Effects of freshwater leaching on potential bioavailability of heavy metals in tidal flat soils.
Leaching experiments were conducted to investigate the effects of desalination levels and sediment depths on potential bioavailability of heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in tidal flat soils. The data showed that both the desalination levels (p < 0.001) and soil depths (p < 0.001) had significant effects on the concentrations of acid-volatile sulfide (AVS). AVS concentrations generally exhibited increasing trends with an increase in depth and decreasing trends with enhanced desalination levels. The desalination levels had significant (p < 0.05) effects on the concentrations of simultaneously extracted metal (SEM; Cd, Cr, Cu, Fe, Mn, Pb, and Zn). Moreover, the concentrations of SEM (Cd, Cr, Cu, Fe, Mn, Pb, and Zn) generally tended to decrease with an increase in the desalination level. The desalination treatment significantly reduced the ratios of SEM/AVS compared with control. However, the ratios of SEM/AVS increased with enhanced desalination levels in treatments. Results reveal that low desalination treatment is better for reducing toxicity to benthic organisms than high desalination treatment. Since these reclaimed tidal flats with low desalinisation are suitable for saline water aquaculture, transforming the present land use of reclaimed tidal flats from fresh water aquaculture into saline water aquaculture may reduce health risk of heavy metals remained in sediments. These results will also contribute to our understanding of the dynamic behavior of heavy metals in the reclamation of tidal flats during leaching and the role of the ratio of SEM/AVS predictions on assessing the ecological risks of reclaimed tidal flats.
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.|Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, 510632, China.
Hui
H
Li
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Jun
J
Lu
School of Environment, Jinan University, Guangzhou, 510632, China. liqusheng@sina.com.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China. liqusheng@sina.com.
Qu-Sheng
QS
Li
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Bao-Yan
BY
He
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Xiu-Qin
XQ
Mei
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Dan-Ping
DP
Yu
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Zhi-Min
ZM
Xu
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Shi-Hong
SH
Guo
School of Environment, Jinan University, Guangzhou, 510632, China.|Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation, Department of Education of Guangdong Province, Guangzhou, 510632, China.
Hui-Jun
HJ
Chen
D059001:Aquatic Organisms / Q000378:metabolism*; D001682:Biological Availability; D002681:China; D005618:Fresh Water / Q000032:analysis; D019015:Geologic Sediments / Q000032:analysis*; D019216:Metals, Heavy / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D018570:Risk Assessment; D000068357:Saline Waters / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
Acid-volatile sulfide; Heavy metal; Leaching; Reclamation; Salinity; Tidal sediment