Ferrous disulfide and iron nitride sites on hydrochar to enhance synergistic adsorption and reduction of hexavalent chromium

Yuxin Liu; Tianye Wang; Ningning Song; Quanying Wang; Ying Zeng; Shaoqing Zhang; Hongwen Yu

doi:10.1016/j.biortech.2023.129770

Ferrous disulfide and iron nitride sites on hydrochar to enhance synergistic adsorption and reduction of hexavalent chromium

Bioresour Technol. 2023 Nov:388:129770. doi: 10.1016/j.biortech.2023.129770. Epub 2023 Sep 14.

Authors

Yuxin Liu¹, Tianye Wang², Ningning Song², Quanying Wang², Ying Zeng², Shaoqing Zhang², Hongwen Yu³

Affiliations

¹ Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
³ Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address: yuhw@iga.ac.cn.

PMID: 37714497
DOI: 10.1016/j.biortech.2023.129770

Abstract

In this study, a novel hydrochar containing ferrous disulfide (FeS₂) and iron nitride (FeN) was prepared via a one-pot hydrothermal method to enhance the synergistic adsorption and reduction of hexavalent chromium (Cr(VI)). This material (Fe3-SNHC) exhibited a Cr(VI) removal capacity of 431.3 mg·g^-1 and high tolerance to coexisting anions at pH 2. Adsorption occurred via monolayer chemisorption. Variation in material structure and density functional theory calculations proved that multiple active sites formed by interactions between heteroatoms improved the chemical inertness of hydrochar. FeN and FeS₂ with two electron-donating groups had strong reducing ability to facilitate the conversion of Cr(VI) to trivalent chromium. It was concluded that next to electrostatic adsorption and complexation, synergistic reduction among multiple active sites were the dominant mechanisms involved in the removal Cr(VI). This study shows that Fe3-SNHC is a promising and environment-friendly material for Cr(VI) to remove it from wastewater.

Keywords: Biowaste; Heavy metal; Hydrothermal conversion; Iron nitride site; Multi-heteroatom co-doping.

MeSH terms

Adsorption
Chromium / chemistry
Water Pollutants, Chemical* / analysis

Substances

chromium hexavalent ion
pyrite
iron nitride
Water Pollutants, Chemical
Chromium