d34S- and d18O-Investigations of Industrially Contaminated Freiberg Soil (W-E-Transect), Lake Water, Lake Sediment Profiles and of Freiberg Mining Water

Joachim D. Pilot Freiberg University of Mining and Technology, Institute for Mineralogy, 09596 Freiberg, Germany

pilot@mineral.tu-freiberg.de

H. Roy Krouse University of Calgary, Dep. of Physics and Astronomy, Stable Isotopes, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4

Frank Haubrich Freiberg University of Mining and Technology, Institute for Mineralogy, 09596 Freiberg, Germany

Three smelters to the east and north of the town Freiberg, Saxony, Germany, have processed sulphide ores of different origin since a long time emitting heavy metals and sulpur compounds until 1990. At the eastern border of the town a plant - the socalled "Zinkhütte" - manufactured sulfuric acid since more than thirtyfive years. Former heavy metall trace element investigations (Voland et al., 1991) showed strong contamination zones of long elliptical shape in SE direction from Freiberg.

To assess the sulphur loading of the environment by these industrial operations, S-content and d34S-values were obtained for soil and grass from two traverses through Freiberg, one W-E- traverse beginning west of Freiberg (Pilot and Krouse, 1991), 22 km long, and the second NW-SE traverse beginning at the east border of Freiberg, 14 km long (Haubrich, 1993). Soil of the parts of these traverses east near Freiberg (especially the A-horizon) have elevated levels of sulphur, Pb, Cu, Ag, Sn and V decreasing to the more far east and south-east end of the traverses; in the contrary, d34S-values increases (from 3 to some 8”) .This may indicate the influence of two kinds of sulphur:
(1) sulphur in the whole region originated from burning of brown-coal with d34S-values around 10”, and (2) sulphur from the emitting smelters with the lower d34S around 0”.

Further, we investigated 8 sediment profiles of 3 lakes in Freiberg, of one lake at the village Zug 3 km south of Freiberg and one of the village Großhartmannsdorf 15 km south of Freiberg, outside the contamination-zone. The d34S-pattern of the lakes in Freiberg differ distincly from the other two: Freiberg lakes (Kreuzteiche) display negative d34S-values between -5 and -20 ” ; this is quite out of the d34S range of the soil and grass transects and of leaf-sulphat from trees in Freiberg and Zug in this year. The lakes of Zug and Großhartmannsdorf have d34S-values between -3 and +16”, enclosing the d34S range of the soil and grass traverses and of leaves. d18O ranges for the soil and grass traverses (insofar determined) and all lake sediments (leachable sulphat) between 3 and 12”.

The water-sulphat of the freiberg lakes show in winter and summer 1994 in the sequence of the four lakes increasing d34S (4 to 10”) and increasing d18O-values (4 to 8”). A possible reason for this may be partially bacterial reduction of the solved sulphat and precipitation of the formed (light-sulphur-) H2S; but this increasing pattern was in summer 1995 very small. The d18O-values with a range from 3 to 10” are similiar to the soil/grass traverse and lake sediment values.

The lake sediments seem to reflect the local conditions of this site. But many profiles display at the top the most light sulphur; it is the question whether this may indicate an environmental (time) feature.

The sulphat of 3 flowing waters from Freiberg mines have d34S near 0”. A fourth site gave the higher value of 2.6” possibly indicating input of surface sulphur. (d18O between 1 and 4.7”)

References

Haubrich, F., Unpubl. Diplom - thesis at the Freiberg University of Mining and Technology (1993).

Pilot, J.D. & Krouse, H.R., Proceedings of the Workshop: "Sulfur transformations in soil ecosystems", 5. - 7. Nov. 1992, Saskatoon, Sask. Canada (1992).

Voland, B., Kluge, A., Schlenker, U., Hoppe, T., Metzner, I., Klemm, W., & Bombach, G., Assessment of the loading of heavy metals in the soils of the region of Freiberg. Research report, Freiberg University of Mining and Technology (1991).