December 20, 2013

Jet-propelled wastewater treatment

Swimming microengines made from platinum and iron are highly efficient in removing organic pollutants from water using hydrogen peroxide.

Researchers from the Max Planck Institute for Intelligent Systems in Stuttgart have developed a new method for the active degradation of organic pollutants in solution by using swimming microengines. The mobile microcleaners consist of an outer iron and an inner platinum layer, thereby combining two functionalities. Hydrogen peroxide, which must be added to the contaminated solution, acts as fuel for the platinum micromotors and as reagent for degrading organic pollutants on the iron layer. Not many methods for the successful cleaning of polluted wastewaters exist. The Fenton reaction, one of the most popular advanced oxidation processes for the degradation of organic pollutants, relies on spontaneous acidic corrosion of the iron micromotor surface in the presence of hydrogen peroxide. The scientists report that the oxidation of organic pollutants achieved by a swarm of these self-propelled microjets is twelve times higher than when using immobile iron microtubes.