RAPID DEGRADATION OF MALACHITE GREEN DYE WASTEWATER USING H2O2 UNDER RECYCLABLE SILICA/MAGNETIC NANOCATALYST

Abstract

The discharge of dye contaminant malachite green (MG) into the water environment will seriously affect human health. In this paper, Fe3O4@SiO2 magnetic nanoparticles were prepared as catalysts using co-precipitation and sol-gel methods, which accelerated the removal of MG by H2O2 over a wide pH range with remarkable results. The degradation mechanism is consistent with the Fe2+-H2O2 Fenton system and the pseudo-first-order kinetic model, and the degradation rate can be increased by 179 times compared with not using this catalyst. When pH ≥ 5, Fe3O4@SiO2 catalyzes H2O2 oxidation of MG for only 10 min to achieve a high degradation rate of 99%, and less than 3 min to achieve a 95% degradation rate. The catalyst can be quickly separated and easily regenerated under an external magnetic field, and a degradation rate of 82% can still be reached after 5 uses. In a word, this work has successfully developed an efficient, green and economic MG wastewater treatment technology.