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Airborne Contamination of Forest Soils by Carbonaceous Particles from Industrial Coal Processing
Author(s) -
Schmidt Michael W. I.,
Knicker Heike,
Hatcher Patrick G.,
KögelKnabner Ingrid
Publication year - 2000
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2000.00472425002900030012x
Subject(s) - soil water , podzol , magic angle spinning , organic matter , humus , environmental chemistry , coal , mineralogy , total organic carbon , chemistry , environmental science , soil science , nuclear magnetic resonance spectroscopy , organic chemistry
In the German Ruhr‐area industrial coal processing emitted large amounts of carbonaceous particles for a century until 1970. Our objectives were to detect the presence of airborne carbonaceous particles and assess their impact on the chemical structure of soil organic matter in two forest soils (Podzols) with potential sources of carbonaceous particles approximately 10 to 30 km away. Contamination was not visible macroscopicaily. Organic matter was characterized in bulk soils and in particle‐size separates by elemental analysis, magnetic susceptibility measurement, reflected light microscopy, and 13 C solid‐state nuclear magnetic resonance (NMR) spectroscopy. Organic and mineral horizons contained carbonaceous particles including char, coke, and bituminous coal from coal combustion, coking, coal processing, and steel production. In the organic horizons of both soils we observed a material high in magnetic susceptibility (max. 109 × 10 −8 m 3 kg −1 ), whereas in the mineral horizons only the Podzol with an intense intermixing moder‐type humus had high magnetic susceptibly. This Aeh horizon was extremely rich in organic carbon (139.4 g organic C kg −1 ), concentrated in the 20 to 2000 µm size separates. In the second Podzol, like in many natural soils, C concentrations were largest in the <20 µm separates. Bloch decay 13 C magic angle spinning (MAS) NMR spectroscopy revealed a highly aromatic structure of the carbonaceous particles. Airborne carbonaceous particles formed a macroscopically indistinguishable mixture with natural soil organic matter and could be present in many soils neighboring industrialized areas.