IMPACT OF BROWN-COAL DUST ON THE ORGANIC-MATTER IN PARTICLE-SIZE FRACTIONS OF A MOLLISOL

The influence of brown coal emissions from a briquette factory on the organic matter of a Mollisol has been investigated. Non-contaminated, heavily contaminated soils and airborne particles are compared by usin g chemical and spectroscopic methods (C-13 CPMAS-NMR, Py-GC-MS, C-14 d ating). Bulk soils as well as their particle-size fractions are invest igated. Organic carbon content of the bulk contaminated soil (138.6 g C/kg) is higher by a factor of six than the non-contaminated soil. For particle-size fractions, the highest content of organic carbon is fou nd in the fine sand fraction (347.2 g C/kg). Furthermore, organic matt er of the contaminated site shows a trend for relatively higher abunda nce of aliphatic compounds in the fraction ranging from 6 to 2000 mu m , whereas for particles < 6 mu m no trend was observed. The A horizon of the contaminated soil is much older (15,750 yr BP) than the noncont aminated soil which indicates input of anthropogenic material. Py-GC-M S analyses show for the non-contaminated site a homologous series of m ainly alkanes, low amounts of prist-1-ene and a high abundance of lign in- and carbohydrate-derived structures. In contrast, composition of t he samples from the contaminated site are similar to a sample of brown coal analyzed and show a homologous series of n-alkane, alkene, alpha , omega-alkadiene triplets and a high relative abundance of prist-1-en e with few lignin derived compounds, except for the clay fraction. Ref lected light microscopy shows large amounts of brown coal dust particl es with typical maceral groups, huminite, liptinite, and inertinite, i n the fine sand fraction from the contaminated soil. Additionally, min or amounts of thermally altered brown coal-derived particles, i.e. cok e particles, are observed. Copyright (C) 1996 Elsevier Science Ltd.