title: Mercury removal from contaminated soil by thermal treatment with FeCl₃ at reduced temperature.
abstract: Thermal treatment has been used to remediate mercury-contaminated soils; however, existing thermal technologies use high temperatures (e.g., 600-800°C) and require high energy costs. Moreover, the treated soil is unfavorable for agricultural reuse. To address these issues, the present study developed a method for the thermal treatment of mercury-contaminated soils at a reduced temperature (400°C) by adding FeCl3. A FeCl3/Hg molar ratio of 100:1 in the soil was adopted as the optimum dosage of FeCl3 required to achieve maximum reduction of mercury. The mercury concentration in soils was successfully reduced to 0.8 mg kg(-)(1) when treated at 400°C for 60 min and the treated soil retained most of its original soil properties. FeCl3 addition during thermal treatment not only accelerated the volatilization of mercury in the easily removed fraction but also reduced the volatilization temperature of mercury in the hardly removed fraction. The adsorbable organic halogens and PCDD/Fs formed during thermal treatment with FeCl3 would not affect the soil reuse in agriculture. The thermal decontamination method reduces energy costs and leads to agricultural soil reuse, thus providing a greener and more sustainable remediation method for treating mercury-contaminated soil in future engineering applications.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Fujun
authors.initials: F
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Environmental Sciences and Engineering, Liaoning Technical University, Fuxin 123000, China.
authors.forename: Duanping
authors.initials: D
authors.lastname: Xu
authors.affiliation: Geotechnical and Environmental Research Group, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK.
authors.forename: Deyi
authors.initials: D
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Fasheng
authors.initials: F
authors.lastname: Li
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: guqb@craes.org.cn.
authors.forename: Qingbao
authors.initials: Q
authors.lastname: Gu
mesh_terms: D002681:China; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008628:Mercury / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013696:Temperature; D014835:Volatilization
chemical_list: D012989:Soil Pollutants; D008628:Mercury
keywords: Contaminated soil; FeCl(3); Mercury; Thermal treatment