The technique of DGT (diffusive gradients in thin films) using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China. The DGT results showed significantly positive correlations between Co, Pb, Cd and Mn, and Ni and Fe concentrations in porewater. Cu and Zn showed a significantly negative correlation with Mn, due to Cu combination with carbonates and Zn derived from agricultural pollution, respectively. The rank order of average concentrations of Co, Ni and Cd at each station was DGT1.92>DGT0.78>DGT0.39, suggesting stronger resupply from sediments to porewater when using thicker diffusive gels. Comparing centrifugation and DGT measurements, Co, Ni and Cd are highly labile; Mn and Fe are moderately labile; and Cu, Zn and Pb are slightly labile. The variations of AVS concentrations in sediment cores indicate that metal sulfides in deeper layers are easily diffused into surface sediments.
|Number of pages||11|
|Journal||Journal of Environmental Sciences|
|State||Published - May 1 2015|
Bibliographical noteFunding Information:
This study is supported by the Mega-projects of Science Research for Water Environment Improvement (No. 2012ZX07101-002 ) and the National Natural Science Foundation of China (No. 41303085 ).
- DGT (diffusive gradients in thin films)
- Heavy metals
- Sulfidization process
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Environmental Science (all)