Nanotech Water - Membranes: The Pulse of the Planet daily radio program offers free legal online mp3 downloads, exploring the world of sound in nature, culture and science, with audio adventures, world music, extraordinary sound portraits, science diaries, and nature ring-tones; an amazing sonic experience.

Airdate: Feb 17, 2016
Scientist: Kimberly Jones

Nanotech Water - Membranes

Nanotech Water - Membranes
Wastewater plants typically don't filter out pharmaceuticals from our water supply.

Nano - Membranes

Ambience: Water trickling through membrane in lab
Many of the drugs we take pass through our bodies and end up in our wastewater treatment facilities. But wastewater plants typically don't filter out pharmaceuticals from our water supply. I'm Jim Metzner and this is the Pulse of the Planet.

Jones : Now that we know that pharmaceuticals exist in streams and rivers and lakes and other bodies of water, we're busy in our labs trying to understand what treatment processes can remove the pharmaceuticals. In our lab, for example, we work with membranes. Membranes tend to be very, very efficient at removing these contaminants, because membranes can remove things that are very small in size.

Kimberly Jones is a professor and the chair of the Department of civil and environmental engineering at Howard University.

Jones : Membranes are really a separator or barrier for contaminants. So most membranes that we design, will let water go through the membrane, and they will not let contaminants go through. So it's a way of separating harmful material from water. So it's the same principle of a coffee filter. Only if you can imagine the pores can get really really small, which means they can reject smaller and smaller contaminants. But they also need a much higher pressure to force the water through these smaller an smaller pores.
One thing were doing in our lab to improve membrane materials, is were using nano materials. For example, one of our projects we incorporated silver nano materials into the surface of the membrane.

Silver nanoparticles as small as one billionth of a meter, have the useful property of being able to kill bacteria.

Jones : By incorporating silver and eliminating bacterial growth on the membrane, it makes us able to use the membranes for a lot longer before we have to clean them, and it reduces the cost of membrane treatment.

Pulse of the Planet is made possible in part by the Center for Earth and Environmental Nanotechnology and the National Science Foundation. You can hear this and past programs on our podcast.