Concentrations of Cd, Cr, Pb, Zn, Ca, Mg, Al, Fe and Mn in different soil particle-size fractionsa.
| Heavy metal | Concentration of metals (mg kg−1) | |||
|---|---|---|---|---|
| Original | Coarse sand | Fine sand | Silty clay | |
| Cd | 646.7 ± 46.0ab | 629.3 ± 34.9b | 665.7 ± 4.3 ab | 700.6 ± 2.1a |
| Cr | 4802 ± 161.1b | 4930 ± 67.7 ab | 5671 ± 46.3a | 4213 ± 94.2b |
| Pb | 9587 ± 654.9c | 6884 ± 45.0d | 13 115 ± 26.7a | 10 625 ± 565.7b |
| Zn | 20 079 ± 615.5b | 15 508 ± 596.5d | 18 967 ± 96.6c | 24 137 ± 219.9a |
| Ca | 22 007 ± 565.7bc | 32 587 ± 1330.1a | 22 940 ± 433.0b | 21 105 ± 257.2c |
| Mg | 3641.7 ± 85.6b | 3085.8 ± 69.7d | 3244.2 ± 27.7c | 4559.2 ± 65.1a |
| Al | 41 775 ± 346.4c | 50 813 ± 1339.9a | 39 100 ± 229.1d | 45 450 ± 1039.5b |
| Fe | 44 942 ± 1410.3b | 23 046 ± 1545.5d | 41 275 ± 125.0c | 60 950 ± 1477.3a |
| Mn | 63 583 ± 1418.0b | 38 281 ± 1962.6c | 73 258 ± 262.6a | 62 550 ± 433.7b |
a
Different letters (a–d) behind the data indicate a significant difference among different particle-size fractions of soil (one-way ANOVA, P < 0.05).