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^-, SO₄^2-, NO₃^-, Cu²⁺, Na⁺ and Zn²⁺. In the presence of Cl^- and SO₄^2- the reaction occurred efficiently, reaching approximately 100% of dechlorination after 30 minutes of reaction. In the presence of NO₃^- and Cu²⁺ ions the sulfentrazone dechlorination was significantly inhibited, because these ions tend to compete with the substrate for the electrons donated by Fe⁰. In the presence of Na+ ions, the dechlorination efficiency 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 efficiency, 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.

Key words:
Bimetallic nanoparticles; Electrolytes; Fe/Ni; Dechlorination; Sulfentrazone