Trace Element Concentrations in Soil, Corn Leaves, and Grain after Cessation of Biosolids Applications
- Thomas C. Granato *a,
- Richard I. Pietza,
- George J. Knaflb,
- Carl R. Carlsonc,
- Prakasam Tatad and
- Cecil Lue-Hingad
- a Research and Development Complex, 6001 West Pershing Road, Cicero, IL 60804
b Yale University, School of Nursing, New Haven, CT 06536-0740
c Metropolitan Water Reclamation District of Greater Chicago, Fulton County Laboratory, Canton, IL 61520
d Metropolitan Water Reclamation District of Greater Chicago, retired
From 1974 to 1984, 543 Mg ha−1 of biosolids were applied to portions of a land-reclamation site in Fulton County, IL. Soil organic C increased to 5.1% then decreased significantly (p < 0.01) to 3.8% following cessation of biosolids applications (1985–1997). Metal concentrations in amended soils (1995–1997) were not significantly different (p > 0.05) (Ni and Zn) or were significantly lower (p < 0.05) (6.4% for Cd and 8.4% for Cu) than concentrations from 1985–1987. For the same biosolids-amended fields, metal concentrations in corn (Zea mays L.) either remained the same (p > 0.05, grain Cu and Zn) or decreased (p < 0.05, grain Cd and Ni, leaf Cd, Cu, Ni, Zn) for plants grown in 1995–1997 compared with plants grown immediately following termination of biosolids applications (1985–1987). Biosolids application increased (p < 0.05) Cd and Zn concentrations in grain compared with unamended fields (0.01 to 0.10 mg kg−1 for Cd and 23 to 28 mg kg−1 for Zn) but had no effect (p > 0.05) on grain Ni concentrations. Biosolids reduced (p < 0.05) Cu concentration in grain compared with grain from unamended fields (1.9 to 1.5 mg kg−1). Biosolids increased (p < 0.05) Cd, Ni, and Zn concentrations in leaves compared with unamended fields (0.3 to 5.6 mg kg−1 for Cd, 0.2 to 0.5 mg kg−1 for Ni, and 32 to 87 mg kg−1 for Zn), but had no significant effect (p > 0.05) on leaf Cu concentrations. Based on results from this field study, USEPA's Part 503 risk model overpredicted transfer of these metals from biosolids-amended soil to corn.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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