - last May, and clinched the international Stockholm Junior Water Prize in August. It was the first time Singapore won the prestigious annual competition since it began taking part in 2008.
Ms Ang Pei Ling, 31, a research and development engineer at the polytechnic's water technology centre, said her team plans to refine the students' tests in the new trial. For example, the AJC students added chemicals to water to simulate laundry waste water. PUB will provide Ngee Ann Polytechnic with actual industrial waste water.
A new area the polytechnic wants to explore is whether used bentonite clay can be deployed to remove pollutants from other industries' waste water. Previous studies suggest soaking up the soap-like additives could modify the clay and make it more effective in removing other chemicals from used water, said Ms Ang. "For example, we want to test the modified clay on toluene, a toxic chemical commonly used as a solvent," she added.
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