Summary:
One of the most alternative uses of biodegradable municipal solid wastes is the
process of composting, which aims the production of an added-value product that
can be used as a soil fertilizer. Mature composts contain stable organic matter
(OM), which consists of the most numerous and most metal-reactive components,
behaving as natural multiligand system. Although the amount of compost
dissolved OM (DOM) may be small as compared to the bulk OM, it is recognised as
an important component that controls the mobility and toxicity of metals in
ecosystem. In present work, several compost samples were taken from different
pilot composting units located in Greece. The present study concern the
chemical analysis of four types of composts from different substrates. The
first sample was an industrial compost, the second from a municipal pilot
plant, the third from a domestic pilot system and the fourth was a commercially
available compost from sea wrack. The above composts were submitted to leaching
test with deionized water and analyzed by spectroscopic methods and especially
the Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet–visible
spectroscopy (UVVis), and 3D emission excitation spectrometry (EEM). Finally,
compost leachates were used in order to classify the present DOM to hydrophobic
(pho-DOM), trans-hydrophilic (T-phi-DOM), hydrophilic (phi-DOM) and neutral
hydrophobic -hydrophilic (N-DOM) fractions, the resins DAX-8 and XAD-4 were
used. Binding properties of some heavy metals (Cr, Cu, Mn, Ni, Cd, Pb, Zn) to
isolated DOM fractions was investigated. Prediction of the distribution of
pollutant through metal concentration that detected in each above fractions, is
indicative to each metal stability and mobility and contributes to the
ecosystem conservation.
Keywords:
Mobility, Heavy metals, Compost, Stability
