Preparation of zero-valent iron@Fe3O4 and its removal performance study for trichloroethylene

Abstract

Trichloroethylene (TCE) is a common organic pollutant with low solubility in water, leading to its accumulation within the soil layer and posing risks to groundwater system. In this study, the zero valent iron@Fe3O4 (nZVI@Fe3O4) with diameters in the range of 500 nm to 1500 nm and thickness between 2 and 3 nm were successfully synthesized by ascorbic acid mediated reduction of FeCl2 in an N2-filled glove box, and proposed to boost the degradation of TCE. Research findings indicate that a starting TCE concentration of 20 mg/L can achieve a removal rate exceeding 80 % after 60 min, with an impressive adsorption capacity of 32.09 mg/g. The acidic environment plays a crucial role in enhancing the elimination of TCE by nZVI. Additionally, it was observed that a high NaCl concentration negatively impacts the effectiveness of nZVI in TCE removal, with the most significant inhibition observed at a NaCl concentration of 1000 mg/L. The adsorption of TCE by nZVI was consistent with the Langmuir model for monolayer adsorption, and the removal process was consistent with the quasi-secondary kinetic model. Importantly, the nanomaterials prepared in this experiment using disproportionation reaction have good economic and environmental benefits.