Nano-material filters could cut cost of cleaning water
By Wong Mun Wai, Channel NewsAsia | Posted: 04 June 2007 1703 hrs

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SINGAPORE: The cost of filtering and recycling water could be reduced in a few years' time due to a new material developed by Nanyang Technological University (NTU) and the Public Utilities Board (PUB).

This was revealed at an international water conference here, called the International Water Association Conference and Exhibition on Water and Wastewater Technologies.

The material that is being engineered by researchers from NTU and the PUB uses nanotechnology, which controls matter on a scale smaller than 1 micrometre, and is made up of nano-sized crystals.

And because the crystals are so tiny, they are able to capture a large amount of unwanted matter in the water.

That is why the nano-material works better than conventional cleaning filters or membranes.

Associate Professor Darren Sun, School of Civil and Environmental Engineering, NTU, said: "Conventional polymer membrane is just a filter. But this new technology will make the filter double up as a reactor which will be able to destroy unwanted material."

The nano-material destroys unwanted matter like dissolved salts and chemical compounds in water by using ultraviolet light and visible light.

The material then clears its surface to allow more unwanted material to collect.

The final goal, which will take a few years, is to make a cleaning filter or membrane out of the nano-material.

The focus now is on testing the material and possibly removing one stage of the pre-treatment of waste and sea water.

Researchers said another objective of the new filter is to prolong the lifespan of the membrane and reduce costs.

For now, the results of tests conducted are promising.

To date, the filter can remove at least 20 percent more organic carbon which is one of the parameters to assess cleaner water.

The PUB estimates that a pilot plant could be built to test the nano-material at Chua Chu Kang Waterworks in about two years and the research project may apply to a scheme called Fast-Tech to fast-track water projects.

Also announced at the conference is the S$300,000 Lee Kuan Yew Water Prize, which recognises organisations or individuals who come up with solutions to water problems.

Nominations will open from the end of June.

The winner will be announced next March and presented in June at the first Singapore International Water Week.


- CNA/so