Facile modification of nanoscale zero-valent iron with high stability for Cr(VI) remediation

作者：Peng, Ziling; Xiong, Chunmei; Wang, Wei^*; Tan, Fatang; Xu, Yang; Wang, Xinyun^*; Qiao, Xueliang

来源：Science of the Total Environment, 2017, 596: 266-273.

DOI：10.1016/j.scitotenv.2017.04.121

• Nanoscale zero-valent iron
• Modification
• Stability
• Cr(VI) remediation

In this study, a highly stable nanoscale zero-valent iron composite (HS-NZVI) was obtained via modifying nanoscale zero-valent iron (NZVI) with tetraethyl orthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMOS), and used for Cr(VI) remediation in aqueous solution. The obtained HS-NZVI remained stable in water without being oxidized for over 12 h. After four consecutive runs, the Cr(VI) removal efficiency of HS-NZVI maintained a value of more than 82%. Moreover, the Cr(VI) removal capacity per unit weight of NZVI in HS-NZVI reached 292.8 mg/g within 60 min at the initial Cr(VI) concentration of 120 mg/L at pH 5. The Cr(VI) removal efficiency of HS-NZVI increased with decreasing solution pH, and the experimental data for Cr(VI) removal by HS-NZVI were well-described by the pseudo-first-order reaction model. Additionally, scanning electron microscope (SEM) images, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) measurements of the product after reaction revealed that the mechanism of Cr(VI) remediation by HS-NZVI mainly involved adsorption, reduction and co-precipitation. Considering the advantages of easy preparation, excellent stability and reusability, and high Cr(VI) removal capacity aswell as the magnetic recovery property, HS-NZVI is expected to have notably promising applications for the remediation of Cr(VI) contaminated sites.

• 出版日期2017-10-15
• 单位华中科技大学