Abstract: Composting is a controlled technology to enhance the
natural aerobic process of organic wastes degradation. The resulting
product is a humified material that is principally recyclable for
agricultural purpose. The composting process is one of the most
important tools for waste management, by the European Community
legislation. In recent years composting has been increasingly used as
a remediation technology to remove biodegradable contaminants
from soil, and to modulate heavy metals bioavailability in
phytoremediation strategies. An optimization in the recovery of
resources from wastes through composting could enhance soil
fertility and promote its use in the remediation biotechnologies of
contaminated soils.
Abstract: Mercury adsorption on soil was investigated at
different ionic strengths using Ca(NO3)2 as a background electrolyte.
Results fitted the Langmuir equation and the adsorption isotherms
reached a plateau at higher equilibrium concentrations. Increasing
ionic strength decreased the sorption of mercury, due to the
competition of Ca ions for the sorption sites in the soils. The
influence of ionic strength was related to the mechanisms of heavy
metal sorption by the soil. These results can be of practical
importance both in the agriculture and contaminated soils since the
solubility of mercury in soils are strictly dependent on the adsorption
and release process.