25th International Meeting on Organic Geochemistry IMOG 2011

P-143
Phenolic compounds in water leachates of Miocene lignites from
the Konin Brown Coal Basin (Poland)
Monika Fabiańska, Urszula Skręt
University of Silesia, Sosnowiec, Poland (corresponding author:monika.fabianska@us.edu.pl)
High degree of functionality of Miocene lignites
likely renders them susceptible to leaching of organic
matter by water [1]. As Finkelman et al. [2] indicates
such solutions of organic compounds should be
considered the reason of considerable health and
environmental hazard. The first aim of the project
was to determine whether low-weight organic
compounds could be transported outside of the mine
outcrops and/or lignite beds in water solutions and to
what extent. The second one was to identify and
characterize distributions of soluble compounds and
to explore their possible application as a fingerprint
indicating lignite source in future research on
groundwater and soil contamination in the nearby
area.
To this end, ten samples of Miocene lignites were
selected from a set of 65 previously investigated
samples from the Konin Brown Coal Basin (Poland) of
variable litotype and petrography. The highest
dichloromethane (DCM) extract yields and gas
chromatography-mass spectrometry data were used
as a guide. Petrologic analyses were carried out in
reflected, white light. Analytical procedures used in
microscopic studies followed ICCP standards. Waterwashing
processes were simulated by stirring 50 g of
powdered lignites with distilled water (200 ml, 3x30
min). Collected water extracts were filtered and
dissolved organic compounds isolated by solid phase
extraction on BAKERBOND Speediscs PolarPlus
(C18) (procedure as applied for drinking water).
Separated organic phases were analysed by GC-MS
on a HP-5 column, 60 m, id = 0.20 mm (EI mode at
70eV, full scan mode). Compounds were identified by
their spectra, and by comparison with standards
analysed previously and with literature data [3].
While the DCM extraction yields of lignites lie in the
range 0.9-20.2% (wt.), the water-extraction yields fall
in the range 0.001-0.048% (wt.).Extractability of
water-washed lignites was in the range of 0.2-6.0%
(wt.), i.e. much lower than that of non-washed lignites.
The main components of the leachtes are aliphatic
phenol derivatives related to lignins being the main
component of the lignite macromolecule, particularly
in macerals of huminite group. These macerals occur
in ca 59.2-87.5% in the lignites investigated. Phenols
form ca 70-95% of organic phases leached from
lignites. The type of phenols shows unambiguous
relationship to the parent lignite and its biological
origin, i.e. a leachate of deciduous wood-derived
xylithe contained compounds of syringic molecular
structure such as 2,6-dimethoxybenzoquinone and
syringic aldehyde. That phenolic unit is commonly
found in lignin of deciduous trees. More common
were phenolic compounds being guaiacol derivatives
such as ethyl homovanilone, vanilline, homovanilic
acid, and apocynine which indicate conifers input.
Leachate minor components were aliphatic ketones
and aldehydes, aliphatic alcohols and esters of fatty
acids. Aromatic hydrocarbons occur in a limited range
and comprised phenanthrene, fluorene and pyrene
among unsubstituted compounds. In a few leachates
also methyl- and dimethylnaphthalenes were found.
In a view of other environmental investigations the
concentration of water-soluble phenol derivatives and
lighter aromatic compounds in leachates mean a
significant hazard to health and environment [2].
These compounds could be transferred to
groundwater from large open cast mines of lignites
exploited in several large brown coal basins in Poland
and Germany.
References
[1] Stefanova M., Oros D.R., Otto A.. Simoneit B.R.T.
2002, Polar aromatic biomarkers in the Miocene
Maritza-East lignite, Bulgaria, Org. Geochem., 33,
1079-1091.
[2] Finkelman R.B., Orem W.H., Castranova V., Tatu
C.A, Belkin H.E., Zheng B., Lerch H. E., Maharaj
S.V., Bates A.L. 2002. Health impacts of coal and
coal use: possible solutions. <strong>International</strong> Journal
of Coal Geology 50, 425– 443.
[3] The Wiley/NBS Registry of Mass Spectral Data,
Wiley, New York (2000).
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