Humic acids were extracted from different composts and have been
characterized by chemical and spectroscopiC methods. Meaningful differences il) the
cornposiuon were revealed by UV. Visible and IR spectroscopies. The obtained data
showed that carbon. hydrogen and nitrogen of the studied humic acids were slightly
affected by the source of the humic acids, indicating thallhese humic aclds appeared
to be closely related structurally. However, the CIH and OIH values for Yan-HA were
higher than the other h~mic acids. This could Indicate that this humic acid Is more
humified and in a more condensed state. The UV and VIsible spectra of the isolated
humic acids .exhlblted the same trend showing no minimum or maximum absorpjion.
San..HA and Enz-HA have the \coNes! value of E.JEe ratio Indicating 8 higher degr~e 01
aromatic condensation and low aliphatic structure. The IR spectra o( Ihe studied
humic acids Indicated that, there was a broad similarity among the different humic
aelds studied. The intensities of the absorption band vary slightly from one to other.
They differ mainly in the ratios of the number of functional groups and the degr'1e of
polymerization. On the other hand, humic acid extracted (rom sludge (Bos-HA)
contains the highest percentage o( aliphaHc carbon, associated with polysacchar des
structures.