The influence of different electrolytes on sulfentrazone dechlorination by iron-nickel bimetallic nanoparticles

Abstract

Kinetic studies of sulfentrazone herbicide dechlorination by Fe/Ni nanoparticles were performed in the presence of different electrolytes such as: Cl-, SO42-, NO3-, Cu2+, Na+ and Zn2+. In the presence of Cl- and SO 4 2- the reaction occurred effciently, reaching approximately 100% of dechlorination after 30 minutes of reaction. In the presence of NO3- and Cu2+ ions the sulfentrazone dechlorination was signifcantly inhibited, because these ions tend to compete with the substrate for the electrons donated by Fe0. In the presence of Na+ ions, the dechlorination effciency remained approximately 100%, however, this electrolyte provided an increase on the reaction rate, due to the increase of the ionic strength in the system. The Zn2+ ions has no influence on the dechlorination effciency, but the reaction rate was reduced due to the formation of a protective layer formed by the sorption of Zn2+ ions on the surface of the nanoparticles.