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The Honolulu Advertiser
Posted on: Monday, March 13, 2006

HAWAI'I'S ENVIRONMENT
Filter gets metals out of water

By Jan TenBruggencate
Advertiser Columnist

University of Hawai'i researchers led by Liangjie Dong, a doctoral candidate in molecular biosciences and bioengineering, have developed a new, inexpensive filtration system that removes not only bacteria but also heavy metals from water.

The system would be only slightly more expensive than activated carbon filtration, and "carbon can't remove heavy metals," Dong said.

The new technology is being called MicroNose, since it functions somewhat like the mucous membrane of the human nose, he said.

Dong's development team includes Walt Atkins, of Pacific HiTech Development, and University of Hawai'i-Manoa researchers James Cowen, an oceanographer; geophysicist Li-Chung Ming; economist P.S. Leung; materials scientist Pavel Zinin; water quality engineer Chittaranjan Ray; and social scientist Kate Zhou.

"We also have some international collaborators," Dong said.

They anticipate the technology will have special application in Third World countries where drinking water may be compromised. The filtration system will remove arsenic, lead, cadmium and other heavy metals.

In testing, it reduced arsenic levels by 99.9 percent, Dong said.

And while foreign applications may be the most critical, the system could also help U.S. communities meet strict EPA water quality requirements, he said.

A test with groundwater contaminated with arsenic at a rate of 300 parts per billion showed that the MicroNose system cut that to 1 part per billion after a 15-minute filtration process.

In a press release, Dong said he experimented with dozens of compounds before developing the final product, granules made of clay, iron and other materials. The granules function mechanically — they contain microscopic holes that allow small water molecules to pass, but block the big molecules of bacteria and heavy metals.

"The MicroNose formula is very precise, but can be easily mass produced," he said. He said it could be used in any application in which activated carbon filters are used, including large-scale industrial applications, home faucet filters and even hand-held filters that campers could carry.

The University of Hawai'i Office of Technology Transfer and Economic Development has applied for a patent on MicroNose.

Dong said the research group has a working model of its system, and is now looking for financing to develop commercial applications for MicroNose.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.