Estudio de oxidación fotocatalítica de cianuro libre aplicando nanopartículas de manganeso ferrita

Abstract

The mining sector in southern Ecuador, distributed between the Portovelo-Zaruma and Ponce Enríquez Mining Districts, constitutes one of the main economic activities of the Province of El Oro. Mining companies are mostly dedicated to the extraction of gold and silver, where they use large amounts of cyanide, which are usually disposed of in water sources without prior treatment. Cyanide is a highly toxic chemical compound that negatively compromises the health of the population and the well-being of the environment. In response, the present research is based on implementing a photocatalytic oxidation study for cyanide degradation, using a ferromagnetic manganese ferrite catalyst (MnFe2O4). For the preparation of the catalyst, the solutions of ferric chloride hexahydrate and manganese sulfate monohydrate were reacted, taking care that the stoichiometric ratio between iron and manganese is 2:1. Both solutions were mixed and heated to 80 °C with the help of a heating plate. Also, an 8M NaOH solution was heated to the same temperature, the pH of the mixture was adjusted to 10.5 and allowed to react for 1H30 at a constant temperature of 80 °C. Subsequently, the ferrite was washed to remove excess NaOH and dried for 24h at 80 °C in an oven. The characterization of the catalyst was carried out by means of infrared spectroscopy analysis by Fourier transform and X-ray diffraction. The results evidenced that the manganese ferrite nanoparticles obtained have a saturated magnetization of 49.6 emu / g, polydispersity index of 0.30 and a particle size of 245.9 nm.