Abstract
Elemental composition of humic acids in the marine sediments collected from Hakata Bay near Muromi River lies within a range reported for those humic acids of marine origin in the literature. FT-IR spectra of the humic acid indicated the presence of such functional groups as hydrogen-bonded -OH, aromatic and aliphatic -CH, -COOH, C=O, C-O-C and amid band. 1H-NMR also showed aliphatic and aromatic characters, which are important for anticipating the presence of humic substances. Pyrolysis-GC/MS suggested that the components of the humic acids are constructed from a wide range of biologically related materials such as proteins, carbohydrates, lipids and phenols. The results suggested that aquatic plants, algae and animal biomasses, mainly compose the humic acids and the contribution of terrestrial source materials such as lignin is small.
