Decoloration of Methyl Orange by Mineral-Catalyzed Fenton-Like System of Natural Schorl and H<sub>2</sub>O<sub>2</sub>

Abstract

The decoloration of methyl orange (MO) dyeing wastewater by mineral-catalyzed Fenton-like system of schorl and H2O2 was conducted in this study. The experimental results showed that schorl could efficiently make MO decolor in the presence of H2O2. Through a number of batch decoloration experiments under various conditions, it was found that the MO decoloration ratios increased by increasing the reaction temperature and the optimum addition of schorl and H2O2 was 1g and 1mL, respectively. At pH=2, a maximum of MO decoloration ratio could reach 99%. About 99.61% of MO decoloration ratio could be achieved in presence of schorl and H2O2, which was much higher than that in presence of schorl or H2O2 only, with MO decoloration ratio of 60.88% and 52.8, respectively, which suggested the schorl-catalyzed Fenton-like reaction governed the MO decoloration process. Otherwise, the MO decoloration ratio could be enhanced under the condition of agitation or UV-irradiation. The decoloration mechanism analysis revealed that the MO decoloration process was governed by a mineral-catalyzed Fenton-like reaction. Fe2+/Fe3+dissolved from the surface of schorl catalyzed the decomposition of H2O2 to produce OH radical, which then oxidized the MO.