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

Concentration was below detection limits of the AAS for Pb = 0.001 mg kg⁻¹.