Table 7: Metals release kinetics of biosolid-treated Romona soil (135 Mg ha−1) in different concentrations of organic acid (OA) mixtures.

ElementOA concentrationMetal concentration (mg kg−1)
15 min30 min1 hr2 hrs4 hrs8 hrs24 hrs48 hrs

Cd0.001 M0.0550.0590.0630.0660.0680.0730.0890.091
0.01 M0.180.190.200.210.230.250.290.30
0.1 M0.790.830.880.921.011.101.261.29

Cr0.001 M0.070.080.090.100.130.160.220.23
0.01 M0.230.270.300.340.380.460.690.71
0.1 M0.911.071.131.231.471.802.632.68

Cu0.001 M0.860.880.920.971.051.151.381.42
0.01 M2.212.352.492.632.802.933.593.66
0.1 M7.67.88.38.99.410.112.612.7

Ni0.001 M0.530.550.590.620.660.680.790.81
0.01 M1.571.671.801.932.012.132.522.57
0.1 M6.87.37.88.48.99.511.011.3

Pb0.001 M0.0210.0230.0250.0300.0350.0440.0630.065
0.01 M0.060.070.080.090.110.130.190.20
0.1 M0.320.340.380.450.530.620.900.94

Zn0.001 M3.964.194.354.484.694.915.605.66
0.01 M21.422.623.324.825.727.130.731.0
0.1 M100103108114117121134137