Microwave-enhanced simultaneous immobilization of lead and arsenic in a field soil using ferrous sulfate

Wang Jianle; Zeng Gongchang; Deng Hong; Liu Xueming; Zhao Dongye

doi:10.1016/j.chemosphere.2022.136388

Microwave-enhanced simultaneous immobilization of lead and arsenic in a field soil using ferrous sulfate

Chemosphere. 2022 Dec;308(Pt 2):136388. doi: 10.1016/j.chemosphere.2022.136388. Epub 2022 Sep 8.

Authors

Wang Jianle¹, Zeng Gongchang¹, Deng Hong², Liu Xueming³, Zhao Dongye⁴

Affiliations

¹ School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Resource Recycling, South China University of Technology, Guangzhou, 510006, China.
² School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Resource Recycling, South China University of Technology, Guangzhou, 510006, China; Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters (Ministry of Education), Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, South China University of Technology, Guangzhou, 510006, PR China. Electronic address: dengh2016@scut.edu.cn.
³ School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Resource Recycling, South China University of Technology, Guangzhou, 510006, China; Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters (Ministry of Education), Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, South China University of Technology, Guangzhou, 510006, PR China.
⁴ Department of Civil and Environmental Engineering, Auburn University, Auburn, AL, 36849, USA; Department of Civil, Construction and Environmental Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182, USA. Electronic address: dzhao2@sdsu.edu.

PMID: 36088963
DOI: 10.1016/j.chemosphere.2022.136388

Abstract

Remediation of soil contaminated by mixed heavy metals and metalloids has been a major challenge in the global environmental field. To address this critical issue, we tested a new technology for simultaneous immobilization of lead (Pb) and arsenic (As) in a field contaminated soil using a microwave-assisted FeSO₄·7H₂O treatment process. The process was able to rapidly reduce the TCLP-based leachability of Pb from 12.74 to 0.1 mg L^-1 and As from 2.704 to 0.002 mg L^-1 (MW power = 800 W, Irradiation time = 20 min, and FeSO₄·7H₂O = 4 wt%). The effects of FeSO₄·7H₂O dosage, microwave power, and irradiation time were determined and optimized. After 365 days of curing under atmospheric conditions, the TCLP-leached concentration of Pb and As in the treated soil remained below the regulatory limits of 0.1 and 0.002 mg L^-1, respectively. The microwave irradiation promoted the formation of insoluble PbSO₄(s) and Fe₃(AsO₄)₂·8H₂O(s), resulting in the long-term stability of Pb and As in the soil. The technology offers an effective alternative for remediation of Pb- and/or As-contaminated soil and groundwater.

Keywords: Ferrous sulfate; Groundwater contamination; Heavy metal; Metal immobilization; Metalloid; Microwave-facilitated reaction.

MeSH terms

Arsenic* / analysis
Ferrous Compounds
Lead
Metals, Heavy*
Microwaves
Soil
Soil Pollutants* / analysis

Substances

Ferrous Compounds
Metals, Heavy
Soil
Soil Pollutants
Lead
ferrous sulfate
Arsenic