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

Table 9

Metals of control and biosolid-treated soils solubilized by organic acid (OA) mixtures in the first 15 minutes of equilibration.

Biosolid treatment	Concentration of OA mixtures	Metals dissolved in 15 minutes
		(% of total dissolved)
		Cd	Cr	Cu	Ni	Pb	Zn
Control	0.001 M	63	29	61	67	n.d.	67
	0.01 M	60	28	60	61	n.d.	70
	0.1 M	63	31	62	64	32	67
135 Mg ha^−1	0.001 M	60	30	61	66	32	70
	0.01 M	60	32	60	61	30	69
	0.1 M	62	34	60	60	34	73
1,080 Mg ha^−1	0.001 M	66	30	62	67	28	66
	0.01 M	66	33	61	66	33	70
	0.1 M	67	29	61	67	33	73

Obtained at Moreno Field Station of the University of California, Riverside, CA. From 1976 through 1981, composted biosolids were applied at dry weight rates of 0 (control), 22.5, and 180 Mg ha⁻¹ yr⁻¹, respectively.
Concentration was below detection limits of the AAS for Pb = 0.001 mg kg⁻¹.