Pollutant-Fighting Particles Purify Water
January 15, 2010
Two Carleton Univ. professors are getting $159,000 to purify drinking water and sewage in ways no one has before.
Current technology filters out the major dirt and kills the germs, but doesn’t do much to remove tiny bits of toxic waste that come from drugs, pesticides and cosmetics.
Edward Lai of the chemistry department and Banu Ormeci, an engineer, are using invisibly small particles that stick to pollutants and remove them from water.
On Tuesday, Carleton announced the two will receive funding from the Canadian Water Network, a federally-funded center of excellence that supports research into cleaner water.
“In simple terms, these are tiny little ‘smart’ particles that can bind to these emerging compounds (pollutants) in water and remove them,” Ormeci explains.
Ormeci’s and Lai’s work could apply to drinking water plants, urban sewage treatment, or treatment of wastewater from a factory.
They can engineer little particles to seek out and bind to one pollutant - for instance, a particular chemical in waste from a factory that makes one or two specific drugs. Or they can design a general type of particle that will bind to a wider variety of chemicals found in sewage, or in a river that supplies drinking water.
The next step is to remove the tiny particles and their toxic burden, “and there are potentially several methods to do that.”
The materials they use to build the particles are polymers - common, cheap chemicals related to plastics.
“And that’s the point. In developing technologies that can be applied at full-scale treatment plants, you want the technology to be effective, but … cost-effective as well,” Ormeci says. “Polymer particles, especially at the large scale, are very inexpensive.”
The two researchers are targeting chemicals that cause health effects at very low levels. Some disrupt the hormone systems of humans and wildlife, posing threats to fetal development and young children. Sources include birth control pills, over-the-counter drugs, antibiotics, cosmetics and fragrances. (People take the drugs and excrete them in urine.)
They’ve worked for two years so far, and are ready to scale up from cupfuls of water to industrial-scale pilot projects. The new grant will fund two more years.
“We want to increase the removal efficiency of the particles (and) test them on different compounds such as pharmaceuticals and personal care products.”
Ottawa’s east-side sewage plant will also be involved in the future work. Ormeci has a Canada Research Chair in Wastewater and Public Health Engineering.
Source: Carleton Univ.
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