EFFECTS OF MINERALS ON THE TRANSFORMATION OF ORGANIC-MATTER DURING SIMULATED FIRE-INDUCED PYROLYSIS

The effect of Fe(OH)(3), Al(OH)(3), birnessite, montmorillonite, and s ea sand on changes in the composition of organic matter during heating was investigated. CO2 was released in all treatments, although the ex periments were conducted in the absence of oxygen. In the presence of Fe(OH)3, Al(OH)(3), and birnessite, more CO2 was evolved than in the o ther treatments. Birnessite and Fe(OH)3 enhance the thermal decomposit ion of polysaccharides and lignin more than Al(OH)(3). Changes in the lignin signature resembled the alterations during aerobic litter decom position and humification in humus profiles. DRIFT spectra indicate th at the formation of aromatic compounds was favoured, especially in the presence of birnessite. (C) 1997 Elsevier Science Ltd.