Fitter Filter

obmar · Site Admin Joined: 14 Apr 2006 Posts: 5697

Conventional water and air filters work in a number of ways - by acting like a sieve to catch particles larger than a certain size and by relying on electrostatic forces to trap particles, for example. Ideally, they can also filter water under the force of gravity and at high throughput rates. But few, if any, achieve all these goals.

Now Fred Tepper at Florida water filtration company Argonide Corporation says he has a filter that achieves all this and more. Funded by the US Air Force, Tepper and his colleague Leonid Kaledin have produced a filter made of aluminium oxide fibres embedded in a larger tangle of cellulose fibres. The celluose matrix (pictured) traps larger particles while holding the aluminium oxide nanofibres in place, preventing them from being washed away or forming into clumps that would block the filter. The nanofibres trap smaller particles using electrostatic forces and conventional sieving. Tepper says the nanofibres can even be coated with biological molecules designed to latch onto the specific pathogens used in biological weapons. And to top it all, the filter can produce a decent volume of water working only under the force of gravity.

Read the next generation filter patent application

Justin Mullins, New Scientist contributor