The Impact of Organic Matter Oxidation On the Speciation of Heavy Metals in Sewage Sludge.

The long term fate of heavy metals in sewage sludge amended soils remains debated. While organic matter oxidation may result in the release of heavy metals to the environment, the soil inorganic fraction may play a role in immobilizing these metals. The objective of this study is to assess the impact of organic matter oxidation on the speciation of heavy metals in sewage sludge.  To achieve the objective, sewage sludge of various ages (6 months, 5years, and 10 years old) will be collected from a WWT plant and one group will be subject to air oxidation, while the other will be subject to chemical oxidation using hydrogen peroxide. The speciation of metals will be determined at various stages of oxidation using chemical fractionation. This research is expected to provide insight into the fate of heavy metals in sewage sludge amended soils.