Study of water - extractable fractions from South Moravian lignite

journal article in Web of Science

English

Lignite can be applied directly in natural form on agricultural fields as a soil conditioner. However there is little information on leaching of risky compounds by its interaction with water. South Moravian lignite was therefore extracted with water at 25 C and 2.3% of water-soluble fractions were obtained from lignite corresponding to 0.3% of total organic carbon. All ten fractions form aromatic and aliphatic structures with oxygen containing functional groups such as carboxyl groups, alcohols, ethers, esters, and fractions can be characterized as fulvic-like and humic-like substances. According to the XPS spectra, the fractions contain two nitrogen forms, one of which is ascribed to pyrroles and the second is related to protonated amines or quaternary nitrogen. Analysis at molecular level showed that the fractions contain compounds such as benzene carboxylic acids and their derivatives, small aliphatic diacids, fatty acids and polyols. Most of the identified molecules reflect clearly the origin from microbial degradation.The differences between the individual fractions are negligible, especially after 21 days of extraction. From environmental points' of view, it seems that the identified compounds do not represent a toxic risk.

lignite; water - soluble fractions; fulvic acid; humic acid; organic matter

DOSKOČIL, L.; GRASSET, L.; ENEV, V.; KALINA, L.; PEKAŘ, M.

2015

13. 3. 2015

1866-6280

ENVIRON EARTH SCI

73

7

Federal Republic of Germany

3873

3885

13