Chemical characteristics of dissolved organic matter during composting of different organic wastes assessed by 13C CPMAS NMR spectroscopy

This research aimed at assessing the chemical changes occurring in DOM extracted from different composting substrates by means of 13C CPMAS NMR spectroscopy. During composting a reduction of carbohydrates and an increase of aromatic, phenolic, carboxylic and carbonylic C were observed. The highest increase in alkyl C and the lowest increase in aromatic C were explained by the presence of hardly degradable pine needles in the substrate, whereas the highest reduction in carbohydrates and the highest increase of the alkyl C/O-alkyl C ratio were attributed to the presence of highly degradable materials such as spent yeast from beer production.