Table 5.
Heavy metal contents in water column of pilot wetland along water flow pathways
| Site | TSS mg/L | Mn mg/L | Cd μg/L | Cr μg/L | Cu μg/L | Ni μg/L | Zn μg/L | Pb μg/L |
|---|---|---|---|---|---|---|---|---|
| E1 | 93.3 | 0.17 | <1 | 2.27 | 4.31 | 1.49 | 94.22 | 3.00 |
| E2 | 98.7 | 0.14 | <1 | 1.66 | 3.51 | 0.93 | 25.10 | 2.29 |
| E3 | 86.0 | 0.08 | <1 | 1.00 | 3.38 | 0.74 | 18.23 | 2.62 |
| E4 | 51.3 | 0.04 | <1 | 1.20 | 2.59 | 0.52 | 21.29 | 1.91 |
| E5 | 48.7 | 0.05 | <1 | 0.64 | 3.48 | 0.21 | 15.42 | 1.72 |
| E6 | 48.7 | 0.05 | <1 | 1.72 | 4.04 | 0.32 | 39.99 | 2.22 |
| RR | 47.8% | 70.6% | / | 24.2% | 6.3% | 78.5% | 57.6% | 26.0% |
| W1 | 83.3 | 0.14 | <1 | 1.11 | 2.90 | 0.99 | 41.44 | 2.01 |
| W2 | 52.7 | 0.15 | <1 | 2.18 | 5.86 | 1.14 | 39.16 | 4.07 |
| W3 | 82.0 | 0.12 | <1 | 2.19 | 3.98 | 1.13 | 19.47 | 2.28 |
| W4 | 86.0 | 0.08 | <1 | 2.13 | 5.26 | 0.63 | 18.94 | 2.04 |
| W5 | 28.7 | 0.07 | <1 | 2.39 | 4.67 | 0.48 | 21.37 | 2.67 |
| W6 | 52.0 | 0.08 | <1 | 2.37 | 2.87 | 0.33 | 16.73 | 1.86 |
| RR | 37.6% | 42.9% | / | / | 1.0% | 66.7% | 59.6% | 7.5% |
| Limit | NA | 0.1 | ≤1 | ≤10 | ≤10 | 20 | ≤50 | ≤10 |
Note: RR: removal rate; NA: not available; italic data are above the limits of basic indexes for grade I or supplementary indexes for centralized domestic drinking water sources according to Chinese environmental quality standards for surface water (GB 3838–2002).