MIT scientists develop new technique for cleaning contaminated water

NEW YORK - A group of researchers at Massachusetts Institute of Technology (MIT) is on a mission to take charge of waste water purification.

The team, lead by Dr Xiao Su, use an electrochemical method, where positively and negatively charged electrodes are placed inside polluted water.

The electrodes' surfaces are coated with special polymers, tuned to strongly bind with specific impurities, in this case a compound containing a pharmaceutical pollutant.

Su says the highly selective process can even capture micro-pollutants, things that can exist in small, but potentially dangerous amounts in water.

He says their method is highly effective.

"The concentration went down dramatically, so probably around 95 to even 98 per cent of this pollutant actually got removed. And the water's actually quite clear. If you leave it for longer, you can actually get to very, very low amounts and then probably, possibly the drinking water quality," said Su.

The researchers say their process is superior to others as it operates on low voltages wasting less energy, while creating almost no byproducts.

They hope their technology can be scaled up for larger bodies of water containing different types of waste.

"What we'd like to do is have a technology where we can flip the switch - the light goes on, and we can do the separation. We flip the switch off, the light goes off, and we are able to regenerate our systems," said MIT Chemical Engineering Professor Alan Hatton.

The team is working with agricultural partners in the US to clear waste streams of fertilisers and pesticides, and in the future hopes to power though industrial waters to clear it from harmful contaminants.