Research Article
Dissolution of Metals from Biosolid-Treated Soils by Organic Acid Mixtures
Table 8
Metals release kinetics of control Romona soil in different concentrations of organic acid (OA) mixtures.
| Element | OA concentration | Metal concentration (mg kg−1) | 15 min | 30 min | 1 hr | 2 hrs | 4 hrs | 8 hrs | 24 hrs | 48 hrs |
| Cd | 0.001 M | 0.0013 | 0.0014 | 0.0015 | 0.0015 | 0.0016 | 0.0017 | 0.002 | 0.002 | 0.01 M | 0.0084 | 0.0088 | 0.0091 | 0.0097 | 0.0102 | 0.0115 | 0.0137 | 0.014 | 0.1 M | 0.020 | 0.021 | 0.022 | 0.023 | 0.025 | 0.027 | 0.031 | 0.032 |
| Cr | 0.001 M | 0.010 | 0.012 | 0.013 | 0.016 | 0.019 | 0.023 | 0.034 | 0.035 | 0.01 M | 0.015 | 0.018 | 0.020 | 0.023 | 0.028 | 0.035 | 0.052 | 0.053 | 0.1 M | 0.11 | 0.13 | 0.14 | 0.16 | 0.20 | 0.23 | 0.35 | 0.36 |
| Cu | 0.001 M | 0.1071 | 0.1139 | 0.1207 | 0.1275 | 0.1343 | 0.1433 | 0.170 | 0.177 | 0.01 M | 0.35 | 0.36 | 0.39 | 0.41 | 0.44 | 0.47 | 0.56 | 0.58 | 0.1 M | 1.97 | 2.03 | 2.12 | 2.21 | 2.34 | 2.51 | 3.11 | 3.17 |
| Ni | 0.001 M | 0.0603 | 0.063 | 0.0675 | 0.0702 | 0.0737 | 0.0773 | 0.0891 | 0.090 | 0.01 M | 0.39 | 0.42 | 0.47 | 0.48 | 0.51 | 0.53 | 0.63 | 0.64 | 0.1 M | 1.07 | 1.12 | 1.18 | 1.24 | 1.33 | 1.42 | 1.64 | 1.67 |
| Pb | 0.001 M | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | 0.01 M | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | 0.1 M | 0.014 | 0.016 | 0.017 | 0.019 | 0.024 | 0.030 | 0.042 | 0.044 |
| Zn | 0.001 M | 0.30 | 0.32 | 0.34 | 0.35 | 0.37 | 0.38 | 0.44 | 0.45 | 0.01 M | 1.95 | 2.06 | 2.17 | 2.26 | 2.34 | 2.44 | 2.77 | 2.79 | 0.1 M | 5.3 | 5.6 | 6.0 | 6.2 | 6.5 | 6.8 | 7.8 | 7.9 |
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Concentration was below detection limits of the AAS for Pb = 0.001 mg kg−1.
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