title: Leaching heavy metals from the surface soil of reclaimed tidal flat by alternating seawater inundation and air drying.
abstract: Leaching experiments were conducted in a greenhouse to simulate seawater leaching combined with alternating seawater inundation and air drying. We investigated the heavy metal release of soils caused by changes associated with seawater inundation/air drying cycles in the reclaimed soils. After the treatment, the contents of all heavy metals (Cd, Pb, Cr, and Cu), except Zn, in surface soil significantly decreased (P < 0.05), with removal rates ranging from 10% to 51%. The amounts of the exchangeable, carbonate, reducible, and oxidizable fractions also significantly decreased (P < 0.05). Moreover, prolonged seawater inundation enhanced the release of heavy metals. Measurement of diffusive gradients in thin films indicated that seawater inundation significantly increased the re-mobility of heavy metals. During seawater inundation, iron oxide reduction induced the release of heavy metals in the reducible fraction. Decomposition of organic matter, and complexation with dissolved organic carbon decreased the amount of heavy metals in the oxidizable fraction. Furthermore, complexation of chloride ions and competition of cations during seawater inundation and/or leaching decreased the levels of heavy metals in the exchangeable fraction. By contrast, air drying significantly enhanced the concentration of heavy metals in the exchangeable fraction. Therefore, the removal of heavy metals in the exchangeable fraction can be enhanced during subsequent leaching with seawater.
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Department of Ecology, Jinan University, Guangzhou, 510632, China.
authors.forename: Shi-Hong
authors.initials: SH
authors.lastname: Guo
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Liu
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China. Electronic address: liqusheng@21cn.com.
authors.forename: Qu-Sheng
authors.initials: QS
authors.lastname: Li
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yang
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Bao-Yan
authors.initials: BY
authors.lastname: He
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Xu
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China; Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, Guangzhou, 510632, China.
authors.forename: Jin-Shao
authors.initials: JS
authors.lastname: Ye
authors.affiliation: Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
authors.forename: Eddy Y
authors.initials: EY
authors.lastname: Zeng
mesh_terms: D002681:China; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005290:Ferric Compounds / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D010084:Oxidation-Reduction; D012623:Seawater / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013457:Sulfur Compounds / Q000737:chemistry
chemical_list: D005290:Ferric Compounds; D019216:Metals, Heavy; D009930:Organic Chemicals; D012989:Soil Pollutants; D013457:Sulfur Compounds; C000499:ferric oxide
keywords: DGT; Heavy metals; Iron transformation; Reclamation