Trace-Elements in Precipitation from the Eastern Erzgebirge, Black Triangle

Lutz Lange Institut für Umwelt-Geochemie, Im Neuenheimer Feld 236, D-69120 Heidelberg, Germany

jmt@classic.min.uni-heidelberg.de

Jörg Matschullat Institut für Umwelt-Geochemie, Im Neuenheimer Feld 236, D-69120 Heidelberg, Germany

Situated at the northern rim of the so called "black triangle" between parts of Poland, the Czech Republic and Germany, the eastern Erzgebirge was exposed to unusual high immission concentrations (Möller and Lux, 1992). Among other sources, high emissions from brown coal mining and processing industries in the Bohemian basin were made responsible for the input and the resulting soil and water acidification as well as the pronounced forest decline in extensive areas.

Precipitation samples were collected at five stations over a period of two years (May 92-April 94; Bozau, 1995). Selected trace elements (As, Be, Cd, Co, Cr, Cu, Ni, Pb, Se, V, Zn) were quantified using GF-AAS, TXRF and ICP-MS to determine concentrations and fluxes as a contribution to the project "Element Dispersion in the Eastern Erzgebirge", sponsored by the German Science Foundation (DFG). For the analyst, precipitation samples pose a special problem because of their rather low trace-element concentrations. Few methods are able to quantify these concentrations at the lower ppb (µg/L) and the higher ppt (ng/L) level (Table 1). Most of the analyses were performed with electrothermal atomization (GF-AAS, Zeiss Jena AAS 5EA). To confirm the data and to compare performance of the different methods, selected samples were analyzed with total reflection x-ray analysis (TXRF, Atomica Xtra II) and inductively coupled plasma-mass spectrometry (ICP-MS, Perkin Elmer Elan 5000).

The data from the two year period combined with
meteorological data allows to obtain information on spatial variability and probable transport distance and thus the origin of the pollutants. We intend to further process the data with a numerical simulation model (source receptor).

The previously high immissions prior to 1990 (Möller and Lux, 1992) seem to have declined to average immission concentrations in Central Europe (Matschullat and Bozau, 1996). These results are promising, because they show the success of air pollution control measures in the last few years. At the same time, the quantification of the atmospheric element input is now possible - an important contribution, e.g. for element balance calculations for the catchment area and distinct sub-catchment studies where element flows are being studied from atmospheric input via soil passage to their output with stream waters.

References

Bozau, E., Unpubl doctoral thesis, Earth Sciences, Univ Heidelberg, 144 pp. (1995).

Matschullat, J. & Bozau, E., Appl. Geochem. (1996, in press).

Möller, D. & Lux, H., Schriftenreihe VDI Komm Reinhaltung Luft 18, 308 pp. (1992).

Table 1. Element concentrations in precipitation of the Eastern Erzgebirge (1992-1994).

µg/l As Be Cd Co Cr Cu Ni Pb Se V Zn

median 1,1 0,13 0,25 0,13 0,6 2,4 1,3 11,8 0,3 1,7 30

min. <0,1 0,01 0,1 0,01 0,1 0,1 0,1 0,1 <0,03 0,1 <10

max. 11,8 8,4 1,4 2,09 26,7 53 46 186 2,7 21 280

n 170 173 165 173 171 186 186 182 165 161 232