Composition and Spectroscopic Characteristics of Humic Substances in a Landfill

Abstract:

Humic acids(HA) and fulvic acids(FA)extracted from the aged refuse samples in Shanghai Laogang MSW Landfill site were characterized by elemental analysis,FTIR and 13C CP/MAS NMR.The results show that lignin and aromatic compounds,the major components of HA,are apparently more in HA than in FA.The proportion of alkyl-C in HA is also higher than that in FA.On the contrary,carboxylic acid groups are of large proportion in FA,and the oxy carbons related to cyclic polysaccharide are more in FA than those in HA.The degrees of aromatic condensation and stability of HA are higher than those of FA.On the other hand,with the increasing of the landfill age,the aromaticity and satability of HA increase while the content of oxygen-containing groups especially carboxylic acid in FA decreases.The degree of humification of both HA and FA increase with the increasing of landfill age.