Non-Pyrogenic Formation of Condensed Aromatic Compounds in Iron-Rich Environments

Abstract

Summary Examination of wood decking that has been subjected to environmental change for about a decade in contact with Fe nails in the absence of sunlight shows significant modification due to active Fenton chemistry. The wood is blackened and the analysis of benzenepolycarboxylic acids shows that polycondensed aromatic molecules, commonly associated with black carbon from pyrogenic sources, are formed from the lignin abiotically and without pyrolysis. Because this transformation process occurs globally in soils, these results indicate that black carbon found globally in soils and other natural environments may not be exclusively from pyrogenic sources and that Fenton oxidation of wood is capable of producing black carbon. Such a finding will have an impact on the validity of global estimates of pyrogenic black carbon inputs to the environment.