Table 9: Metals of control and biosolid-treated soils solubilized by organic acid (OA) mixtures in the first 15 minutes of equilibration.

Biosolid treatmentConcentration of OA mixturesMetals dissolved in 15 minutes
(% of total dissolved)
CdCrCuNiPbZn

Control0.001 M63296167n.d.67
0.01 M60286061n.d.70
0.1 M633162643267

135 Mg ha−10.001 M603061663270
0.01 M603260613069
0.1 M623460603473

1,080 Mg ha−10.001 M663062672866
0.01 M663361663370
0.1 M672961673373

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.