Study of the organic matter and leaching process from municipal treatment sludge

Abstract
A municipal treatment sludge has been characterized by fractionating the organic content by using acid and basic solutions. The release process has been carried out with a carbonic acid solution (pH=4)/simulating meteoric leaching conditions. Elemental and functional group analysis, FTIR and 13C‐NMR spectra, thermogravimetric analysis were carried out on the different obtained fractions. Metals are mainly linked to the humic acid‐like fraction. The metal‐organic matter bonds permit the release of copper and lead at low extent while zinc and manganese through an acid‐base mechanism (pH=4) are released up to about 90% of their content. The carbonic acid solution is able to splubilize some organic compounds having aliphatic character and containing a great quantity of nitrogen. The study will continue considering the interactions that may occur between the soluble organic substances and the components of soils.