Table 5.
Presence of heavy metals in pond sediment and water of pangasius and tilapia ponds (Mean ± SE).
| Heavy metals | Pangasius ponds (n = 15) |
Tilapia ponds (n = 15) |
p value | ||
|---|---|---|---|---|---|
| Old (n = 8) | New (n = 7) | Old (n = 9) | New (n = 6) | ||
| Presence of heavy metals in pond sludge/sediment | |||||
| Hg (ppm) | 0.0 ± 0.0 | 0.0 ± 0.0 | 0.0 ± 0.0 | 0.0 ± 0.0 | – |
| Cd (ppb) | 0.25 ± 0.12 | 0.22 ± 0.06 | 0.20 ± 0.05 | 0.27 ± 0.08 | 0.997 |
| Pb (ppm) | 27.21 ± 3.22 | 25.93 ± 6.09 | 20.69 ± 2.47 | 17. 97 ± 1.06 | 0.376 |
| Cr(ppm) | 31.13 ± 6.11a* | 23.39 ± 10.39a | 18.04 ± 6.95a | 10.30 ± 0.57b | 0.038 |
| Zn (ppm) | 75.03 ± 8.20 | 72.98 ± 6.09 | 72.33 ± 5.13 | 75.67 ± 5.01 | 0.230 |
| As (ppm) | 43.67 ± 11.54a | 42.28 ± 7.57a | 33.13 ± 5.37b | 31.74 ± 5.23b | 0.052 |
| Presence of heavy metals in the water | |||||
| Hg (ppm) | NF | NF | NF | NF | – |
| Cd (ppb) | 0.01 ± 0.00 | NF | NF | NF | – |
| Pb (ppm) | 0.27 ± 0.05b* | 0.09 ± 0.19a | 0.04 ± 0.01a | 0.03 ± 0.01a | 0.055 |
| Cr (ppm) | 0.05 ± 0.01b | 0.37 ± 0.02a | 0.13 ± 0.01b | 0.07 ± 0.01b | 0.038 |
| Zn (ppm) | 0.03 ± 0.01 | 0.02 ± 0.00 | 0.02 ± 0.00 | 0.01 ± 0.00 | 0.729 |
| As (ppm) | 0.07 ± 0.01a | 0.09 ± 0.02a | 0.18 ± 0.03b | 0.04 ± 0.01a | 0.024 |
*Figures with similar superscripts in a row do not indicate significant difference (p<0.05). NF = Not found.