Protonation stabilized high As/F mobility red mud for Pb/As polluted soil remediation

Dazhong Yang; Wanwan Deng; Ao Tan; Zheting Chu; Wenfei Wei; Renji Zheng; Yangzi Shangguan; Atsushi Sasaki; Masatoshi Endo; Hong Chen

doi:10.1016/j.jhazmat.2020.124143

Protonation stabilized high As/F mobility red mud for Pb/As polluted soil remediation

J Hazard Mater. 2021 Feb 15;404(Pt B):124143. doi: 10.1016/j.jhazmat.2020.124143. Epub 2020 Oct 5.

Authors

Affiliations

¹ School of Environmental Science and Engineering, State Environmental Protection Key Laboratory of Integrated Surface Water Groundwater Pollution Control, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen 518055, China.
² School of Architecture and Urban Planning, Shenzhen University, Shenzhen 518060, China.
³ Graduate School of Science and Engineering, Yamagata University, Jhonan 4-3-16 Yonezawa, Yamagata 992-8510, Japan.
⁴ School of Environmental Science and Engineering, State Environmental Protection Key Laboratory of Integrated Surface Water Groundwater Pollution Control, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen 518055, China; College of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 200090, China.
⁵ School of Environmental Science and Engineering, State Environmental Protection Key Laboratory of Integrated Surface Water Groundwater Pollution Control, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: chenh3@sustech.edu.cn.

PMID: 33068993
DOI: 10.1016/j.jhazmat.2020.124143

Abstract

The hazardous red mud (RM) with high As/F mobility and heavy metal contaminated soil have constituted severe environmental threats. This work demonstrates a "waste to eco-material" strategy through a reliable and low-cost protonation approach to eliminate the As/F leaching risk of RM, and then recycle it as heavy metal passivators for Pb/As polluted soil remediation. The As/F anions have been immobilized by the protonated Fe/Al (hydr)oxides within RM via the formation of stable As/F compounds during the protonation process, which satisfies the requirement by the World Health Organization (As leaching <0.01 mg/L; F leaching <0.8 mg/L). Moreover, in the oilseed rape pot experiments, by adding 30 g/kg stabilized RM into Pb/As polluted soils (100 ~ 300 ppm), benefited from its large adsorption capacity, approximately 40.9 ~ 49.7% Pb and 40.8 ~ 54.8% As concentrations in the plant are reduced without adverse effects. The whole process for RM treatment and soil remediation is cost-effective, straightforward and eco-friendly without secondary pollution or soil degradation. This research provides a green chemical strategy to address both RM recycling and heavy metal contaminated soil remediation problems, which shows high economic feasibility and ecological benefits.

Keywords: As/F stabilization; Heavy metal pollution; Red mud; Soil remediation.