published on 14 April 2016 in water
Micro-robots for wastewater treatment
They are thinner than a human hair, swim like fish and, most importantly, are able to eliminate heavy metals from wastewater. What exactly are we talking about? About micro-robots, designed to purify industrial wastewater, often rich in heavy metals, such as mercury, lead and cadmium, the major causes of environmental damage and poisoning of living organisms. The technology has been developed by an international team of researchers, who recently published a paper in the scientific journal Nano Letters. These autonomous and reusable micro-robots are really efficient and are, in fact, able to remove 95% of the lead present in contaminated water within one hour.
The secret of such efficiency lies in their three constituent layers: an outer graphene oxide layer, which absorbs the lead particles present in the water; a central nickel layer, which allows the robot to be controlled via a magnetic field, and, finally, an inner platinum layer, which gives the robot self-propulsion by adding to water hydrogen peroxide with which the platinum interacts. The magnetic field that controls them, moreover, can be used to recover them and, once cleaned of the lead particles, they are ready to return to purifying the water.