Humus moieties

Humic and fulvic acids contain various types of phenolic and carboxylic functional (hydrophilic) groups as well as aromatic and aliphatic moieties which import hydro-phobic properties to these substances. Fig. 4.12 gives a schematic idea on the composition of these substances. We refer to the book of Thurman (1985) and Aiken et al. (1985) for a description of the various properties of humic and fulvic acids in soils and waters and the book by Buffle (1988) for the coordinating properties of humus and humic acids. 

The diverse nature of chemical bonding arrangements exhibited by humus enables the formation of associations both with non-humic materials and with other humic materials to create a dynamic structure. Such a structure is capable of undergoing inter- and intra-molecular bonding to add or lose constituents or change configuration in response to ambient conditions. The chemically diverse and highly reactive nature of the humic matrix imparts the ability of humus both to lose and to acquire molecular moieties in a dynamic manner. 

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