The Grand Portage Reservation is at the northeastern tip of Minnesota. The Air Quality Program has many ongoing projects in order to maintain healthy indoor and outdoor air. These projects include monitoring for regional haze and particulate matter, indoor air quality, invasive plant removal, public outreach, environmental education, alternative energy, and climate change.

Wednesday, March 13, 2013

New Nanoscale Filter Can Desalinate Water 100 Times More Efficiently

Although this is not directly air related, this could be a game-changer for regions suffering for lack of fresh water. Climate change is already worsening droughts worldwide, and this trend is only going to increase as global temperatures rise. A new type of filter developed by Lockheed Martin uses sheets of a carbon material called graphene with nano scale holes which allow water to pass through easily but trap salt molecules. Compared to current filters it takes 100 times less energy to push the water through the filter, and if this technology can scale up it could be shaped into filters that could retrofit current desalination plants.
From the report:
The process, officials and engineers at Lockheed Martin Corp say, would enable filter manufacturers to produce thin carbon membranes with regular holes about a nanometer in size that are large enough to allow water to pass through but small enough to block the molecules of salt in seawater. A nanometer is a billionth of a meter.
Because the sheets of pure carbon known as graphene are so thin - just one atom in thickness - it takes much less energy to push the seawater through the filter with the force required to separate the salt from the water, they said.
The development could spare underdeveloped countries from having to build exotic, expensive pumping stations needed in plants that use a desalination process called reverse osmosis.
"It's 500 times thinner than the best filter on the market today and a thousand times stronger," said John Stetson, the engineer who has been working on the idea. "The energy that's required and the pressure that's required to filter salt is approximately 100 times less."

Desalination plants are huge consumers of electricity and with demand for fresh water constantly rising this method could help reduce electric consumption worldwide. Desert regions with ocean access could use solar powered desalination plants which could allow for irrigation in places where it once was prohibitively expensive. As I said, not directly air related but a development that could have huge implications for energy use in the future and that does affect air quality.

1 comment:

Warner Carter said...

Obviously this is a pretty serious design flaw that i've reported to Brita. I've also bought multiple versions of this same pitcher to diagnose whether or not the first one was a lemon. Unfortunately they're all the same. Pur water filters