Biological activity and structure of humic substances

Investigations into the structure and complexity of humic substances 

It is the intention in this current review to indicate only briefly how 

It should, however, be borne in mind that the method of extraction can be 

In most investigations, HA has been used more extensively than FA. It 

Introductory Chapter) one based on that described by Haworth. It is proposed that HA comprises a polycyclic aromatic core material to which are attached carbohydrates, proteins, phenols, mineral components, etc. 

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