Table 2.
Changes of metal concentrations in the on-site sediment.
| Layer | Sampling date | Metal concentration (mg/kg dry sediment) | |||||
|---|---|---|---|---|---|---|---|
| Na | Mg | Al | K | Ca | Fe | ||
| Uppermosta | Mar. 2012 | 15,650 | 10,626 | 60,561 | 5642 | 8173 | 148,088 |
| Deepb | Dec. 2011 | 16,673 ± 808 | 17,045 ± 398 | 113,292 ± 4022 | 8912 ± 182 | 10,242 ± 38 | 72,139 ± 3467 |
| Mar. 2012 | 20,477 ± 1426 | 18,130 ± 710 | 115,629 ± 2808 | 9083 ± 118 | 9600 ± 343 | 73,939 ± 1514 | |
| Oct. 2013 | 12,035 ± 1367 | 15,440 ± 1649 | 102,379 ± 11,373 | 8456 ± 722 | 9546 ± 865 | 69,636 ± 5783 | |
| Cr | Cu | As | Se | Cd | Pb | ||
| Uppermosta | Mar. 2012 | 30.7 | 44 | 32.5 | 1.8 | 0.19 | 30.5 |
| Deepb | Dec. 2011 | 57.2 ± 1.7 | 123 ± 0.3 | 47.8 ± 1.7 | 2.5 ± 0.1 | 1.1 ± 0.0 | 52.1 ± 0.4 |
| Mar. 2012 | 57.6 ± 1.6 | 120 ± 4.1 | 47.7 ± 1.4 | 3.0 ± 0.1 | 1.1 ± 0.1 | 50.1 ± 0.6 | |
| Oct. 2013 | 53.1 ± 5.2 | 118 ± 11.1 | 43 ± 2.8 | 2.8 ± 0.5 | 1.1 ± 0.1 | 53.3 ± 0.4 | |
a
Sediment sample was collected at 0–2 mm depth from the surface. The measurement was conducted in singlicate because the quantity of obtained sample was small.
b
Sediment samples were collected at 20–40 mm depth from the surface (n = 2) and the symbol “±” means the variation between two replications.