Dissolution of Metals from Biosolid-Treated Soils by Organic Acid Mixtures

Table 2

Amounts of Cd extracted by organic acid (OA) mixtures of various compositions and concentrations.

OA concentration	OA composition	Cd concentration (mg kg^−1)
		Biosolid	Standard
0.1 M	2nd	2.11	1.86
	4th	2.36	2.58
	8th	1.98	1.63
	12th	1.79	1.60
	16th	1.71	1.62
0.01 M	2nd	0.39	0.31
	4th	0.41	0.43
	8th	0.44	0.35
	12th	0.47	0.37
	16th	0.51	0.43
0.001 M	2nd	0.29	0.20
	4th	0.32	0.24
	8th	0.36	0.32
	12th	0.29	0.23
	16th	0.30	0.29
13.5 mM Ca(NO3)2	Not applicable	0.10

Values represent means of four replicates. The differences of Cd concentrations among the OA compositions of growth periods were tested by one-way ANOVA. In each column of each organic concentration, values followed by the same uppercase letter were not significantly different at . The differences of the Cd concentrations between standard (STD) and biosolid (BSL) treatments were tested by Student-Newman-Keuls test. Each pair of Cd concentrations followed by the same lowercase letter was not significantly different at .
Compositions corresponding to OAs recovered from STD and BSL-treated medium of corn at 2nd, 4th, 8th, 12th, and 16th weeks of growth.