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

Ziling Peng; Chunmei Xiong; Wei Wang; Fatang Tan; Yang Xu; Xinyun Wang; Xueliang Qiao

doi:10.1016/j.scitotenv.2017.04.121

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

Sci Total Environ. 2017 Oct 15:596-597:266-273. doi: 10.1016/j.scitotenv.2017.04.121. Epub 2017 Apr 21.

Authors

Ziling Peng¹, Chunmei Xiong¹, Wei Wang², Fatang Tan¹, Yang Xu¹, Xinyun Wang³, Xueliang Qiao¹

Affiliations

¹ State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, PR China.
² State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, PR China. Electronic address: weiwang@hust.edu.cn.
³ State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, PR China. Electronic address: wangxy_hust@hust.edu.cn.

PMID: 28437645
DOI: 10.1016/j.scitotenv.2017.04.121

Abstract

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 12h. 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 292.8mg/g within 60min at the initial Cr(VI) concentration of 120mg/L at pH5. 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 as well as the magnetic recovery property, HS-NZVI is expected to have notably promising applications for the remediation of Cr(VI) contaminated sites.

Keywords: Cr(VI) remediation; Modification; Nanoscale zero-valent iron; Stability.