Characteristics and long-term effects of stabilized nanoscale ferrous sulfide immobilized hexavalent chromium in soil

Xin Li; Xiao He; Hang Wang; Yangsheng Liu

doi:10.1016/j.jhazmat.2020.122089

Characteristics and long-term effects of stabilized nanoscale ferrous sulfide immobilized hexavalent chromium in soil

J Hazard Mater. 2020 May 5:389:122089. doi: 10.1016/j.jhazmat.2020.122089. Epub 2020 Jan 15.

Authors

Xin Li¹, Xiao He¹, Hang Wang¹, Yangsheng Liu²

Affiliations

¹ College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing 100871, China.
² College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing 100871, China; School of Urban Planning and Design, Peking University Shenzhen Graduates School, Shenzhen 518055, China. Electronic address: yshliu@pku.edu.cn.

PMID: 31978819
DOI: 10.1016/j.jhazmat.2020.122089

Abstract

Based on the phenomenon of soil polluted by Hexavalent chromium (Cr(VI)), this study systematically examined the efficiency, stability and feasibility of using sodium carboxymethyl cellulose-stabilized nanoscale ferrous sulfide (CMC-nFeS) to immobilize Cr(VI) in contaminated soil. The experiments described herein showed CMC-nFeS exhibited superior dispersity and a higher antioxidative effect than nFeS alone. Batch tests indicated the nanoparticles could effectively immobilize Cr(VI) in soil. At Cr(VI) concentrations of 56.01-502.21 mg/kg, the reducing capacity of CMC-nFeS was 54.68-198.74 mg Cr(VI)/g FeS. Following treatment with CMC-nFeS, the leachabilities of Cr(VI) and Cr_total determined by the Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP) and Physiologically Based Extraction Test (PBET) decreased significantly after 24 h and remained stable for 90 days. Column tests with water and simulated acid rain showed the injection of CMC-nFeS significantly increased the fixed Cr concentration and the procedure was environmentally friendly. Furthermore, analysis of the reaction mechanism demonstrated the best removal obtained in a neutral environment and Cr(VI) was reduced and immobilized in the form of Cr(OH)₃ and Fe_0.75Cr_0.25OOH confirmed by SEM-EDS and XPS analysis.

Keywords: CMC-nFeS; Cr(VI)-contaminated soil; Leaching stability; Long-term stability; Mechanisms.

Publication types

Research Support, Non-U.S. Gov't