TABLE 2.
Sediment physicochemical properties at sampling sites in Hahndorf Creek in relation to the position of a WWTP outfall
| Property (unit of measure) | Value at:
|
|||||
|---|---|---|---|---|---|---|
| 640 m above outfall | Pool above outfall | Pool below outfall | 150 m below outfall | 400 m below outfall (above the dam) | 1,040 m below outfall | |
| E.C. (dS/m) | 0.30 | 0.30 | 0.32 | 0.20 | 1.06 | 0.38 |
| pH | 7.24 | 7.03 | 6.23 | 7.10 | 6.43 | 6.88 |
| Total C (%) | 0.43 | 0.71 | 1.34 | 0.14 | 7.39 | 2.07 |
| Total N (%) | 0.04 | 0.06 | 0.09 | 0.04 | 0.47 | 0.11 |
| NH4-N KCl ext (mg/kg) | 7.77 | 9.96 | 15.22 | 20.82 | 81.75 | 10.44 |
| NO3-N KCl ext (mg/kg) | 0.27 | 0.28 | 0.30 | 0.24 | 1.10 | 0.35 |
| Total P (mg/kg) | 339.53 | 184.20 | 299.26 | 454.80 | 973.25 | 830.16 |
| Total Cu (mg/kg) | 22.39 | 24.72 | 17.01 | 31.69 | 30.43 | 19.28 |
| Total Zn (mg/kg) | 46.40 | 41.18 | 42.05 | 64.90 | 191.32 | 98.42 |
| Ca exch [cmol(+)/kg] | 5.08 | 8.21 | 7.66 | 4.83 | 16.87 | 4.14 |
| Mg exch [cmol(+)/kg] | 4.66 | 7.49 | 7.71 | 4.12 | 9.15 | 2.41 |
| Na exch [cmol(+)/kg] | 1.23 | 1.24 | 1.12 | 1.00 | 1.37 | 0.48 |
| K exch [cmol(+)/kg] | 0.44 | 0.70 | 0.54 | 0.33 | 0.66 | 0.22 |
| Clay (%) | 35.77 | 57.28 | 25.38 | 19.66 | 18.39 | 10.74 |
| Silt (%) | 28.71 | 14.51 | 18.85 | 27.72 | 18.95 | 19.68 |
| Fine sand (%) | 28.70 | 26.26 | 37.77 | 39.57 | 40.62 | 41.04 |
| Coarse sand (%) | 3.04 | 2.38 | 15.94 | 12.51 | 7.34 | 24.99 |