The results of decades of research illustrate that metals in biosolids-amended soils are retained at a higher rate than soils without biosolids-amendments indicating that either an individual or combination of constituents within biosolids is responsible for the elevated sorption capacity of biosolids-amended soils.

The deliberation centers on the accountable component of biosolids as the effective sorbent fraction which may include inorganic phases and/or organic material.

For example, the affinity of metals for organic substances has been well documented in the...