Abstract:
Abstract: In recent years, heterogeneous Fenton oxidation technology based on nano Zero-Valent Iron (nZVI) has become a hot topic in the field of antibiotic wastewater research. However, the disadvantages of nZVI's easy migration and agglomeration limit its further application. In order to solve this problem, iron-carbon nanoloaded zero-valent iron materials were prepared using ethylenediamine tetraacetic acid (EDTA) and melamine (MA) as ligands and ferrous acetate as iron source by a combination of mechanical ball milling and pyrolysis, and characterized by Sulphaphenazole (STZ) as the target contaminant. The influencing factors and mechanism of sulfathiazole degradation by iron carbon materials were investigated. Characterization results show that the acetic acid ferrous@ethylenediamine tetraacetic acid (Fe@EDTA) of the nano particle diameter of about 4 nm, the uniform distribution in the carbon layer, this structure makes material has stronger catalytic ability, and the nZVI in ferrous acetate@melamine (Fe@MA) aggregates into large particles with a diameter of about 400 nm and is coated with a carbon layer of 100 nm. The best Fe/C ratio of Fe@EDTA material is 2:1, the best Fe/C ratio of the material is 3:1, the best experimental conditions are the initial pH is 3, the initial H2O2 concentration is 15 mM or 25 mM, the catalyst dosage is 0.1 g/L or 0.2 g/L, the pollutant concentration is 10 mg/L or 20 mg/L; The degradation of sulfathiazole and the production of hydroxyl radical were in accordance with the pseudo-first-order kinetic model. Fe@EDTA material has good reusability and stability. After five repeated experiments, the degradation rate of pollutants is still up to 82%. The reusability and stability of Fe@MA materials are relatively general, and the degradation rates of pollutants in the fourth and fifth repeated experiments are about 52% and 48%. The mechanism of degradation of STZ was discussed. The mechanism of heterogeneous Fenton system between iron carbon materials and hydrogen peroxide (Fe@C-H2O2) was fenton-like oxidation induced by nanometer zero-valent iron, in which hydroxyl radical (∙OH) and superoxide radical (∙O2-) played a key role in the oxidative degradation of organic pollutants.