Heavy Metals are a Source of Environmental Pollution:
Essential heavy metals — Zn, Cu, Mn, Co
Non-essential Heavy metals — Cd, Pb, Hg, Cr
Cr (chromium) is a heavy metal with risk to
Not biologically degraded in soil.
Present in soil as:
Free metal ions,
Soluble metal complexes (sequestered to ligands),
Exchangeable metals ions, organically bound metals,
Precipitated or insoluble compounds such as oxides
carbonates and hydroxides.
May form part of the structure of silicate materials
(indigenous soil content).